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• 1. [Article] Investigations into the Regional and Local Timescale Variations of Subglacial Drainage Networks

  Subglacial water plays an important role in the regulation of an ice sheet's mass balance. It may be the dominant control on the velocities of ice streams and outlet glaciers on scales of months to millennia. ...

  Citation × Citation Citation Abstract Copy Title: Investigations into the Regional and Local Timescale Variations of Subglacial Drainage Networks Author: Hiester, Justin Year: 2013 Subglacial water plays an important role in the regulation of an ice sheet's mass balance. It may be the dominant control on the velocities of ice streams and outlet glaciers on scales of months to millennia. Recent satellite observations of ice surface elevation changes have given researchers new insights into how subglacial water is stored and transported. Localized uplift and settling of the ice surface implies that lakes exist beneath the ice sheet that are being filled and drained on relatively short time scales. %At the base of an ice sheet water can be transported through a variety of drainage networks or stored in subglacial lakes. Here, a numerical investigation of the mechanisms of transport and storage of subglacial water and the associated time scales is presented. Experiments are carried out using a finite element model of coupled ice and water flow. The first experiment seeks to understand the relationship between the depth of a basal depression and the area over which the feature affects basal water flow. It is found that as the perturbation to a topographic depression's depth is increased, water is rerouted in response to the perturbation. Additionally it is found that the relationship between perturbation depth and the extent upstream to which its effects reach is nonlinear. The second experiment examines how the aspect ratio of bed features (prolate, oblate, or equidimensional) influences basal water flow. It is found that the systems that develop and their interactions are mediated by both the topography and the feedbacks taken into account by the coupling of the systems in the model. Features oriented parallel to ice and water flow are associated with distributed fan systems that develop branches which migrate laterally across the domain and interact with one another on monthly and yearly timescales. Laterally oriented features develop laterally extensive ponds. As the ratio of longitudinal to lateral dimension of the topography is increased, a combination of these two water distributions is seen. Title: Investigations into the Regional and Local Timescale Variations of Subglacial Drainage Networks Author: Hiester, Justin Year: 2013 Subglacial water plays an important role in the regulation of an ice sheet's mass balance. It may be the dominant control on the velocities of ice streams and outlet glaciers on scales of months to millennia. Recent satellite observations of ice surface elevation changes have given researchers new insights into how subglacial water is stored and transported. Localized uplift and settling of the ice surface implies that lakes exist beneath the ice sheet that are being filled and drained on relatively short time scales. %At the base of an ice sheet water can be transported through a variety of drainage networks or stored in subglacial lakes. Here, a numerical investigation of the mechanisms of transport and storage of subglacial water and the associated time scales is presented. Experiments are carried out using a finite element model of coupled ice and water flow. The first experiment seeks to understand the relationship between the depth of a basal depression and the area over which the feature affects basal water flow. It is found that as the perturbation to a topographic depression's depth is increased, water is rerouted in response to the perturbation. Additionally it is found that the relationship between perturbation depth and the extent upstream to which its effects reach is nonlinear. The second experiment examines how the aspect ratio of bed features (prolate, oblate, or equidimensional) influences basal water flow. It is found that the systems that develop and their interactions are mediated by both the topography and the feedbacks taken into account by the coupling of the systems in the model. Features oriented parallel to ice and water flow are associated with distributed fan systems that develop branches which migrate laterally across the domain and interact with one another on monthly and yearly timescales. Laterally oriented features develop laterally extensive ponds. As the ratio of longitudinal to lateral dimension of the topography is increased, a combination of these two water distributions is seen. Close

• 2. [Article] Analysis and numerical simulation of the ground water system at the Bonneville navigation lock site, Oregon

  As part of the new navigation lock for Bonneville Dam a new water source for the Bonneville Fish Hatchery must be supplied. The hatchery is located on the Oregon side of the Columbia River downstream of ...

  Citation × Citation Citation Abstract Copy Title: Analysis and numerical simulation of the ground water system at the Bonneville navigation lock site, Oregon Author: Baron, Dirk Year: 1990 As part of the new navigation lock for Bonneville Dam a new water source for the Bonneville Fish Hatchery must be supplied. The hatchery is located on the Oregon side of the Columbia River downstream of the dam. It requires large quantities of water free from chemical and biological contamination. In addition, the water has to be in a narrow temperature range. Currently the fish hatchery receives its water from a well field that is located on the alluvial terrace downstream of Bonneville Dam. The well field lies in the proposed approach channel for the new lock and has to be abandoned during construction of the lock. For the continued water supply of the hatchery, a new well field will be developed north of the approach channel. Early in the planning phase for the new lock, concerns were raised about the potential impact of the relocation of the well field and the excavation of the new approach channel on the hatchery. To assess these concerns and to assure a continuous water supply during and after construction, a hydrogeologic investigation was initiated. Within the framework of the investigation this study focuses on the analysis of pumping test data and the development of a three-dimensional ground water flow model for the site. Title: Analysis and numerical simulation of the ground water system at the Bonneville navigation lock site, Oregon Author: Baron, Dirk Year: 1990 As part of the new navigation lock for Bonneville Dam a new water source for the Bonneville Fish Hatchery must be supplied. The hatchery is located on the Oregon side of the Columbia River downstream of the dam. It requires large quantities of water free from chemical and biological contamination. In addition, the water has to be in a narrow temperature range. Currently the fish hatchery receives its water from a well field that is located on the alluvial terrace downstream of Bonneville Dam. The well field lies in the proposed approach channel for the new lock and has to be abandoned during construction of the lock. For the continued water supply of the hatchery, a new well field will be developed north of the approach channel. Early in the planning phase for the new lock, concerns were raised about the potential impact of the relocation of the well field and the excavation of the new approach channel on the hatchery. To assess these concerns and to assure a continuous water supply during and after construction, a hydrogeologic investigation was initiated. Within the framework of the investigation this study focuses on the analysis of pumping test data and the development of a three-dimensional ground water flow model for the site. Close

• 3. [Article] Water quality effects of hyporheic processing

  "PB2000-107420."

  Citation × Citation Citation Abstract Copy Title: Water quality effects of hyporheic processing Author: Wigington, P.J., Landers, Dixon, Fernald, Alexander "PB2000-107420." Title: Water quality effects of hyporheic processing Author: Wigington, P.J., Landers, Dixon, Fernald, Alexander "PB2000-107420." Close

• 4. [Article] Upper Spokane River Model: Boundary Conditions and Model Setup, 2001

  The Washington Department of Ecology is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). The goals of this modeling effort ...

  Citation × Citation Citation Abstract Copy Title: Upper Spokane River Model: Boundary Conditions and Model Setup, 2001 Author: Slominski, Spencer, Annear, Robert Leslie, Berger, Chris, Wells, Scott A. Year: 2002 The Washington Department of Ecology is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). The goals of this modeling effort are to: • Gather data to construct a computer simulation model of the Spokane River system including Long Lake Reservoir and the pools behind Nine Mile dam, Upper Falls dam and Upriver dam for 2001 based on the calibration conducted for 1991 and 2000 data sets, (Annear et al, 2001). • Ensure that the model accurately represents the system hydrodynamics and water quality (flow, temperature, dissolved oxygen and nutrient dynamics) for the three simulation years A hydrodynamic and water quality model, CE-QUAL-W2 Version 3 (Wells, 1997), is being applied to model the Spokane River system. CE-QUAL-W2 is a two dimensional (longitudinal-vertical), laterally averaged, hydrodynamic and water quality model that has been under development by the Corps of Engineers Waterways Experiment Station (Cole and Wells, 2000). In order to model the system, the following data were required: • Spokane River flow, water level and water quality data at the upstream system boundary (the State of Idaho boundary) • Tributary inflows and water quality • Meteorological conditions • Bathymetry of the Spokane River, the dam pools along the river, and Long Lake Reservoir • Point source (wastewater treatment plants, WWTPs) inflows and water quality characteristics Data have been primarily collected from 1991 to 1992, during 2000, and more recently during 2001. This report summarizes the 2001 data used in the modeling effort to expand the model calibration period. Title: Upper Spokane River Model: Boundary Conditions and Model Setup, 2001 Author: Slominski, Spencer, Annear, Robert Leslie, Berger, Chris, Wells, Scott A. Year: 2002 The Washington Department of Ecology is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). The goals of this modeling effort are to: • Gather data to construct a computer simulation model of the Spokane River system including Long Lake Reservoir and the pools behind Nine Mile dam, Upper Falls dam and Upriver dam for 2001 based on the calibration conducted for 1991 and 2000 data sets, (Annear et al, 2001). • Ensure that the model accurately represents the system hydrodynamics and water quality (flow, temperature, dissolved oxygen and nutrient dynamics) for the three simulation years A hydrodynamic and water quality model, CE-QUAL-W2 Version 3 (Wells, 1997), is being applied to model the Spokane River system. CE-QUAL-W2 is a two dimensional (longitudinal-vertical), laterally averaged, hydrodynamic and water quality model that has been under development by the Corps of Engineers Waterways Experiment Station (Cole and Wells, 2000). In order to model the system, the following data were required: • Spokane River flow, water level and water quality data at the upstream system boundary (the State of Idaho boundary) • Tributary inflows and water quality • Meteorological conditions • Bathymetry of the Spokane River, the dam pools along the river, and Long Lake Reservoir • Point source (wastewater treatment plants, WWTPs) inflows and water quality characteristics Data have been primarily collected from 1991 to 1992, during 2000, and more recently during 2001. This report summarizes the 2001 data used in the modeling effort to expand the model calibration period. Close

• 5. [Article] Upper Spokane River Model: Boundary Conditions and Model Setup, 1991 and 2000

  The Washington Department of Ecology is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). The goals of this modeling effort ...

  Citation × Citation Citation Abstract Copy Title: Upper Spokane River Model: Boundary Conditions and Model Setup, 1991 and 2000 Author: Annear, Robert Leslie, Berger, Chris, Wells, Scott A. Year: 2001 The Washington Department of Ecology is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). The goals of this modeling effort are to: • Gather data to construct a computer simulation model of the Spokane River system including Long Lake Reservoir and the pools behind Nine Mile dam, Upper Falls dam and Upriver dam • Ensure that the model accurately represents the system hydrodynamics and water quality (flow, temperature, dissolved oxygen and nutrient dynamics) A hydrodynamic and water quality model, CE-QUAL-W2 Version 3 (Wells, 1997), is being applied to model the Spokane River system. CE-QUAL-W2 is a two dimensional (longitudinal-vertical), laterally averaged, hydrodynamic and water quality model that has been under development by the Corps of Engineers Waterways Experiments Station (Cole and Wells, 2000). In order to model the system, the following data were required: • Spokane River flow, water level and water quality data at the upstream system boundary (the State of Idaho boundary) • Tributary inflows and water quality • Meteorological conditions • Bathymetry of the Spokane River, the dam pools along the river, and Long Lake Reservoir • Point source (wastewater treatment plants, WWTPs) inflows and water quality characteristics Data have been primarily collected from 1991 to 1992 and again during 2000. This report summarizes the data used in the modeling effort. Title: Upper Spokane River Model: Boundary Conditions and Model Setup, 1991 and 2000 Author: Annear, Robert Leslie, Berger, Chris, Wells, Scott A. Year: 2001 The Washington Department of Ecology is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). The goals of this modeling effort are to: • Gather data to construct a computer simulation model of the Spokane River system including Long Lake Reservoir and the pools behind Nine Mile dam, Upper Falls dam and Upriver dam • Ensure that the model accurately represents the system hydrodynamics and water quality (flow, temperature, dissolved oxygen and nutrient dynamics) A hydrodynamic and water quality model, CE-QUAL-W2 Version 3 (Wells, 1997), is being applied to model the Spokane River system. CE-QUAL-W2 is a two dimensional (longitudinal-vertical), laterally averaged, hydrodynamic and water quality model that has been under development by the Corps of Engineers Waterways Experiments Station (Cole and Wells, 2000). In order to model the system, the following data were required: • Spokane River flow, water level and water quality data at the upstream system boundary (the State of Idaho boundary) • Tributary inflows and water quality • Meteorological conditions • Bathymetry of the Spokane River, the dam pools along the river, and Long Lake Reservoir • Point source (wastewater treatment plants, WWTPs) inflows and water quality characteristics Data have been primarily collected from 1991 to 1992 and again during 2000. This report summarizes the data used in the modeling effort. Close

• 6. [Article] Upper Spokane River Model: Model Calibration, 1991 and 2000

  The Washington Department of Ecology is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). The goals of this modeling effort ...

  Citation × Citation Citation Abstract Copy Title: Upper Spokane River Model: Model Calibration, 1991 and 2000 Author: Berger, Chris, Annear, Robert Leslie, Wells, Scott A. Year: 2002 The Washington Department of Ecology is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). The goals of this modeling effort are to: • Gather data to construct a computer simulation model of the Spokane River system including Long Lake Reservoir and the pools behind Nine Mile dam, Upper Falls dam and Upriver dam. • Ensure that the model accurately represents the system hydrodynamics and water quality (flow, temperature, dissolved oxygen and nutrient dynamics) This report evaluates the model calibration and discusses issues relative to that calibration effort. The calibration effort focused on model predictions of hydrodynamics (flow and water level), temperature, and eutrophication model parameters (such as nutrients, algae, dissolved oxygen, organic matter, coliform). The model calibration periods were from February 1, 1991 to October 31, 1991 and from January 1, 2000 to October 31, 2000. Title: Upper Spokane River Model: Model Calibration, 1991 and 2000 Author: Berger, Chris, Annear, Robert Leslie, Wells, Scott A. Year: 2002 The Washington Department of Ecology is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). The goals of this modeling effort are to: • Gather data to construct a computer simulation model of the Spokane River system including Long Lake Reservoir and the pools behind Nine Mile dam, Upper Falls dam and Upriver dam. • Ensure that the model accurately represents the system hydrodynamics and water quality (flow, temperature, dissolved oxygen and nutrient dynamics) This report evaluates the model calibration and discusses issues relative to that calibration effort. The calibration effort focused on model predictions of hydrodynamics (flow and water level), temperature, and eutrophication model parameters (such as nutrients, algae, dissolved oxygen, organic matter, coliform). The model calibration periods were from February 1, 1991 to October 31, 1991 and from January 1, 2000 to October 31, 2000. Close

• 7. [Article] Idaho Pend Oreille River Model: Model Development and Calibration

  The objectives of this project were to: • Develop a hydrodynamic and temperature model of Pend Oreille River using CE-QUAL-W2 Version 3.2 • Calibrate the CE-QUAL-W2 model to field data collected during ...

  Citation × Citation Citation Abstract Copy Title: Idaho Pend Oreille River Model: Model Development and Calibration Author: Annear, Robert Leslie, Berger, Chris, Wells, Scott A. Year: 2006 The objectives of this project were to: • Develop a hydrodynamic and temperature model of Pend Oreille River using CE-QUAL-W2 Version 3.2 • Calibrate the CE-QUAL-W2 model to field data collected during 2004 and 2005 using the following water quality variables: flow, water surface elevation, and velocity temperature o dissolved oxygen nutrients (NO3-N+NO2-N, NH4-N, PO4-P) algae – chlorophyll a BOD5 and dissolved organic matter and particulate organic matter compartments (both labile and refractory) for the organic matter cycling with algae periphyton The model chosen for development was CE-QUAL-W2 Version 3.2 (Cole and Wells, 2004). This is a two-dimensional unsteady hydrodynamic and water quality model that includes typical eutrophication constituents (algae, nutrients, temperature, organic matter, dissolved oxygen, pH). Portland State University’s Water Quality Research Group is a center for development of this modeling tool (see http://www.cee.pdx.edu/w2). The model simulation was run from January 1st, 2004 to September 25th, 2005. The calibration period focused on the summers during each year when water quality data were obtained. Title: Idaho Pend Oreille River Model: Model Development and Calibration Author: Annear, Robert Leslie, Berger, Chris, Wells, Scott A. Year: 2006 The objectives of this project were to: • Develop a hydrodynamic and temperature model of Pend Oreille River using CE-QUAL-W2 Version 3.2 • Calibrate the CE-QUAL-W2 model to field data collected during 2004 and 2005 using the following water quality variables: flow, water surface elevation, and velocity temperature o dissolved oxygen nutrients (NO3-N+NO2-N, NH4-N, PO4-P) algae – chlorophyll a BOD5 and dissolved organic matter and particulate organic matter compartments (both labile and refractory) for the organic matter cycling with algae periphyton The model chosen for development was CE-QUAL-W2 Version 3.2 (Cole and Wells, 2004). This is a two-dimensional unsteady hydrodynamic and water quality model that includes typical eutrophication constituents (algae, nutrients, temperature, organic matter, dissolved oxygen, pH). Portland State University’s Water Quality Research Group is a center for development of this modeling tool (see http://www.cee.pdx.edu/w2). The model simulation was run from January 1st, 2004 to September 25th, 2005. The calibration period focused on the summers during each year when water quality data were obtained. Close

• 8. [Article] Hydrologic and Land Cover Effects on Sources and Fate of In-Stream Fluorescent Dissolved Organic Matter

  Dissolved organic matter (DOM) is a critical component of the carbon cycle linking terrestrial and aquatic ecosystems. Although many factors influence DOM fluxes and quality in rivers, controls on DOM ...

  Citation × Citation Citation Abstract Copy Title: Hydrologic and Land Cover Effects on Sources and Fate of In-Stream Fluorescent Dissolved Organic Matter Author: Lee, Baek Soo P. Dissolved organic matter (DOM) is a critical component of the carbon cycle linking terrestrial and aquatic ecosystems. Although many factors influence DOM fluxes and quality in rivers, controls on DOM compositions in catchments of the western U.S. are poorly understood. UV and fluorescent spectroscopy is a simpler, faster, and less expensive DOM fingerprinting technique compared to techniques, such as nuclear magnetic resonance (NMR) spectroscopy or wet chemical fractionation, and could be useful for characterizing complex DOM chemistry. However, only 1 % of DOM is estimated to be fluorescent, and the utility of UV and fluorescent spectroscopy for DOM characterization needs to be further investigated. This dissertation applied UV and fluorescent spectroscopy to examine hydrologic and land cover controls on DOM chemistry in streams of 45 catchments in the forested headwaters and a mixed landscape of the Willamette River Basin, Oregon, based on two years of monitoring. This dissertation contributes three major findings. First, freezing of water alters DOM chemistry by preferentially precipitating aromatic DOM. Second, UV and fluorescent spectroscopy was able to discriminate DOM delivered from highly processed, proteinrich deep subsurface sources during dry seasons especially in forested headwater streams of the H. J. Andrews Experimental Forest (HJA), where nitrogen inputs are very low. In addition, fluorescent DOM chemistry differed among watersheds with varying forest management history. Third, although fluorescent DOM in a headwater forested system differed among land use history, fluorescent DOM composition did not vary among streams draining a well-mixed landscape of urban, pasture/hay, forest, and agricultural land cover types in the central Willamette River Basin, where nitrogen inputs to streams are relatively high. Dissolved organic carbon (DOC) concentration decreased and the fluorescent index indicated an increase in terrestrial sources of DOM from small (1st and 2nd order) to large (4th to 6th order) streams. A protein-like DOM component that was detected in the headwater forested study site (HJA) was not detected in stream samples from the middle basin study site. These findings indicate that in-stream respiration, fueled by nutrient additions from agriculture runoff, consumes bioavailable, labile DOM (proteins) preferentially relative to more recalcitrant, terrestrial sources of DOM along water flow paths from headwater streams to major rivers. This study shows the clear applicability of the fluorescent characterization of DOM in identifying hydrologic and landscape controls as well as varying DOM chemistry and functions throughout watershed ecosystems. Title: Hydrologic and Land Cover Effects on Sources and Fate of In-Stream Fluorescent Dissolved Organic Matter Author: Lee, Baek Soo P. Dissolved organic matter (DOM) is a critical component of the carbon cycle linking terrestrial and aquatic ecosystems. Although many factors influence DOM fluxes and quality in rivers, controls on DOM compositions in catchments of the western U.S. are poorly understood. UV and fluorescent spectroscopy is a simpler, faster, and less expensive DOM fingerprinting technique compared to techniques, such as nuclear magnetic resonance (NMR) spectroscopy or wet chemical fractionation, and could be useful for characterizing complex DOM chemistry. However, only 1 % of DOM is estimated to be fluorescent, and the utility of UV and fluorescent spectroscopy for DOM characterization needs to be further investigated. This dissertation applied UV and fluorescent spectroscopy to examine hydrologic and land cover controls on DOM chemistry in streams of 45 catchments in the forested headwaters and a mixed landscape of the Willamette River Basin, Oregon, based on two years of monitoring. This dissertation contributes three major findings. First, freezing of water alters DOM chemistry by preferentially precipitating aromatic DOM. Second, UV and fluorescent spectroscopy was able to discriminate DOM delivered from highly processed, proteinrich deep subsurface sources during dry seasons especially in forested headwater streams of the H. J. Andrews Experimental Forest (HJA), where nitrogen inputs are very low. In addition, fluorescent DOM chemistry differed among watersheds with varying forest management history. Third, although fluorescent DOM in a headwater forested system differed among land use history, fluorescent DOM composition did not vary among streams draining a well-mixed landscape of urban, pasture/hay, forest, and agricultural land cover types in the central Willamette River Basin, where nitrogen inputs to streams are relatively high. Dissolved organic carbon (DOC) concentration decreased and the fluorescent index indicated an increase in terrestrial sources of DOM from small (1st and 2nd order) to large (4th to 6th order) streams. A protein-like DOM component that was detected in the headwater forested study site (HJA) was not detected in stream samples from the middle basin study site. These findings indicate that in-stream respiration, fueled by nutrient additions from agriculture runoff, consumes bioavailable, labile DOM (proteins) preferentially relative to more recalcitrant, terrestrial sources of DOM along water flow paths from headwater streams to major rivers. This study shows the clear applicability of the fluorescent characterization of DOM in identifying hydrologic and landscape controls as well as varying DOM chemistry and functions throughout watershed ecosystems. Close

• 9. [Article] Inter-relationships of vegetation, hydrology and micro-climate in a young, Douglas-fir forest

  The links between forests, streamflow, and climate are poorly understood. Despite hundreds of studies over the past 60 years, fundamental questions of forests' effects on the hydrologic cycle remain unanswered. ...

  Citation × Citation Citation Abstract Copy Title: Inter-relationships of vegetation, hydrology and micro-climate in a young, Douglas-fir forest Author: Barnard, Holly Rene The links between forests, streamflow, and climate are poorly understood. Despite hundreds of studies over the past 60 years, fundamental questions of forests' effects on the hydrologic cycle remain unanswered. The hydrological cycle involves mutually-dependent biological and physical processes that operate at multiple scales of time and space, and this principle is the foundation for research in ecohydrology. The objective of this research was to determine how vegetation processes (especially transpiration) affect subsurface water flow dynamics in hillslopes, and conversely how soil moisture and environmental variables affect vegetation function. This dissertation used multiple approaches to mechanistically assess the inter-relationships between vegetation water use, hydrology, and climate. I found that transpiration on hillslopes played an important role in diel variation in subsurface discharge in headwater catchment. However, the amount of influence transpiration had on discharge was strongly dependent upon soil moisture properties. In addition, plot-scale transpiration across a steep topographic gradient could not be predicted from measured variations in environmental variables alone. Heterogeneity in biophysical drivers, edaphic properties and whole tree conductance controlled plot scale transpiration. Last, I applied a dual isotope (¹³C and ¹⁸O) approach to infer physiological response of trees to changing environmental conditions. I found that stable isotopes of oxygen were directly related to stomatal conductance and inversely related to relative humidity; however, the relationship with relative humidity more apparent. The correlation of stable isotopes in tree rings with environmental variables can be particularly useful for assessing the impacts of environmental change on vegetation over short time series. Results demonstrated that the physiological interpretation of stable isotope in tree rings continues to be challenging in uncontrolled environments. This work represents one step forward in elucidating the linkages between vegetation processes, hydrology, and climate. Title: Inter-relationships of vegetation, hydrology and micro-climate in a young, Douglas-fir forest Author: Barnard, Holly Rene The links between forests, streamflow, and climate are poorly understood. Despite hundreds of studies over the past 60 years, fundamental questions of forests' effects on the hydrologic cycle remain unanswered. The hydrological cycle involves mutually-dependent biological and physical processes that operate at multiple scales of time and space, and this principle is the foundation for research in ecohydrology. The objective of this research was to determine how vegetation processes (especially transpiration) affect subsurface water flow dynamics in hillslopes, and conversely how soil moisture and environmental variables affect vegetation function. This dissertation used multiple approaches to mechanistically assess the inter-relationships between vegetation water use, hydrology, and climate. I found that transpiration on hillslopes played an important role in diel variation in subsurface discharge in headwater catchment. However, the amount of influence transpiration had on discharge was strongly dependent upon soil moisture properties. In addition, plot-scale transpiration across a steep topographic gradient could not be predicted from measured variations in environmental variables alone. Heterogeneity in biophysical drivers, edaphic properties and whole tree conductance controlled plot scale transpiration. Last, I applied a dual isotope (¹³C and ¹⁸O) approach to infer physiological response of trees to changing environmental conditions. I found that stable isotopes of oxygen were directly related to stomatal conductance and inversely related to relative humidity; however, the relationship with relative humidity more apparent. The correlation of stable isotopes in tree rings with environmental variables can be particularly useful for assessing the impacts of environmental change on vegetation over short time series. Results demonstrated that the physiological interpretation of stable isotope in tree rings continues to be challenging in uncontrolled environments. This work represents one step forward in elucidating the linkages between vegetation processes, hydrology, and climate. Close

• 10. [Article] Flow processes in the dry regime : the effect on capillary barrier performance

  Engineered capillary barriers typically consist of two layers of granular materials designed so that the contrast in sediment hydrologic properties and sloping interface retains infiltrating water in the ...

  Citation × Citation Citation Abstract Copy Title: Flow processes in the dry regime : the effect on capillary barrier performance Author: Jansik, Danielle P. Engineered capillary barriers typically consist of two layers of granular materials designed so that the contrast in sediment hydrologic properties and sloping interface retains infiltrating water in the upper layer. We report here on the results of two bench-top capillary barrier experiments, and associated modeling. These experiments were conducted to better understand the behavior of capillary barriers in particular with respect to an engineered barrier system proposed at the potential high-level nuclear waste site at Yucca Mountain, Nevada, where different engineered barriers have been under consideration throughout the site development process (Carter and Pigford 2005; Tidwell et al. 2003). We measured hydrologic parameters for both coarse materials using standard methods and found that the two materials had similar hydrologic properties despite being morphologically different (round, uniform vs. angular, non-uniform). The rounded sand provided a better functioning capillary barrier than the angular sand, but neither experiment could be characterized as a perfectly working capillary barrier. In both cases, more than 93% of the infiltrating water was successfully diverted from the lower layer, but infiltration into the underlying layer was observed in both systems. Our experimental results show that capillary barriers designed based on standard hydrologic property measurements may result in invalid prediction of the system behavior. Moreover, our numerical simulations of these experiments show that the predicted capillary barrier performance was highly sensitive to physically realistic variability in model hydrologic parameter values. Based on this work, we believe that other non-continuum processes such as vapor diffusion and film flow contribute to the observed phenomena and are important aspects to consider with respect to capillary barrier design, as well as dry vadose zone processes in general. By applying a theoretical film flow equation representative of sediment surface geometries we were able to show that infiltration into the underlying sediment layer can be dominated by water film flow, a characteristic that is typically not considered in mainstream numerical models. Title: Flow processes in the dry regime : the effect on capillary barrier performance Author: Jansik, Danielle P. Engineered capillary barriers typically consist of two layers of granular materials designed so that the contrast in sediment hydrologic properties and sloping interface retains infiltrating water in the upper layer. We report here on the results of two bench-top capillary barrier experiments, and associated modeling. These experiments were conducted to better understand the behavior of capillary barriers in particular with respect to an engineered barrier system proposed at the potential high-level nuclear waste site at Yucca Mountain, Nevada, where different engineered barriers have been under consideration throughout the site development process (Carter and Pigford 2005; Tidwell et al. 2003). We measured hydrologic parameters for both coarse materials using standard methods and found that the two materials had similar hydrologic properties despite being morphologically different (round, uniform vs. angular, non-uniform). The rounded sand provided a better functioning capillary barrier than the angular sand, but neither experiment could be characterized as a perfectly working capillary barrier. In both cases, more than 93% of the infiltrating water was successfully diverted from the lower layer, but infiltration into the underlying layer was observed in both systems. Our experimental results show that capillary barriers designed based on standard hydrologic property measurements may result in invalid prediction of the system behavior. Moreover, our numerical simulations of these experiments show that the predicted capillary barrier performance was highly sensitive to physically realistic variability in model hydrologic parameter values. Based on this work, we believe that other non-continuum processes such as vapor diffusion and film flow contribute to the observed phenomena and are important aspects to consider with respect to capillary barrier design, as well as dry vadose zone processes in general. By applying a theoretical film flow equation representative of sediment surface geometries we were able to show that infiltration into the underlying sediment layer can be dominated by water film flow, a characteristic that is typically not considered in mainstream numerical models. Close

• 11. [Article] Lower Willamette River Model: Model Calibration

  Water Environment Services of Clackamas County is in the process of planning upgrades on several of its wastewater treatment plants (WWTPs) which discharge into the Lower Willamette River. The goals of ...

  Citation × Citation Citation Abstract Copy Title: Lower Willamette River Model: Model Calibration Author: Berger, Chris, Annear, Robert Leslie, Wells, Scott A. Year: 2001 Water Environment Services of Clackamas County is in the process of planning upgrades on several of its wastewater treatment plants (WWTPs) which discharge into the Lower Willamette River. The goals of the modeling effort were to: • Gather data to construct a computer simulation model of the Lower Willamette River system in order to evaluate the impact of the WWTP discharges on water quality • Ensure that the model accurately represents the system physics and chemistry (flow, temperature, dissolved oxygen and nutrient dynamics) by model calibration • Use the model to evaluate how to meet various future discharge scenarios for Water Environment Services of Clackamas County. This report evaluates the model calibration and discusses issues relative to that calibration effort. The calibration effort focused on model predictions of hydrodynamics (flow and water level), temperature, and eutrophication model parameters (such as nutrients, algae, dissolved oxygen, organic matter, coliform). Title: Lower Willamette River Model: Model Calibration Author: Berger, Chris, Annear, Robert Leslie, Wells, Scott A. Year: 2001 Water Environment Services of Clackamas County is in the process of planning upgrades on several of its wastewater treatment plants (WWTPs) which discharge into the Lower Willamette River. The goals of the modeling effort were to: • Gather data to construct a computer simulation model of the Lower Willamette River system in order to evaluate the impact of the WWTP discharges on water quality • Ensure that the model accurately represents the system physics and chemistry (flow, temperature, dissolved oxygen and nutrient dynamics) by model calibration • Use the model to evaluate how to meet various future discharge scenarios for Water Environment Services of Clackamas County. This report evaluates the model calibration and discusses issues relative to that calibration effort. The calibration effort focused on model predictions of hydrodynamics (flow and water level), temperature, and eutrophication model parameters (such as nutrients, algae, dissolved oxygen, organic matter, coliform). Close

• 12. [Article] Lower Willamette River Model: Boundary Conditions and Model Setup

  Water Environment Services of Clackamas County is in the process of planning upgrades on several of its sewage treatment plants which discharge into the Lower Willamette River. The goals of the modeling ...

  Citation × Citation Citation Abstract Copy Title: Lower Willamette River Model: Boundary Conditions and Model Setup Author: Rodriguez, Herman G., Annear, Robert Leslie, Wells, Scott A., Berger, Chris Year: 2001 Water Environment Services of Clackamas County is in the process of planning upgrades on several of its sewage treatment plants which discharge into the Lower Willamette River. The goals of the modeling effort are to: • Gather data to construct a computer simulation model of the Lower Willamette River system including part of the Lower Columbia River and the Willamette River above the Oregon City Falls; Because of the tidal influence in the Lower Willamette River, portions of the Columbia River that might affect the Lower Willamette River water quality were also modeled. Also, a section of the Willamette River above the head of tide, the Oregon City Falls, was modeled because of the lack of good boundary condition data at the Falls. • Ensure that the model accurately represents the system physics and chemistry (flow, temperature, dissolved oxygen and nutrient dynamics); • Use the model to evaluate how to meet various future discharge scenarios for the sewage district. A hydrodynamic and water quality model, CE-QUAL-W2 Version 3 (Wells, 1997), is being applied to model the Willamette-Columbia system. CE-QUAL-W2 is a two dimensional (longitudinal-vertical), laterally averaged, hydrodynamic and water quality model that has been under development by the Corps of Engineers Waterways Experiments Station (Cole and Wells, 2000). In order to model the system, the following data were required: • Willamette and Columbia River flow, water level and water quality data • Tributary inflows and water quality • Meteorological conditions • Bathymetry of the Columbia and Willamette Rivers and several side channels • Point source inflows and water quality characteristics Many local, state and federal agencies have been collecting data in the Lower Willamette and Columbia Rivers. This report summarizes data used in the modeling effort. Title: Lower Willamette River Model: Boundary Conditions and Model Setup Author: Rodriguez, Herman G., Annear, Robert Leslie, Wells, Scott A., Berger, Chris Year: 2001 Water Environment Services of Clackamas County is in the process of planning upgrades on several of its sewage treatment plants which discharge into the Lower Willamette River. The goals of the modeling effort are to: • Gather data to construct a computer simulation model of the Lower Willamette River system including part of the Lower Columbia River and the Willamette River above the Oregon City Falls; Because of the tidal influence in the Lower Willamette River, portions of the Columbia River that might affect the Lower Willamette River water quality were also modeled. Also, a section of the Willamette River above the head of tide, the Oregon City Falls, was modeled because of the lack of good boundary condition data at the Falls. • Ensure that the model accurately represents the system physics and chemistry (flow, temperature, dissolved oxygen and nutrient dynamics); • Use the model to evaluate how to meet various future discharge scenarios for the sewage district. A hydrodynamic and water quality model, CE-QUAL-W2 Version 3 (Wells, 1997), is being applied to model the Willamette-Columbia system. CE-QUAL-W2 is a two dimensional (longitudinal-vertical), laterally averaged, hydrodynamic and water quality model that has been under development by the Corps of Engineers Waterways Experiments Station (Cole and Wells, 2000). In order to model the system, the following data were required: • Willamette and Columbia River flow, water level and water quality data • Tributary inflows and water quality • Meteorological conditions • Bathymetry of the Columbia and Willamette Rivers and several side channels • Point source inflows and water quality characteristics Many local, state and federal agencies have been collecting data in the Lower Willamette and Columbia Rivers. This report summarizes data used in the modeling effort. Close

• 13. [Article] Modeling Macrophytes of the Columbia Slough, Oregon

  The Columbia Slough is a tidally influenced freshwater system of wetlands, channels, and lakes located within the Portland, Oregon metropolitan area at the confluence of the Willamette and Columbia Rivers. ...

  Citation × Citation Citation Abstract Copy Title: Modeling Macrophytes of the Columbia Slough, Oregon Author: Berger, Chris, Wells, Scott A. Year: 1999 The Columbia Slough is a tidally influenced freshwater system of wetlands, channels, and lakes located within the Portland, Oregon metropolitan area at the confluence of the Willamette and Columbia Rivers. It is a eutrophic water body susceptible to algae blooms and crashes and periods of high pH which violate water quality standards. High nutrient loads from groundwater principally controls algae productivity. Past structural changes to the Columbia Slough have included filling of wetlands and lakes and the construction of levees, dikes, culverts and irrigation channels. These changes have altered the natural flow dynamics creating an environment more conducive to eutrophication. A hydrodynamic and water quality model was used to evaluate management alternatives to improve water quality in the system. The model was developed using the Corps of Engineers two-dimensional, laterally averaged, dynamic water quality model, CE-QUAL-W2. CE-QUAL-W2 consists of directly coupled hydrodynamic and water quality transport. Recently, a management strategy of flow augmentation using groundwater coupled with shorter in-pool detention times has reduced algae growth. However, the resulting increase in water clarity has created an environment favorable to the growth of aquatic plants. The aquatic plants, or macrophytes, have increased water levels and detention time by increasing channel friction and blockage. Accurate predictions of hydrodynamics were essential for evaluating the water quality impact of flow management strategies. Macrophytes and epiphyton affect nutrient cycling by removing nutrients from the water column and sediment. To help evaluate the study of new management alternatives, the Columbia Slough model was expanded to simulate the water quality and hydrodynamic effects of macrophytes and epiphyton. Title: Modeling Macrophytes of the Columbia Slough, Oregon Author: Berger, Chris, Wells, Scott A. Year: 1999 The Columbia Slough is a tidally influenced freshwater system of wetlands, channels, and lakes located within the Portland, Oregon metropolitan area at the confluence of the Willamette and Columbia Rivers. It is a eutrophic water body susceptible to algae blooms and crashes and periods of high pH which violate water quality standards. High nutrient loads from groundwater principally controls algae productivity. Past structural changes to the Columbia Slough have included filling of wetlands and lakes and the construction of levees, dikes, culverts and irrigation channels. These changes have altered the natural flow dynamics creating an environment more conducive to eutrophication. A hydrodynamic and water quality model was used to evaluate management alternatives to improve water quality in the system. The model was developed using the Corps of Engineers two-dimensional, laterally averaged, dynamic water quality model, CE-QUAL-W2. CE-QUAL-W2 consists of directly coupled hydrodynamic and water quality transport. Recently, a management strategy of flow augmentation using groundwater coupled with shorter in-pool detention times has reduced algae growth. However, the resulting increase in water clarity has created an environment favorable to the growth of aquatic plants. The aquatic plants, or macrophytes, have increased water levels and detention time by increasing channel friction and blockage. Accurate predictions of hydrodynamics were essential for evaluating the water quality impact of flow management strategies. Macrophytes and epiphyton affect nutrient cycling by removing nutrients from the water column and sediment. To help evaluate the study of new management alternatives, the Columbia Slough model was expanded to simulate the water quality and hydrodynamic effects of macrophytes and epiphyton. Close

• 14. [Article] Upper Spokane River Model in Idaho: Boundary Conditions and Model Setup for 2001

  The Spokane River in Idaho originates in Coeur d’Alene Lake (Figure 1 and Figure 2). The section of the Spokane River from Coeur d’Alene Lake to the Washington state line is the subject of a water quality ...

  Citation × Citation Citation Abstract Copy Title: Upper Spokane River Model in Idaho: Boundary Conditions and Model Setup for 2001 Author: Wells, Scott A., Annear, Robert Leslie, Berger, Chris Year: 2003 The Spokane River in Idaho originates in Coeur d’Alene Lake (Figure 1 and Figure 2). The section of the Spokane River from Coeur d’Alene Lake to the Washington state line is the subject of a water quality study for the US Environmental Protection Agency. The objective of this study is to create a water quality and hydrodynamic model of the Spokane River in Idaho using CE-QUAL-W2 Version 3.1 (Cole and Wells, 2002). Since the Spokane River is water quality limited, a hydrodynamic and water quality model for the Spokane River in Washington was developed by Portland State University for the Corps of Engineers and the Washington Department of Ecology from the Idaho border to the outlet of Long Lake. An earlier study of the Spokane River was undertaken by Limno-Tech (2001a, 2001b) for the domain shown in Figure 3. Limno-Tech used an earlier version of CE-QUAL-W2, Version 2, for the Reservoir portion of the Spokane River from Post Falls Dam to Coeur d’Alene Lake and a steady-state EPA model, QUAL2E, for the riverine section from Post Falls Dam to the Idaho-Washington border. The steady-state QUAL2E model was not adequate to deal with flow and water quality dynamics. Hence, the riverine portion of the model and the reservoir portion were both upgraded to CE-QUAL-W2 Version 3.1. Because of the necessity of looking at the entire water basin, a model using CE-QUAL-W2 Version 3.1 of the Idaho portion of the Spokane River model was developed to assess water quality management strategies for the Idaho side of the Spokane River. Title: Upper Spokane River Model in Idaho: Boundary Conditions and Model Setup for 2001 Author: Wells, Scott A., Annear, Robert Leslie, Berger, Chris Year: 2003 The Spokane River in Idaho originates in Coeur d’Alene Lake (Figure 1 and Figure 2). The section of the Spokane River from Coeur d’Alene Lake to the Washington state line is the subject of a water quality study for the US Environmental Protection Agency. The objective of this study is to create a water quality and hydrodynamic model of the Spokane River in Idaho using CE-QUAL-W2 Version 3.1 (Cole and Wells, 2002). Since the Spokane River is water quality limited, a hydrodynamic and water quality model for the Spokane River in Washington was developed by Portland State University for the Corps of Engineers and the Washington Department of Ecology from the Idaho border to the outlet of Long Lake. An earlier study of the Spokane River was undertaken by Limno-Tech (2001a, 2001b) for the domain shown in Figure 3. Limno-Tech used an earlier version of CE-QUAL-W2, Version 2, for the Reservoir portion of the Spokane River from Post Falls Dam to Coeur d’Alene Lake and a steady-state EPA model, QUAL2E, for the riverine section from Post Falls Dam to the Idaho-Washington border. The steady-state QUAL2E model was not adequate to deal with flow and water quality dynamics. Hence, the riverine portion of the model and the reservoir portion were both upgraded to CE-QUAL-W2 Version 3.1. Because of the necessity of looking at the entire water basin, a model using CE-QUAL-W2 Version 3.1 of the Idaho portion of the Spokane River model was developed to assess water quality management strategies for the Idaho side of the Spokane River. Close

• 15. [Article] Modeling of Historic Columbia River Flood Impacts Based on Delft 3D Simulations

  Natural and anthropogenic processes over the past 150 years have altered the bathymetry of the Lower Columbia River (LCR) and have changed the long wave propagation of tides and floods. Possible causes ...

  Citation × Citation Citation Abstract Copy Title: Modeling of Historic Columbia River Flood Impacts Based on Delft 3D Simulations Author: Helaire, Lumas Terence Year: 2016 Natural and anthropogenic processes over the past 150 years have altered the bathymetry of the Lower Columbia River (LCR) and have changed the long wave propagation of tides and floods. Possible causes for the increase in tidal amplitudes (+7% in tidal range in Astoria) are decreases in river discharge, lengthening of the river channel due to the construction of jetties at the mouth, dredging and deepening of the shipping channel, and reduction of the tidal prism due to the filling and diking of tidal wetlands. In this study, changes in the characteristics of long waves are elucidated by developing two hydrodynamic models of the LCR which reflect historical and modern bathymetric conditions and forcing. The historic model simulates late 19th century conditions and is extensively validated using recently recovered tide records along the LCR (e.g., Astoria, 1853-1876) and river stage measurements (e.g., Portland, 1876-1964). Results suggest that water levels in Portland at low river discharge are up to 0.5-1.0m lower than in the past. However, historical water levels during a flood scenario based on the 1880 spring freshet are similar to modern water levels. Since tidal range in the modern scenario is persistently higher at all locations, the flood risk in many locations along the LCR has increased for the same boundary conditions. The results are explained by considering the governing equations of momentum and mass-conservation. At low river flow, greater depth leads to reduced frictional effects, producing amplified tidal range and tidal velocities but a decreased river slope (and lower Portland water levels). At high flow, the modern flood is confined by dikes and the loss of wetlands, which counteracts the effect of decreased friction. Nonetheless, the high friction of the historical wooded floodplain also confined the historical flood path. Hence, historical and modern flood heights are surprisingly similar, though scaling analysis suggests that the historical flood wave was more diffusive. Title: Modeling of Historic Columbia River Flood Impacts Based on Delft 3D Simulations Author: Helaire, Lumas Terence Year: 2016 Natural and anthropogenic processes over the past 150 years have altered the bathymetry of the Lower Columbia River (LCR) and have changed the long wave propagation of tides and floods. Possible causes for the increase in tidal amplitudes (+7% in tidal range in Astoria) are decreases in river discharge, lengthening of the river channel due to the construction of jetties at the mouth, dredging and deepening of the shipping channel, and reduction of the tidal prism due to the filling and diking of tidal wetlands. In this study, changes in the characteristics of long waves are elucidated by developing two hydrodynamic models of the LCR which reflect historical and modern bathymetric conditions and forcing. The historic model simulates late 19th century conditions and is extensively validated using recently recovered tide records along the LCR (e.g., Astoria, 1853-1876) and river stage measurements (e.g., Portland, 1876-1964). Results suggest that water levels in Portland at low river discharge are up to 0.5-1.0m lower than in the past. However, historical water levels during a flood scenario based on the 1880 spring freshet are similar to modern water levels. Since tidal range in the modern scenario is persistently higher at all locations, the flood risk in many locations along the LCR has increased for the same boundary conditions. The results are explained by considering the governing equations of momentum and mass-conservation. At low river flow, greater depth leads to reduced frictional effects, producing amplified tidal range and tidal velocities but a decreased river slope (and lower Portland water levels). At high flow, the modern flood is confined by dikes and the loss of wetlands, which counteracts the effect of decreased friction. Nonetheless, the high friction of the historical wooded floodplain also confined the historical flood path. Hence, historical and modern flood heights are surprisingly similar, though scaling analysis suggests that the historical flood wave was more diffusive. Close

• 16. [Article] Upper Spokane River Model: Model Calibration, 2001

  The Upper Spokane River system under consideration is located in the Northeastern part of Washington State and runs from the Stateline with Idaho, River mile (RM) 96.0, downstream to Long Lake dam at RM ...

  Citation × Citation Citation Abstract Copy Title: Upper Spokane River Model: Model Calibration, 2001 Author: Berger, Chris, Annear, Robert Leslie, Welle, Benjamin Year: 2003 The Upper Spokane River system under consideration is located in the Northeastern part of Washington State and runs from the Stateline with Idaho, River mile (RM) 96.0, downstream to Long Lake dam at RM 32.5. Figure 1 shows the river system and an outline the boundaries of the City of Spokane. The Washington Department of Ecology (Ecology) is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). As a result, Ecology and the Corps of Engineers funded a study to develop a water quality and hydrodynamic model of the Spokane River system for the years 1991 and 2000. Since the City of Spokane and other point dischargers to the Spokane River have taken considerable field data in the Spokane River system during 2001, the City of Spokane funded this study primarily to: • Continue the development of the Spokane River model for the year 2001, and • Ensure that the model retains its calibration for the year 2001 A hydrodynamic and water quality model, CE-QUAL-W2 Version 3 (Wells, 1997), was applied to the Spokane River system for the years 1991 and 2000. CE-QUAL-W2 is a two dimensional (longitudinalvertical), laterally averaged, hydrodynamic and water quality model that has been under development by the Corps of Engineers Waterways Experiments Station (Cole and Wells, 2000). This report evaluates the 2001 model calibration and discusses issues relative to that calibration effort. The calibration effort focused on model predictions of hydrodynamics (flow and water level), temperature, and eutrophication model parameters (such as nutrients, algae, dissolved oxygen, organic matter, coliform). The model calibration period was from March 15, 2001 to October 31, 2001. Title: Upper Spokane River Model: Model Calibration, 2001 Author: Berger, Chris, Annear, Robert Leslie, Welle, Benjamin Year: 2003 The Upper Spokane River system under consideration is located in the Northeastern part of Washington State and runs from the Stateline with Idaho, River mile (RM) 96.0, downstream to Long Lake dam at RM 32.5. Figure 1 shows the river system and an outline the boundaries of the City of Spokane. The Washington Department of Ecology (Ecology) is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). As a result, Ecology and the Corps of Engineers funded a study to develop a water quality and hydrodynamic model of the Spokane River system for the years 1991 and 2000. Since the City of Spokane and other point dischargers to the Spokane River have taken considerable field data in the Spokane River system during 2001, the City of Spokane funded this study primarily to: • Continue the development of the Spokane River model for the year 2001, and • Ensure that the model retains its calibration for the year 2001 A hydrodynamic and water quality model, CE-QUAL-W2 Version 3 (Wells, 1997), was applied to the Spokane River system for the years 1991 and 2000. CE-QUAL-W2 is a two dimensional (longitudinalvertical), laterally averaged, hydrodynamic and water quality model that has been under development by the Corps of Engineers Waterways Experiments Station (Cole and Wells, 2000). This report evaluates the 2001 model calibration and discusses issues relative to that calibration effort. The calibration effort focused on model predictions of hydrodynamics (flow and water level), temperature, and eutrophication model parameters (such as nutrients, algae, dissolved oxygen, organic matter, coliform). The model calibration period was from March 15, 2001 to October 31, 2001. Close

• 17. [Article] Upper Spokane River Model in Idaho: Boundary Conditions and Model Setup and Calibration for 2001 and 2004

  As a result of a Total Maximum Daily Load (TMDL) study of the Spokane River in Washington, a hydrodynamic and water quality model for the Spokane River was developed by Portland State University (PSU) ...

  Citation × Citation Citation Abstract Copy Title: Upper Spokane River Model in Idaho: Boundary Conditions and Model Setup and Calibration for 2001 and 2004 Author: Annear, Robert Leslie, Wells, Scott A., Berger, Chris Year: 2005 As a result of a Total Maximum Daily Load (TMDL) study of the Spokane River in Washington, a hydrodynamic and water quality model for the Spokane River was developed by Portland State University (PSU) for the Corps of Engineers and the Washington Department of Ecology from the Washington-Idaho state line to the outlet of Long Lake. An earlier study of the Spokane River was undertaken by Limno-Tech (2001a, 2001b) for the domain shown in Figure 3. Limno-Tech used an earlier version of CE-QUAL-W2, Version 2, for the Reservoir portion of the Spokane River from Post Falls Dam to Coeur d’Alene Lake and a steady-state EPA model, QUAL2E, for the riverine section from Post Falls Dam to the Idaho-Washington State Line. The steady-state QUAL2E model was not adequate to deal with flow and water quality dynamics. Hence, the riverine portion of the model and the reservoir portion were both upgraded to CE-QUAL-W2 Version 3.1. PSU developed the CE-QUAL-W2 model, but did not have adequate data for model calibration. The set-up of this model was described in the following report: * Wells et al. (2003) - Upper Spokane River Model in Idaho: Boundary Conditions and Model Setup for 2001 Because of the necessity of looking at the entire river basin, a model using CE-QUAL-W2 Version 3.1 of the Idaho portion of the Spokane River model was developed to assess water quality management strategies for the Idaho side of the Spokane River. The objective of this study was to use new field data from 2001 and 2004 to improve the model calibration for the Idaho portion of the Spokane River and reevaluate the work done by Wells et al. (2003). Title: Upper Spokane River Model in Idaho: Boundary Conditions and Model Setup and Calibration for 2001 and 2004 Author: Annear, Robert Leslie, Wells, Scott A., Berger, Chris Year: 2005 As a result of a Total Maximum Daily Load (TMDL) study of the Spokane River in Washington, a hydrodynamic and water quality model for the Spokane River was developed by Portland State University (PSU) for the Corps of Engineers and the Washington Department of Ecology from the Washington-Idaho state line to the outlet of Long Lake. An earlier study of the Spokane River was undertaken by Limno-Tech (2001a, 2001b) for the domain shown in Figure 3. Limno-Tech used an earlier version of CE-QUAL-W2, Version 2, for the Reservoir portion of the Spokane River from Post Falls Dam to Coeur d’Alene Lake and a steady-state EPA model, QUAL2E, for the riverine section from Post Falls Dam to the Idaho-Washington State Line. The steady-state QUAL2E model was not adequate to deal with flow and water quality dynamics. Hence, the riverine portion of the model and the reservoir portion were both upgraded to CE-QUAL-W2 Version 3.1. PSU developed the CE-QUAL-W2 model, but did not have adequate data for model calibration. The set-up of this model was described in the following report: * Wells et al. (2003) - Upper Spokane River Model in Idaho: Boundary Conditions and Model Setup for 2001 Because of the necessity of looking at the entire river basin, a model using CE-QUAL-W2 Version 3.1 of the Idaho portion of the Spokane River model was developed to assess water quality management strategies for the Idaho side of the Spokane River. The objective of this study was to use new field data from 2001 and 2004 to improve the model calibration for the Idaho portion of the Spokane River and reevaluate the work done by Wells et al. (2003). Close

• 18. [Image] Summary Review of Available Models for Groundwater Flow and Contaminant Migration

  	Citation × Citation Citation Abstract Copy Title: Summary Review of Available Models for Groundwater Flow and Contaminant Migration Year: 1993 Title: Summary Review of Available Models for Groundwater Flow and Contaminant Migration Year: 1993 Close

• 19. [Article] A macroscale measurement and modeling approach to improve understanding of the hydrology of steep, forested hillslopes

  The dominant controls on flow generation in steep, forested hillslopes are poorly understood. This dissertation examined the dominant flow processes operating at the hillslope scale, using a combined ...

  Citation × Citation Citation Abstract Copy Title: A macroscale measurement and modeling approach to improve understanding of the hydrology of steep, forested hillslopes Author: Graham, Christopher Brian The dominant controls on flow generation in steep, forested hillslopes are poorly understood. This dissertation examined the dominant flow processes operating at the hillslope scale, using a combined macroscale measurement and model development and analysis framework. Irrigation experiments at two steep forested hillslopes were conducted to isolate individual hillslope flow components and reveal the dominant controls on flow routing to the stream. A new perceptual model of flow processes at the hillslope scale was developed from these field experiments that included three key components: 1) A connected preferential flow network located at the soil/bedrock interface controls lateral water and solute transport, 2) The bedrock surface controls the subsurface flow routing, and 3) Bedrock is permeable, and acts as a sink for precipitation at the hillslope scale. These components formed the basis of a new, low dimensional numerical model that was used to represent, quantitatively, qualitative experimental findings. A multiple criteria calibration using hydrometric and tracer experimental data was conducted to evaluate the model and determine parameter identifiability. The model was able to adequately reproduce both hydrometric response to precipitation, and a tracer application breakthrough. The model was then used within a virtual experiment framework to test the dominant controls on the whole storm precipitation / discharge threshold relationship at the catchment scale. The modeling experiments showed that the macroscale precipitation / discharge threshold was controlled by a balance between antecedent evaporation (evaporation rate times antecedent drainage time), and geologic factors (bedrock permeability and subsurface storage volume). Overall, these findings suggest that making measurements at the scale of the processes one wishes to understand, and constructing numerical models based on the dominant processes at the same scale may be a first step towards the development of macroscale laws of hillslope behavior. Title: A macroscale measurement and modeling approach to improve understanding of the hydrology of steep, forested hillslopes Author: Graham, Christopher Brian The dominant controls on flow generation in steep, forested hillslopes are poorly understood. This dissertation examined the dominant flow processes operating at the hillslope scale, using a combined macroscale measurement and model development and analysis framework. Irrigation experiments at two steep forested hillslopes were conducted to isolate individual hillslope flow components and reveal the dominant controls on flow routing to the stream. A new perceptual model of flow processes at the hillslope scale was developed from these field experiments that included three key components: 1) A connected preferential flow network located at the soil/bedrock interface controls lateral water and solute transport, 2) The bedrock surface controls the subsurface flow routing, and 3) Bedrock is permeable, and acts as a sink for precipitation at the hillslope scale. These components formed the basis of a new, low dimensional numerical model that was used to represent, quantitatively, qualitative experimental findings. A multiple criteria calibration using hydrometric and tracer experimental data was conducted to evaluate the model and determine parameter identifiability. The model was able to adequately reproduce both hydrometric response to precipitation, and a tracer application breakthrough. The model was then used within a virtual experiment framework to test the dominant controls on the whole storm precipitation / discharge threshold relationship at the catchment scale. The modeling experiments showed that the macroscale precipitation / discharge threshold was controlled by a balance between antecedent evaporation (evaporation rate times antecedent drainage time), and geologic factors (bedrock permeability and subsurface storage volume). Overall, these findings suggest that making measurements at the scale of the processes one wishes to understand, and constructing numerical models based on the dominant processes at the same scale may be a first step towards the development of macroscale laws of hillslope behavior. Close

• 20. [Image] Stream Flow Gauging

  	Citation × Citation Citation Abstract Copy Title: Stream Flow Gauging Year: 1997 Title: Stream Flow Gauging Year: 1997 Close

• 21. [Image] Unsteady Flow and Fluid Transients

  	Citation × Citation Citation Abstract Copy Title: Unsteady Flow and Fluid Transients Year: 1992 Title: Unsteady Flow and Fluid Transients Year: 1992 Close

• 22. [Article] Funneled flow mechanisms in a sloping layered soil: Laboratory investigation

  This is the publisher’s final pdf. The published article is copyrighted by American Geophysical Union and can be found at: http://sites.agu.org/.

  Citation × Citation Citation Abstract Copy Title: Funneled flow mechanisms in a sloping layered soil: Laboratory investigation Author: Braddock, R. D., Selker, J. S., Steenhuis, T. S., Parlange, J.-Y., Kim, J.-S., Boll, J., Walter, M. T., Heilig, A. This is the publisher’s final pdf. The published article is copyrighted by American Geophysical Union and can be found at: http://sites.agu.org/. Title: Funneled flow mechanisms in a sloping layered soil: Laboratory investigation Author: Braddock, R. D., Selker, J. S., Steenhuis, T. S., Parlange, J.-Y., Kim, J.-S., Boll, J., Walter, M. T., Heilig, A. This is the publisher’s final pdf. The published article is copyrighted by American Geophysical Union and can be found at: http://sites.agu.org/. Close

• 23. [Article] Modeling Density Currents in Circular Clarifiers

  Design of sedimentation tanks for solid-liquid separation is often dependent on assuming ideal flow conditions. But the geometry of the tank and density currents as a result of temperature and suspended ...

  Citation × Citation Citation Abstract Copy Title: Modeling Density Currents in Circular Clarifiers Author: Wells, Scott A., LaLiberte, David M. Year: 1998 Design of sedimentation tanks for solid-liquid separation is often dependent on assuming ideal flow conditions. But the geometry of the tank and density currents as a result of temperature and suspended solids influences the fluid mechanics of the tank and can result in significant deviations from ideal flow. A two-dimensional radial flow model was proposed which incorporated the effect of density currents resulting from temperature and suspended solids differentials within the tank. The numerical model predicted the steady-state, layer-averaged radial flow and layer depth. The model solution and field data showed that the momentum and suspended solids of the inflow caused a density current that moved along the clarifier bottom. In the winter, this density current rose as a result of warm inflow water after the initial momentum had decreased and the suspended solids had settled. Title: Modeling Density Currents in Circular Clarifiers Author: Wells, Scott A., LaLiberte, David M. Year: 1998 Design of sedimentation tanks for solid-liquid separation is often dependent on assuming ideal flow conditions. But the geometry of the tank and density currents as a result of temperature and suspended solids influences the fluid mechanics of the tank and can result in significant deviations from ideal flow. A two-dimensional radial flow model was proposed which incorporated the effect of density currents resulting from temperature and suspended solids differentials within the tank. The numerical model predicted the steady-state, layer-averaged radial flow and layer depth. The model solution and field data showed that the momentum and suspended solids of the inflow caused a density current that moved along the clarifier bottom. In the winter, this density current rose as a result of warm inflow water after the initial momentum had decreased and the suspended solids had settled. Close

• 24. [Article] A Novel Approach to Flow Estimation in Tidal Rivers

  Reliable estimation of river discharge to the ocean from large tidal rivers is vital for water resources management and climate analyses. Due to the difficulties inherent in measuring tidal-river discharge, ...

  Citation × Citation Citation Abstract Copy Title: A Novel Approach to Flow Estimation in Tidal Rivers Author: Moftakhari Rostamkhani, Hamed, Jay, David A, Talke, Stefan A., Kukulka, Tobias, Bromirski, Peter D. Year: 2013 Reliable estimation of river discharge to the ocean from large tidal rivers is vital for water resources management and climate analyses. Due to the difficulties inherent in measuring tidal-river discharge, flow records are often limited in length and/or quality and tidal records often predate discharge records. Tidal theory indicates that tides and river discharge interact through quadratic bed friction, which diminishes and distorts the tidal wave as discharge increases. We use this phenomenon to develop a method of estimating river discharge for time periods with tidal data but no flow record. Employing sequential 32 day harmonic analyses of tidal properties, we calibrate San Francisco (SF), CA tide data to the Sacramento River delta outflow index from 1930 to 1990, and use the resulting relationship to hindcast river flow from 1858 to 1929. The M2 admittance (a ratio of the observed M2 tidal constituent to its astronomical forcing) best reproduces high flows, while low-flow periods are better represented by amplitude ratios based on higher harmonics (e.g.). Results show that the annual inflow to SF Bay is now 30% less than before 1900 and confirm that the flood of January 1862 was the largest since 1858. Title: A Novel Approach to Flow Estimation in Tidal Rivers Author: Moftakhari Rostamkhani, Hamed, Jay, David A, Talke, Stefan A., Kukulka, Tobias, Bromirski, Peter D. Year: 2013 Reliable estimation of river discharge to the ocean from large tidal rivers is vital for water resources management and climate analyses. Due to the difficulties inherent in measuring tidal-river discharge, flow records are often limited in length and/or quality and tidal records often predate discharge records. Tidal theory indicates that tides and river discharge interact through quadratic bed friction, which diminishes and distorts the tidal wave as discharge increases. We use this phenomenon to develop a method of estimating river discharge for time periods with tidal data but no flow record. Employing sequential 32 day harmonic analyses of tidal properties, we calibrate San Francisco (SF), CA tide data to the Sacramento River delta outflow index from 1930 to 1990, and use the resulting relationship to hindcast river flow from 1858 to 1929. The M2 admittance (a ratio of the observed M2 tidal constituent to its astronomical forcing) best reproduces high flows, while low-flow periods are better represented by amplitude ratios based on higher harmonics (e.g.). Results show that the annual inflow to SF Bay is now 30% less than before 1900 and confirm that the flood of January 1862 was the largest since 1858. Close

• 25. [Image] Jordan River Average Flows, 1985 - 1990 (Mcm/yr)

  	Citation × Citation Citation Abstract Copy Title: Jordan River Average Flows, 1985 - 1990 (Mcm/yr) Author: Naff, Thomas Year: 1991 Title: Jordan River Average Flows, 1985 - 1990 (Mcm/yr) Author: Naff, Thomas Year: 1991 Close

• 26. [Article] Subsurface flow of a forested riparian area in the Oregon coast range

  This study was undertaken to gain further understanding of the subsurface hydrology for a stream-adjacent riparian area in Western Oregon's Coast Range. Spatial and temporal fluctuations of the free water surface ...

  Citation × Citation Citation Abstract Copy Title: Subsurface flow of a forested riparian area in the Oregon coast range Author: Reiter, Maryanne This study was undertaken to gain further understanding of the subsurface hydrology for a stream-adjacent riparian area in Western Oregon's Coast Range. Spatial and temporal fluctuations of the free water surface of a toeslope, adjacent riparian area, and stream channel in a forested terrace reach were monitored over a period of one year. A total of 27 piezometers were installed (nine in each of three transects established perpendicular to the stream) in a stream-adjacent terrace and hillslope. These piezometers were monitored from September 26, 1989 to July 25, 1990. Results indicate that the direction of flow within a forested terrace can vary throughout the year. During the drier months of September and October, flow direction was generally towards the stream. However, by November the direction of flow for those areas closest to the stream had begun to change. In some cases the direction of flow changed up to 180° from the September direction. The location of influent/effluent zones along the stream (i.e., zones along the stream where the terrace has a lower or higher hydraulic head than the stream, respectively) also varied throughout the year. During October, 1989 the furthest upvalley stream-adjacent piezometer had hydraulic heads greater than the stream for the entire month, while two other stream adjacent piezometers did not. During normal precipitation in January, 1990 both furthest upvalley and the middle stream-adjacent piezometers had hydraulic heads greater than the stream for the entire month. By July, 1990 only the middle stream-adjacent piezometer had a hydraulic head greater than the stream for the entire month, while the furthest upvalley piezometer had a higher head for 33% of the month and the hydraulic head of furthest downvalley piezometer never exceeded that of the stream. For the Deer Creek study site, subsurface velocities were estimated to be in the range of 10-8 to 10-11 m/s resulting in a 3.8 year minimum travel time for storm water to reach the stream. Thus, soil matrix velocities using the Darcy equation were not sufficient to generate stormflow. However, no overland flow was observed during storm events, indicating that alternative subsurface flow pathways, such as macrochannels, are being utilized. Previous research has suggested that the release of water from terrace storage in small headwater streams is no.t sufficient to maintain baseflow. The results of the Deer Creek study support this conclusion. Furthermore, the results of this study indicate that forested riparian areas are hydrologically complex with respect to both space and time and that oversimplification of these systems may lead to misinterpretation of other processes associated with subsurface water dynamics. Title: Subsurface flow of a forested riparian area in the Oregon coast range Author: Reiter, Maryanne This study was undertaken to gain further understanding of the subsurface hydrology for a stream-adjacent riparian area in Western Oregon's Coast Range. Spatial and temporal fluctuations of the free water surface of a toeslope, adjacent riparian area, and stream channel in a forested terrace reach were monitored over a period of one year. A total of 27 piezometers were installed (nine in each of three transects established perpendicular to the stream) in a stream-adjacent terrace and hillslope. These piezometers were monitored from September 26, 1989 to July 25, 1990. Results indicate that the direction of flow within a forested terrace can vary throughout the year. During the drier months of September and October, flow direction was generally towards the stream. However, by November the direction of flow for those areas closest to the stream had begun to change. In some cases the direction of flow changed up to 180° from the September direction. The location of influent/effluent zones along the stream (i.e., zones along the stream where the terrace has a lower or higher hydraulic head than the stream, respectively) also varied throughout the year. During October, 1989 the furthest upvalley stream-adjacent piezometer had hydraulic heads greater than the stream for the entire month, while two other stream adjacent piezometers did not. During normal precipitation in January, 1990 both furthest upvalley and the middle stream-adjacent piezometers had hydraulic heads greater than the stream for the entire month. By July, 1990 only the middle stream-adjacent piezometer had a hydraulic head greater than the stream for the entire month, while the furthest upvalley piezometer had a higher head for 33% of the month and the hydraulic head of furthest downvalley piezometer never exceeded that of the stream. For the Deer Creek study site, subsurface velocities were estimated to be in the range of 10-8 to 10-11 m/s resulting in a 3.8 year minimum travel time for storm water to reach the stream. Thus, soil matrix velocities using the Darcy equation were not sufficient to generate stormflow. However, no overland flow was observed during storm events, indicating that alternative subsurface flow pathways, such as macrochannels, are being utilized. Previous research has suggested that the release of water from terrace storage in small headwater streams is no.t sufficient to maintain baseflow. The results of the Deer Creek study support this conclusion. Furthermore, the results of this study indicate that forested riparian areas are hydrologically complex with respect to both space and time and that oversimplification of these systems may lead to misinterpretation of other processes associated with subsurface water dynamics. Close

• 27. [Article] Will wetlands restoration plans today still be effective tomorrow? Evaluation of performance of potential wetlands for peak flow reduction in future climate scenarios in the Eagle Creek Watershed, IN

  Global climate change is expected to exaggerate the severity of floods and droughts and increase the frequency of extreme streamflow events in the Midwestern United States. Managing these projected impacts ...

  Citation × Citation Citation Abstract Copy Title: Will wetlands restoration plans today still be effective tomorrow? Evaluation of performance of potential wetlands for peak flow reduction in future climate scenarios in the Eagle Creek Watershed, IN Author: Walters, Kelli M. Global climate change is expected to exaggerate the severity of floods and droughts and increase the frequency of extreme streamflow events in the Midwestern United States. Managing these projected impacts poses a major challenge for water resources, conservation, and land use management. Wetlands have been considered as a conservation strategy and work to increase the capacity of watersheds by storing runoff upstream. The implementation of wetlands, especially in tile-drained agricultural watersheds, can reduce peak flows and help mitigate the anticipated impacts of climate change. The goal of this study was to evaluate the long-term performance of wetlands to reduce peak flows in future climate scenarios in the Eagle Creek Watershed in Indiana, as well as to establish a methodology to incorporate climate change into hydrological models to conduct better long-term land management studies and decisions. The Soil and Water Assessment Tool (SWAT) model was forced with bias corrected climate projections from the North American Regional Climate Change Assessment Program (NARCCAP) to evaluate the impacts of climate change on watershed hydrology and the ability of wetlands to reduce peak flows. Long-term monthly streamflow results predicted a slight increase in streamflow in the winter and a slight decrease in the summer from the past (1971-2000) to future (2041-2070) time periods. About half of the climate realizations produced an increase in the Q05 (5% exceedance flow) value and half a decrease, but all predictions agreed that high flow events will increase in frequency in the winter and decrease in the spring and summer. No-flow events, although found to be over-predicted by the hydrological model, showed an increase from the past to the future for all climate realizations. Results from the wetland analysis showed that if all potential wetlands identified in a previous study are installed in the watershed, maximum peak flow reductions of around 20-50 m³/s for the past and future, as well as decreased frequency of extreme events, can be seen. Wetlands proved to be a robust solution for peak flow reduction, producing consistent reductions across all climate projections for both the past and future time periods. Title: Will wetlands restoration plans today still be effective tomorrow? Evaluation of performance of potential wetlands for peak flow reduction in future climate scenarios in the Eagle Creek Watershed, IN Author: Walters, Kelli M. Global climate change is expected to exaggerate the severity of floods and droughts and increase the frequency of extreme streamflow events in the Midwestern United States. Managing these projected impacts poses a major challenge for water resources, conservation, and land use management. Wetlands have been considered as a conservation strategy and work to increase the capacity of watersheds by storing runoff upstream. The implementation of wetlands, especially in tile-drained agricultural watersheds, can reduce peak flows and help mitigate the anticipated impacts of climate change. The goal of this study was to evaluate the long-term performance of wetlands to reduce peak flows in future climate scenarios in the Eagle Creek Watershed in Indiana, as well as to establish a methodology to incorporate climate change into hydrological models to conduct better long-term land management studies and decisions. The Soil and Water Assessment Tool (SWAT) model was forced with bias corrected climate projections from the North American Regional Climate Change Assessment Program (NARCCAP) to evaluate the impacts of climate change on watershed hydrology and the ability of wetlands to reduce peak flows. Long-term monthly streamflow results predicted a slight increase in streamflow in the winter and a slight decrease in the summer from the past (1971-2000) to future (2041-2070) time periods. About half of the climate realizations produced an increase in the Q05 (5% exceedance flow) value and half a decrease, but all predictions agreed that high flow events will increase in frequency in the winter and decrease in the spring and summer. No-flow events, although found to be over-predicted by the hydrological model, showed an increase from the past to the future for all climate realizations. Results from the wetland analysis showed that if all potential wetlands identified in a previous study are installed in the watershed, maximum peak flow reductions of around 20-50 m³/s for the past and future, as well as decreased frequency of extreme events, can be seen. Wetlands proved to be a robust solution for peak flow reduction, producing consistent reductions across all climate projections for both the past and future time periods. Close

• 28. [Article] Amaila Falls Hydroelectric Project Model Development and Scenarios

  The focus of this present study is to perform the following tasks: * Develop a hydrodynamic and water quality model of the reservoir formed by the Amaila Falls Hydroelectric Project * Develop and run modeling ...

  Citation × Citation Citation Abstract Copy Title: Amaila Falls Hydroelectric Project Model Development and Scenarios Author: Berger, Chris, Wells, Scott A., Wells, Vanessa Year: 2010 The focus of this present study is to perform the following tasks: * Develop a hydrodynamic and water quality model of the reservoir formed by the Amaila Falls Hydroelectric Project * Develop and run modeling scenarios Water quality model simulations of the 23.3 km2 reservoir for Amaila Falls Hydroelectric Project were conducted for low, average, and high flow years. A scenario with no vegetation removed from the reservoir for an average flow was also simulated. Conditions downstream of the reservoir were also modeled using a river model. The model used for the reservoir formed by Amaila Falls Hydroelectric Project is the public domain model, CE-QUAL-W2. Title: Amaila Falls Hydroelectric Project Model Development and Scenarios Author: Berger, Chris, Wells, Scott A., Wells, Vanessa Year: 2010 The focus of this present study is to perform the following tasks: * Develop a hydrodynamic and water quality model of the reservoir formed by the Amaila Falls Hydroelectric Project * Develop and run modeling scenarios Water quality model simulations of the 23.3 km2 reservoir for Amaila Falls Hydroelectric Project were conducted for low, average, and high flow years. A scenario with no vegetation removed from the reservoir for an average flow was also simulated. Conditions downstream of the reservoir were also modeled using a river model. The model used for the reservoir formed by Amaila Falls Hydroelectric Project is the public domain model, CE-QUAL-W2. Close

• 29. [Image] Flows in the Lower Jordan River 1985-1990

  	Citation × Citation Citation Abstract Copy Title: Flows in the Lower Jordan River 1985-1990 Author: Naff, Thomas Year: 2008 Title: Flows in the Lower Jordan River 1985-1990 Author: Naff, Thomas Year: 2008 Close

• 30. [Image] Israeli Withdrawals from Yarmuk River Flows at Lake Tiberias Bank

  	Citation × Citation Citation Abstract Copy Title: Israeli Withdrawals from Yarmuk River Flows at Lake Tiberias Bank Year: 2011 Title: Israeli Withdrawals from Yarmuk River Flows at Lake Tiberias Bank Year: 2011 Close

• 31. [Article] Integrated hydrologic and hydrochemical observations of Hidden Creek Lake jökulhlaups, Kennicott Glacier, Alaska

  Hidden Creek Lake (HCL), an ice-marginal lake impounded by Kennicott Glacier, Wrangell Mountains, Alaska, fills annually to ~20 to 30 x ~10⁶ m³ and then drains subglacially within 2 to 3 days. During the ...

  Citation × Citation Citation Abstract Copy Title: Integrated hydrologic and hydrochemical observations of Hidden Creek Lake jökulhlaups, Kennicott Glacier, Alaska Author: Anderson, Suzanne P., Walder, Joseph S., Anderson, Robert S., Kraal, Erin R., Cunico, Michelle, Fountain, Andrew G., Trabant, Dennis C. Year: 2003 Hidden Creek Lake (HCL), an ice-marginal lake impounded by Kennicott Glacier, Wrangell Mountains, Alaska, fills annually to ~20 to 30 x ~10⁶ m³ and then drains subglacially within 2 to 3 days. During the 1999 and 2000 jökulhlaups, we carried out a series of planned observations around the lake and in the Kennicott River, which drains the glacier. Approximately 20% of the lake volume was contained within a subglacial water ‘‘wedge’’ beneath the ice dam. The entire volume of the lake drains through the wedge; hydraulic head loss through this constriction may be responsible for the fairly symmetrical shape of the HCL outflow hydrographs, deduced from lake level records, basin hypsometry, and collapse of the ice dam. The flood hydrographs in the Kennicott River are similar in shape to the outflow hydrographs, and within error, lake volume matched the river flood volume in both years. Up to 12 x 10⁶ m³ of water was temporarily stored within the glacier during the 2000 jökulhlaup. During the 2000 jökulhlaup the background flow in the Kennicott River shifted to a dilute chemical composition. As the HCL jökulhlaup progressed, Donoho Falls Lake filled with water whose chemistry was closer to that of the background flow in Kennicott River than to HCL water. Comparison of these chemical signals with typical summer variations in Kennicott River chemistry suggests that the jökulhlaup created high subglacial water pressure that impeded normal drainage of solute-rich water from a distributed drainage system into a conduit system at the glacier bed and even caused flow direction locally to reverse. Title: Integrated hydrologic and hydrochemical observations of Hidden Creek Lake jökulhlaups, Kennicott Glacier, Alaska Author: Anderson, Suzanne P., Walder, Joseph S., Anderson, Robert S., Kraal, Erin R., Cunico, Michelle, Fountain, Andrew G., Trabant, Dennis C. Year: 2003 Hidden Creek Lake (HCL), an ice-marginal lake impounded by Kennicott Glacier, Wrangell Mountains, Alaska, fills annually to ~20 to 30 x ~10⁶ m³ and then drains subglacially within 2 to 3 days. During the 1999 and 2000 jökulhlaups, we carried out a series of planned observations around the lake and in the Kennicott River, which drains the glacier. Approximately 20% of the lake volume was contained within a subglacial water ‘‘wedge’’ beneath the ice dam. The entire volume of the lake drains through the wedge; hydraulic head loss through this constriction may be responsible for the fairly symmetrical shape of the HCL outflow hydrographs, deduced from lake level records, basin hypsometry, and collapse of the ice dam. The flood hydrographs in the Kennicott River are similar in shape to the outflow hydrographs, and within error, lake volume matched the river flood volume in both years. Up to 12 x 10⁶ m³ of water was temporarily stored within the glacier during the 2000 jökulhlaup. During the 2000 jökulhlaup the background flow in the Kennicott River shifted to a dilute chemical composition. As the HCL jökulhlaup progressed, Donoho Falls Lake filled with water whose chemistry was closer to that of the background flow in Kennicott River than to HCL water. Comparison of these chemical signals with typical summer variations in Kennicott River chemistry suggests that the jökulhlaup created high subglacial water pressure that impeded normal drainage of solute-rich water from a distributed drainage system into a conduit system at the glacier bed and even caused flow direction locally to reverse. Close

• 32. [Article] Validation of the CE-QUAL-W2 Version 3 River Basin Hydrodynamic and Water Quality Model

  CE-QUAL-W2 Version 3, a 2-D (longitudinal-vertical) hydrodynamic and water quality model for river basins combining both river and stratified river-estuary and lakereservoir flow, is a development product ...

  Citation × Citation Citation Abstract Copy Title: Validation of the CE-QUAL-W2 Version 3 River Basin Hydrodynamic and Water Quality Model Author: Wells, Scott A. Year: 2002 CE-QUAL-W2 Version 3, a 2-D (longitudinal-vertical) hydrodynamic and water quality model for river basins combining both river and stratified river-estuary and lakereservoir flow, is a development product of the Waterways Experiment Station in Vicksburg, MS, USA. With the development and release of any revised or reformulated model codes, significant model validation is required. This includes comparison of model results to simple analytical solutions for hydrodynamics and water quality transport, as well as comparison to laboratory and field data. In this paper, the model is compared to numerous analytical solutions for mass transport (1-D advective mass transport) and hydrodynamics (impulsive wind stress on water surface, seiching). Suggestions are presented for proper validation protocols for hydrodynamic and water quality models. Title: Validation of the CE-QUAL-W2 Version 3 River Basin Hydrodynamic and Water Quality Model Author: Wells, Scott A. Year: 2002 CE-QUAL-W2 Version 3, a 2-D (longitudinal-vertical) hydrodynamic and water quality model for river basins combining both river and stratified river-estuary and lakereservoir flow, is a development product of the Waterways Experiment Station in Vicksburg, MS, USA. With the development and release of any revised or reformulated model codes, significant model validation is required. This includes comparison of model results to simple analytical solutions for hydrodynamics and water quality transport, as well as comparison to laboratory and field data. In this paper, the model is compared to numerous analytical solutions for mass transport (1-D advective mass transport) and hydrodynamics (impulsive wind stress on water surface, seiching). Suggestions are presented for proper validation protocols for hydrodynamic and water quality models. Close

• 33. [Article] Basis of the CE-QUAL-W2 Version 3 River Basin Hydrodynamic and Water Quality Model

  CE-QUAL-W2 Version 3, a 2-D (longitudinal-vertical) hydrodynamic and water quality model for river basins combining both river and stratified river-estuary and lake-reservoir flow, is a development product ...

  Citation × Citation Citation Abstract Copy Title: Basis of the CE-QUAL-W2 Version 3 River Basin Hydrodynamic and Water Quality Model Author: Wells, Scott A. Year: 2002 CE-QUAL-W2 Version 3, a 2-D (longitudinal-vertical) hydrodynamic and water quality model for river basins combining both river and stratified river-estuary and lake-reservoir flow, is a development product of the Waterways Experiment Station in Vicksburg, MS, USA. With the development and release of any revised or reformulated model codes, significant model validation is required. This includes comparison of model results to simple analytical solutions for hydrodynamics and water quality transport, as well as comparison to laboratory and field data. In this paper, the model is compared to numerous analytical solutions for mass transport (1- D advective mass transport) and hydrodynamics (impulsive wind stress on water surface, seiching). Suggestions are presented for proper validation protocols for hydrodynamic and water quality models. Title: Basis of the CE-QUAL-W2 Version 3 River Basin Hydrodynamic and Water Quality Model Author: Wells, Scott A. Year: 2002 CE-QUAL-W2 Version 3, a 2-D (longitudinal-vertical) hydrodynamic and water quality model for river basins combining both river and stratified river-estuary and lake-reservoir flow, is a development product of the Waterways Experiment Station in Vicksburg, MS, USA. With the development and release of any revised or reformulated model codes, significant model validation is required. This includes comparison of model results to simple analytical solutions for hydrodynamics and water quality transport, as well as comparison to laboratory and field data. In this paper, the model is compared to numerous analytical solutions for mass transport (1- D advective mass transport) and hydrodynamics (impulsive wind stress on water surface, seiching). Suggestions are presented for proper validation protocols for hydrodynamic and water quality models. Close

• 34. [Article] TMDLS: Statistical Correlations or Mechanistic Modeling?

  Western Idaho and Eastern Oregon, determinations of the assimilative capacity of the system and the impact of pollutant reduction strategies has been performed using both a statistical-correlation approach ...

  Citation × Citation Citation Abstract Copy Title: TMDLS: Statistical Correlations or Mechanistic Modeling? Author: Wells, Scott A., Cole, Thomas M. Year: 2002 Western Idaho and Eastern Oregon, determinations of the assimilative capacity of the system and the impact of pollutant reduction strategies has been performed using both a statistical-correlation approach and a mechanistic modeling approach. The system included the Lower Snake River, Brownlee Reservoir, Oxbow Reservoir, and Hells Canyon Reservoir with the focus was on Brownlee Reservoir. The statistical approach used on Brownlee Reservoir divided the system into riverine and lacustrine zones. Field data were then averaged over season and location to provide statistical correlations, such as between total phosphorus (TP) and chlorophyll a (chl a), between an anoxic factor (AF) and TP, and between a hypoxic factor (HP) and TP. The anoxic factor is defined as the number of days when dissolved oxygen was less than 2 mg/l and the hypoxic factor was defined as the number of days when dissolved oxygen was less than 6.5 mg/l. The mechanistic approach used a two-dimensional, unsteady, hydrodynamic and water quality model called CE-QUAL-W2. The model was calibrated to field data over a three year period for 1992 (a low flow year), 1995 (an average flow year), and 1997 (a high flow year). Some of the important questions that the TMDL process was to answer included the following. What level of TP is necessary in the river coming into Brownlee Reservoir to reduce the number of days of hypoxia in the reservoir? What are the causes of low2 dissolved oxygen in Brownlee Reservoir and what management strategies can be implemented to improve water quality? This paper examines the strengths and weaknesses of answering management questions using these two approaches. Recommendations are suggested for answering assimilative capacity questions that arise in TMDL studies. Title: TMDLS: Statistical Correlations or Mechanistic Modeling? Author: Wells, Scott A., Cole, Thomas M. Year: 2002 Western Idaho and Eastern Oregon, determinations of the assimilative capacity of the system and the impact of pollutant reduction strategies has been performed using both a statistical-correlation approach and a mechanistic modeling approach. The system included the Lower Snake River, Brownlee Reservoir, Oxbow Reservoir, and Hells Canyon Reservoir with the focus was on Brownlee Reservoir. The statistical approach used on Brownlee Reservoir divided the system into riverine and lacustrine zones. Field data were then averaged over season and location to provide statistical correlations, such as between total phosphorus (TP) and chlorophyll a (chl a), between an anoxic factor (AF) and TP, and between a hypoxic factor (HP) and TP. The anoxic factor is defined as the number of days when dissolved oxygen was less than 2 mg/l and the hypoxic factor was defined as the number of days when dissolved oxygen was less than 6.5 mg/l. The mechanistic approach used a two-dimensional, unsteady, hydrodynamic and water quality model called CE-QUAL-W2. The model was calibrated to field data over a three year period for 1992 (a low flow year), 1995 (an average flow year), and 1997 (a high flow year). Some of the important questions that the TMDL process was to answer included the following. What level of TP is necessary in the river coming into Brownlee Reservoir to reduce the number of days of hypoxia in the reservoir? What are the causes of low2 dissolved oxygen in Brownlee Reservoir and what management strategies can be implemented to improve water quality? This paper examines the strengths and weaknesses of answering management questions using these two approaches. Recommendations are suggested for answering assimilative capacity questions that arise in TMDL studies. Close

• 35. [Article] Green River CE-QUAL-W2 Project: A Hydrodynamic and Water Quality Study of the Green River King County, Washington

  This report describes the data processing and model calibration performed for a hydrodynamic and water quality model of the Green River, located in King County, Washington. Figure 1 shows the location ...

  Citation × Citation Citation Abstract Copy Title: Green River CE-QUAL-W2 Project: A Hydrodynamic and Water Quality Study of the Green River King County, Washington Author: Kraft, Tim, Annear, Robert Leslie, Berger, Chris, Wells, Scott A. Year: 2004 This report describes the data processing and model calibration performed for a hydrodynamic and water quality model of the Green River, located in King County, Washington. Figure 1 shows the location of the river, and the limits of the section of river that was modeled. The Green River flows from its headwaters in the Cascade Mountain foothills through the King County, Washington communities of Auburn, Kent, and Tukwila before discharging into the Duwamish River. Two sections of the river were modeled in this project. The Middle Green River begins in the Cascade Mountain foothills east of Tacoma, and continues downstream to the city of Auburn, WA. The Lower Green River continues from Auburn to the confluence with the Duwamish River, in the town of Tukwila. The Green/Duwamish River system is unique in that it flows through a heavily urbanized and industrialized environment yet supports a large salmon population (Green/Duwamish Ecosystem Restoration Study, 2003). To protect the river and its prime salmon habitat, King County and the US Army Corps of Engineers have joined together on a study to identify and implement strategies for restoring and protecting the Green/Duwamish River System and its tributaries (Green/Duwamish Ecosystem Restoration Study, 2003). As part of the Green-Duwamish Watershed Water Quality Assessment Program, King County contracted with Portland State University to develop a hydrodynamic and water quality model for the Lower and Middle Green River. This model will be used in Total Maximum Daily Load (TMDL) development, in assessing current water quality conditions in the river, and as a planning tool for evaluating the impacts of future development in the basin. Title: Green River CE-QUAL-W2 Project: A Hydrodynamic and Water Quality Study of the Green River King County, Washington Author: Kraft, Tim, Annear, Robert Leslie, Berger, Chris, Wells, Scott A. Year: 2004 This report describes the data processing and model calibration performed for a hydrodynamic and water quality model of the Green River, located in King County, Washington. Figure 1 shows the location of the river, and the limits of the section of river that was modeled. The Green River flows from its headwaters in the Cascade Mountain foothills through the King County, Washington communities of Auburn, Kent, and Tukwila before discharging into the Duwamish River. Two sections of the river were modeled in this project. The Middle Green River begins in the Cascade Mountain foothills east of Tacoma, and continues downstream to the city of Auburn, WA. The Lower Green River continues from Auburn to the confluence with the Duwamish River, in the town of Tukwila. The Green/Duwamish River system is unique in that it flows through a heavily urbanized and industrialized environment yet supports a large salmon population (Green/Duwamish Ecosystem Restoration Study, 2003). To protect the river and its prime salmon habitat, King County and the US Army Corps of Engineers have joined together on a study to identify and implement strategies for restoring and protecting the Green/Duwamish River System and its tributaries (Green/Duwamish Ecosystem Restoration Study, 2003). As part of the Green-Duwamish Watershed Water Quality Assessment Program, King County contracted with Portland State University to develop a hydrodynamic and water quality model for the Lower and Middle Green River. This model will be used in Total Maximum Daily Load (TMDL) development, in assessing current water quality conditions in the river, and as a planning tool for evaluating the impacts of future development in the basin. Close

• 36. [Article] Tidal-Fluvial and Estuarine Processes in the Lower Columbia River: II. Water Level Models, Floodplain Wetland Inundation, and System Zones

  Spatially varying water-level regimes are a factor controlling estuarine and tidal-fluvial wetland vegetation patterns. As described in Part I, water levels in the Lower Columbia River and estuary (LCRE) ...

  Citation × Citation Citation Abstract Copy Title: Tidal-Fluvial and Estuarine Processes in the Lower Columbia River: II. Water Level Models, Floodplain Wetland Inundation, and System Zones Author: Jay, David A, Borde, Amy B., Diefenderfer, Heida Year: 2016 Spatially varying water-level regimes are a factor controlling estuarine and tidal-fluvial wetland vegetation patterns. As described in Part I, water levels in the Lower Columbia River and estuary (LCRE) are influenced by tides, river flow, hydropower operations, and coastal processes. In Part II, regression models based on tidal theory are used to quantify the role of these processes in determining water levels in the mainstem river and floodplain wetlands, and to provide 21-year inundation hindcasts. Analyses are conducted at 19 LCRE mainstem channel stations and 23 tidally exposed floodplain wetland stations. Sum exceedance values (SEVs) are used to compare wetland hydrologic regimes at different locations on the river floodplain. A new predictive tool is introduced and validated, the potential SEV (pSEV), which can reduce the need for extensive new data collection in wetland restoration planning. Models of water levels and inundation frequency distinguish four zones encompassing eight reaches. The system zones are the wave- and current-dominated Entrance to river kilometer (rkm) 5; the Estuary (rkm-5 to 87), comprised of a lower reach with salinity, the energy minimum (where the turbidity maximum normally occurs), and an upper estuary reach without salinity; the Tidal River (rkm-87 to 229), with lower, middle, and upper reaches in which river flow becomes increasingly dominant over tides in determining water levels; and the steep and weakly tidal Cascade (rkm-229 to 234) immediately downstream from Bonneville Dam. The same zonation is seen in the water levels of floodplain stations, with considerable modification of tidal properties. The system zones and reaches defined here reflect geological features and their boundaries are congruent with five wetland vegetation zones. Title: Tidal-Fluvial and Estuarine Processes in the Lower Columbia River: II. Water Level Models, Floodplain Wetland Inundation, and System Zones Author: Jay, David A, Borde, Amy B., Diefenderfer, Heida Year: 2016 Spatially varying water-level regimes are a factor controlling estuarine and tidal-fluvial wetland vegetation patterns. As described in Part I, water levels in the Lower Columbia River and estuary (LCRE) are influenced by tides, river flow, hydropower operations, and coastal processes. In Part II, regression models based on tidal theory are used to quantify the role of these processes in determining water levels in the mainstem river and floodplain wetlands, and to provide 21-year inundation hindcasts. Analyses are conducted at 19 LCRE mainstem channel stations and 23 tidally exposed floodplain wetland stations. Sum exceedance values (SEVs) are used to compare wetland hydrologic regimes at different locations on the river floodplain. A new predictive tool is introduced and validated, the potential SEV (pSEV), which can reduce the need for extensive new data collection in wetland restoration planning. Models of water levels and inundation frequency distinguish four zones encompassing eight reaches. The system zones are the wave- and current-dominated Entrance to river kilometer (rkm) 5; the Estuary (rkm-5 to 87), comprised of a lower reach with salinity, the energy minimum (where the turbidity maximum normally occurs), and an upper estuary reach without salinity; the Tidal River (rkm-87 to 229), with lower, middle, and upper reaches in which river flow becomes increasingly dominant over tides in determining water levels; and the steep and weakly tidal Cascade (rkm-229 to 234) immediately downstream from Bonneville Dam. The same zonation is seen in the water levels of floodplain stations, with considerable modification of tidal properties. The system zones and reaches defined here reflect geological features and their boundaries are congruent with five wetland vegetation zones. Close

• 37. [Article] Spatial identification and optimization of upland wetlands in agricultural watersheds

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier ...

  Citation × Citation Citation Abstract Copy Title: Spatial identification and optimization of upland wetlands in agricultural watersheds Author: Barr, Robert C., Babbar-Sebens, Meghna, Anderson, Milo, Tedesco, Lenore P. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.elsevier.com/. Title: Spatial identification and optimization of upland wetlands in agricultural watersheds Author: Barr, Robert C., Babbar-Sebens, Meghna, Anderson, Milo, Tedesco, Lenore P. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.elsevier.com/. Close

• 38. [Image] Flow and Exploration of Yarmouk in Summer Months (May 15 to Oct. 15) and in winter months (Oct. 15 to May 15)

  	Citation × Citation Citation Abstract Copy Title: Flow and Exploration of Yarmouk in Summer Months (May 15 to Oct. 15) and in winter months (Oct. 15 to May 15) Year: 1992 Title: Flow and Exploration of Yarmouk in Summer Months (May 15 to Oct. 15) and in winter months (Oct. 15 to May 15) Year: 1992 Close

• 39. [Image] Hydro-geological Data on Yarmouk River (Jordan), Including Wells, Chemical Analyses, Maps, Flows, Etc. Data collected by AMER Statt, 1985-1990.

  	Citation × Citation Citation Abstract Copy Title: Hydro-geological Data on Yarmouk River (Jordan), Including Wells, Chemical Analyses, Maps, Flows, Etc. Data collected by AMER Statt, 1985-1990. Author: Associates for Middle East Research Year: 1990 Title: Hydro-geological Data on Yarmouk River (Jordan), Including Wells, Chemical Analyses, Maps, Flows, Etc. Data collected by AMER Statt, 1985-1990. Author: Associates for Middle East Research Year: 1990 Close

• 40. [Article] Rainfall-Runoff Prediction and the Effects of Logging : The Oregon Coast Range

  Streamflow response to rainfall is controlled by the net water budget and the routing of rainfall to stream channels. In rain-dominated forested regions, including the Oregon Coast Range, water budget ...

  Citation × Citation Citation Abstract Copy Title: Rainfall-Runoff Prediction and the Effects of Logging : The Oregon Coast Range Author: Van Haveren, Bruce P., Jackson, William L. (William Longstreth) Streamflow response to rainfall is controlled by the net water budget and the routing of rainfall to stream channels. In rain-dominated forested regions, including the Oregon Coast Range, water budget aspects of forest hydrology are better quantified than water routing. As a result, most of the commonly used forest hydrology models have been designed to assist in the analysis of seasonal or annual runoff volumes (Goldstein, et al. 1974; Troendle and Leaf, 1980; Silvey and Rosgen, 1981). The effects of timber harvesting on runoff volumes are reflected primarily through reductions in evapotranspirational demand and the corresponding increases in soil water content. The purposes of the report are to: (1) Describe the rainfall-runoff processes in the Oregon Coast Range, and review the results of studies in Western Oregon on the effects of timber harvesting on runoff. (2) Review and analyze available techniques for predicting the hydrologic effects of timber harvesting in rainfall-dominated regions. (3) Provide a review of the issue of sediment routing, channel stability, and the relationship between hydrology and channel morphology. (4) Provide additional analysis of the Alsea Watershed Study data (Harris, 1977) to better describe the effects of timber harvesting on high-flow durations and assess the potential for developing and validating simple storm-period rainfall-runoff prediction procedures. Title: Rainfall-Runoff Prediction and the Effects of Logging : The Oregon Coast Range Author: Van Haveren, Bruce P., Jackson, William L. (William Longstreth) Streamflow response to rainfall is controlled by the net water budget and the routing of rainfall to stream channels. In rain-dominated forested regions, including the Oregon Coast Range, water budget aspects of forest hydrology are better quantified than water routing. As a result, most of the commonly used forest hydrology models have been designed to assist in the analysis of seasonal or annual runoff volumes (Goldstein, et al. 1974; Troendle and Leaf, 1980; Silvey and Rosgen, 1981). The effects of timber harvesting on runoff volumes are reflected primarily through reductions in evapotranspirational demand and the corresponding increases in soil water content. The purposes of the report are to: (1) Describe the rainfall-runoff processes in the Oregon Coast Range, and review the results of studies in Western Oregon on the effects of timber harvesting on runoff. (2) Review and analyze available techniques for predicting the hydrologic effects of timber harvesting in rainfall-dominated regions. (3) Provide a review of the issue of sediment routing, channel stability, and the relationship between hydrology and channel morphology. (4) Provide additional analysis of the Alsea Watershed Study data (Harris, 1977) to better describe the effects of timber harvesting on high-flow durations and assess the potential for developing and validating simple storm-period rainfall-runoff prediction procedures. Close

• 41. [Article] TMDLS: Statistical Correlations or Mechanistic Modeling?

  In developing TMDL waste-load allocations for the Snake River-Reservoir system in Western Idaho and Eastern Oregon, determinations of the assimilative capacity of the system and the impact of pollutant ...

  Citation × Citation Citation Abstract Copy Title: TMDLS: Statistical Correlations or Mechanistic Modeling? Author: Wells, Scott A., Cole, Thomas M. Year: 2002 In developing TMDL waste-load allocations for the Snake River-Reservoir system in Western Idaho and Eastern Oregon, determinations of the assimilative capacity of the system and the impact of pollutant reduction strategies has been performed using both a statistical-correlation approach and a mechanistic modeling approach. The system included the Lower Snake River, Brownlee Reservoir, Oxbow Reservoir, and Hells Canyon Reservoir with the focus was on Brownlee Reservoir. The statistical approach used on Brownlee Reservoir divided the system into riverine and lacustrine zones. Field data were then averaged over season and location to provide statistical correlations, such as between total phosphorus (TP) and chlorophyll a (chl a), between an anoxic factor (AF) and TP, and between a hypoxic factor (HP) and TP. The anoxic factor is defined as the number of days when dissolved oxygen was less than 2 mg/l and the hypoxic factor was defined as the number of days when dissolved oxygen was less than 6.5 mg/l. The mechanistic approach used a two-dimensional, unsteady, hydrodynamic and water quality model called CE-QUAL-W2. The model was calibrated to field data over a three year period for 1992 (a low flow year), 1995 (an average flow year), and 1997 (a high flow year). Some of the important questions that the TMDL process was to answer included the following. What level of TP is necessary in the river coming into Brownlee Reservoir to reduce the number of days of hypoxia in the reservoir? What are the causes of low-dissolved oxygen in Brownlee Reservoir and what management strategies can be implemented to improve water quality? This paper examines the strengths and weaknesses of answering management questions using these two approaches. Recommendations are suggested for answering assimilative capacity questions that arise in TMDL studies. Title: TMDLS: Statistical Correlations or Mechanistic Modeling? Author: Wells, Scott A., Cole, Thomas M. Year: 2002 In developing TMDL waste-load allocations for the Snake River-Reservoir system in Western Idaho and Eastern Oregon, determinations of the assimilative capacity of the system and the impact of pollutant reduction strategies has been performed using both a statistical-correlation approach and a mechanistic modeling approach. The system included the Lower Snake River, Brownlee Reservoir, Oxbow Reservoir, and Hells Canyon Reservoir with the focus was on Brownlee Reservoir. The statistical approach used on Brownlee Reservoir divided the system into riverine and lacustrine zones. Field data were then averaged over season and location to provide statistical correlations, such as between total phosphorus (TP) and chlorophyll a (chl a), between an anoxic factor (AF) and TP, and between a hypoxic factor (HP) and TP. The anoxic factor is defined as the number of days when dissolved oxygen was less than 2 mg/l and the hypoxic factor was defined as the number of days when dissolved oxygen was less than 6.5 mg/l. The mechanistic approach used a two-dimensional, unsteady, hydrodynamic and water quality model called CE-QUAL-W2. The model was calibrated to field data over a three year period for 1992 (a low flow year), 1995 (an average flow year), and 1997 (a high flow year). Some of the important questions that the TMDL process was to answer included the following. What level of TP is necessary in the river coming into Brownlee Reservoir to reduce the number of days of hypoxia in the reservoir? What are the causes of low-dissolved oxygen in Brownlee Reservoir and what management strategies can be implemented to improve water quality? This paper examines the strengths and weaknesses of answering management questions using these two approaches. Recommendations are suggested for answering assimilative capacity questions that arise in TMDL studies. Close

• 42. [Article] Modeling Effects of Channel Complexity and Hyporheic Flow on Stream Temperatures

  Stream temperatures are affected by multiple forcing functions, including surface heat exchange (including solar radiation, evaporation, conduction, and net long wave radiation) and hyporheic flows. Each ...

  Citation × Citation Citation Abstract Copy Title: Modeling Effects of Channel Complexity and Hyporheic Flow on Stream Temperatures Author: Berger, Chris, Wells, Scott A. Year: 2007 Stream temperatures are affected by multiple forcing functions, including surface heat exchange (including solar radiation, evaporation, conduction, and net long wave radiation) and hyporheic flows. Each of these forcing functions is directly influenced by the level of channel complexity in the stream channel and riparian shading. The interrelationship between channel complexity, hyporheic flow and stream temperature is highly complex, and efforts to manage for habitat diversity by managing channel complexity could result in unintended consequences on stream temperature. When planning modifications to stream channel complexity, consideration should be given to the effects such moderations could have on stream temperatures. Urbanization has impacted many steams due to the construction of bank protections, levees, vegetation removal, etc. Such activities have eliminated side channels and reduced stream braiding, thereby reducing the overall channel complexity. Hulse et al. (2002) developed maps showing the channel configurations of the Willamette River in Oregon, USA in the years 1850 and 1995. These maps show a significant reduction in channel complexity in the intervening years. More complex stream channels provide greater habitat diversity and thus, are generally more desirable from a wildlife management perspective. Therefore, management of streams for increased channel complexity is gaining in popularity. Knowing that stream channel complexity has diminished over time, an important question to consider is ‘what were stream temperatures before we altered the natural channels?’ This is an important issue in determining what natural conditions were and how we have strayed from these so-called ‘natural’ conditions as a result of channelization, dam building, and changes to the riparian vegetation and deforestation. Current Total Maximum Daily Load’s (TMDL) rely on determining a ‘natural’ condition. In order to develop an understanding of what that is, a hydrodynamic and water quality computer simulation model has been applied to Oregon’s Willamette River with several levels of channel complexity and varying rates of hyporheic flows. Adapting the model used to develop TMDL’s for temperature in the Willamette River, the effects of present and past channel complexity on water temperatures was determined. The model used to develop the TMDL was the U. S. Army Corps of Engineers dynamic 2-D model CE-QUAL-W2, which consists of directly coupled hydrodynamic and water quality transport models and simulates parameters such as temperature, algae concentration, dissolved oxygen concentration, pH, nutrient concentrations and residence time. The model also incorporates a dynamic shading algorithm for both vegetative and topographic shading on water bodies. Title: Modeling Effects of Channel Complexity and Hyporheic Flow on Stream Temperatures Author: Berger, Chris, Wells, Scott A. Year: 2007 Stream temperatures are affected by multiple forcing functions, including surface heat exchange (including solar radiation, evaporation, conduction, and net long wave radiation) and hyporheic flows. Each of these forcing functions is directly influenced by the level of channel complexity in the stream channel and riparian shading. The interrelationship between channel complexity, hyporheic flow and stream temperature is highly complex, and efforts to manage for habitat diversity by managing channel complexity could result in unintended consequences on stream temperature. When planning modifications to stream channel complexity, consideration should be given to the effects such moderations could have on stream temperatures. Urbanization has impacted many steams due to the construction of bank protections, levees, vegetation removal, etc. Such activities have eliminated side channels and reduced stream braiding, thereby reducing the overall channel complexity. Hulse et al. (2002) developed maps showing the channel configurations of the Willamette River in Oregon, USA in the years 1850 and 1995. These maps show a significant reduction in channel complexity in the intervening years. More complex stream channels provide greater habitat diversity and thus, are generally more desirable from a wildlife management perspective. Therefore, management of streams for increased channel complexity is gaining in popularity. Knowing that stream channel complexity has diminished over time, an important question to consider is ‘what were stream temperatures before we altered the natural channels?’ This is an important issue in determining what natural conditions were and how we have strayed from these so-called ‘natural’ conditions as a result of channelization, dam building, and changes to the riparian vegetation and deforestation. Current Total Maximum Daily Load’s (TMDL) rely on determining a ‘natural’ condition. In order to develop an understanding of what that is, a hydrodynamic and water quality computer simulation model has been applied to Oregon’s Willamette River with several levels of channel complexity and varying rates of hyporheic flows. Adapting the model used to develop TMDL’s for temperature in the Willamette River, the effects of present and past channel complexity on water temperatures was determined. The model used to develop the TMDL was the U. S. Army Corps of Engineers dynamic 2-D model CE-QUAL-W2, which consists of directly coupled hydrodynamic and water quality transport models and simulates parameters such as temperature, algae concentration, dissolved oxygen concentration, pH, nutrient concentrations and residence time. The model also incorporates a dynamic shading algorithm for both vegetative and topographic shading on water bodies. Close

• 43. [Article] A Stable Isotopic Investigation of a Polar Desert Hydrologic System, McMurdo Dry Valleys, Antarctica

  The hydrologic system of the coastal McMurdo Dry Valleys, Antarctica, is defined by snow accumulation, glacier melt, stream flow, and retention in closed-basin, ice-covered lakes. During the austral summers ...

  Citation × Citation Citation Abstract Copy Title: A Stable Isotopic Investigation of a Polar Desert Hydrologic System, McMurdo Dry Valleys, Antarctica Author: Gooseff, Michael N., Lyons, W. Berry, McKnight, Diane M., Vaughn, Bruce H., Fountain, Andrew G., Dowling, Carolyn Year: 2006 The hydrologic system of the coastal McMurdo Dry Valleys, Antarctica, is defined by snow accumulation, glacier melt, stream flow, and retention in closed-basin, ice-covered lakes. During the austral summers from 1993-1996 and 1999-2000 to 2002-2003, fresh snow, snow pits, glacier ice, stream water, and lake waters were sampled for the stable isotopes deuterium (D) and 18O in order to resolve sources of meltwater and the interactions among the various hydrologic reservoirs in the dry valleys. This data set provides a survey of the distribution of natural water isotope abundances within the well-defined dry valley hydrologic system in Taylor Valley, which extends 20 km inland from McMurdo Sound. The three major Taylor Valley lakes are not connected to one another hydrologically, and their levels are maintained by glacial meltwater inflow and perennial ice-cover sublimation. At the valley scale, glacial ice, snow, stream, and lake waters become more depleted in delta D with increasing distance from McMurdo Sound (further inland). Snow pack in glacial accumulation zones is heterogeneous, likely a result of varying storm sources (continental versus coastal), and, in general, snow pits, fresh snow samples, and glacier ice are more depleted than stream waters. Within the lake basins, glacial ice source waters are depleted by as much as 111ppm delta D and 20 ppm delta 18O compared to lake waters. These results demonstrate the importance of in-stream fractionation at the valley scale. In-stream fractionation occurs through direct evaporation from the channel and hyporheic exchange with isotopically enriched waters in the near-stream subsurface during transport from the glacial source to lake. Furthermore, the results show that lake waters directly reflect their glacial ice sources, despite fractionation during stream transport. Inter-annual comparisons of lake profiles suggest that lake waters are directly influenced by the isotopic composition and amount of stream flow during a season. Title: A Stable Isotopic Investigation of a Polar Desert Hydrologic System, McMurdo Dry Valleys, Antarctica Author: Gooseff, Michael N., Lyons, W. Berry, McKnight, Diane M., Vaughn, Bruce H., Fountain, Andrew G., Dowling, Carolyn Year: 2006 The hydrologic system of the coastal McMurdo Dry Valleys, Antarctica, is defined by snow accumulation, glacier melt, stream flow, and retention in closed-basin, ice-covered lakes. During the austral summers from 1993-1996 and 1999-2000 to 2002-2003, fresh snow, snow pits, glacier ice, stream water, and lake waters were sampled for the stable isotopes deuterium (D) and 18O in order to resolve sources of meltwater and the interactions among the various hydrologic reservoirs in the dry valleys. This data set provides a survey of the distribution of natural water isotope abundances within the well-defined dry valley hydrologic system in Taylor Valley, which extends 20 km inland from McMurdo Sound. The three major Taylor Valley lakes are not connected to one another hydrologically, and their levels are maintained by glacial meltwater inflow and perennial ice-cover sublimation. At the valley scale, glacial ice, snow, stream, and lake waters become more depleted in delta D with increasing distance from McMurdo Sound (further inland). Snow pack in glacial accumulation zones is heterogeneous, likely a result of varying storm sources (continental versus coastal), and, in general, snow pits, fresh snow samples, and glacier ice are more depleted than stream waters. Within the lake basins, glacial ice source waters are depleted by as much as 111ppm delta D and 20 ppm delta 18O compared to lake waters. These results demonstrate the importance of in-stream fractionation at the valley scale. In-stream fractionation occurs through direct evaporation from the channel and hyporheic exchange with isotopically enriched waters in the near-stream subsurface during transport from the glacial source to lake. Furthermore, the results show that lake waters directly reflect their glacial ice sources, despite fractionation during stream transport. Inter-annual comparisons of lake profiles suggest that lake waters are directly influenced by the isotopic composition and amount of stream flow during a season. Close

• 44. [Article] Convergent Surface Water Distributions in U.S. Cities

  Earth's surface is rapidly urbanizing, resulting in dramatic changes in the abundance, distribution and character of surface water features in urban landscapes. However,the scope and consequences of surface ...

  Citation × Citation Citation Abstract Copy Title: Convergent Surface Water Distributions in U.S. Cities Author: Steele, Meredith K., Heffernan, James B., Bettez, Neil D., Cavender-Bares, Jeannine, Groffman, Peter M., Grove, J. Morgan, Hall, Sharon J., Hobbie, Sarah E., Larson, Kelli L., Morse, Jennifer L., Neill, Christopher, Nelson, Kristen C., O'Neil-Dunne, Jarlath, Ogden, Laura A., Pataki, Diane E., Polsky, Colin, Chowdhury, Rinku Roy Year: 2014 Earth's surface is rapidly urbanizing, resulting in dramatic changes in the abundance, distribution and character of surface water features in urban landscapes. However,the scope and consequences of surface water redistribution at broad spatialscales are not well understood. We hypothesized that urbanization would lead to convergent surface water abundance and distribution: in other words, cities will gain or lose water such that they become more similar to each other than are their surrounding natural landscapes. Using a database of more than 1 million water bodies and 1 million km of streams, we compared the surface water of 100 US cities with their surrounding undeveloped land. We evaluated differences in areal ( A) and numeric densities ( N) of water bodies (lakes, wetlands, and so on), the morphological characteristics of water bodies (size), and the density ( D) of surface flow channels (that is, streams and rivers). The variance of urban A, N, and D across the 100 MSAs decreased, by 89, 25, and 71%, respectively, compared to undeveloped land. These data show that many cities are surface water poor relative to undeveloped land; however, in drier landscapesurbanization increases the occurrence of surface water. This convergence pattern strengthened with development intensity, such that high intensityurban development had an areal water body density 98% less than undeveloped lands. Urbanization appears to drive the convergence of hydrological features across the US, such that surface water distributions of cities are more similar to each other than to their surrounding landscapes. Title: Convergent Surface Water Distributions in U.S. Cities Author: Steele, Meredith K., Heffernan, James B., Bettez, Neil D., Cavender-Bares, Jeannine, Groffman, Peter M., Grove, J. Morgan, Hall, Sharon J., Hobbie, Sarah E., Larson, Kelli L., Morse, Jennifer L., Neill, Christopher, Nelson, Kristen C., O'Neil-Dunne, Jarlath, Ogden, Laura A., Pataki, Diane E., Polsky, Colin, Chowdhury, Rinku Roy Year: 2014 Earth's surface is rapidly urbanizing, resulting in dramatic changes in the abundance, distribution and character of surface water features in urban landscapes. However,the scope and consequences of surface water redistribution at broad spatialscales are not well understood. We hypothesized that urbanization would lead to convergent surface water abundance and distribution: in other words, cities will gain or lose water such that they become more similar to each other than are their surrounding natural landscapes. Using a database of more than 1 million water bodies and 1 million km of streams, we compared the surface water of 100 US cities with their surrounding undeveloped land. We evaluated differences in areal ( A) and numeric densities ( N) of water bodies (lakes, wetlands, and so on), the morphological characteristics of water bodies (size), and the density ( D) of surface flow channels (that is, streams and rivers). The variance of urban A, N, and D across the 100 MSAs decreased, by 89, 25, and 71%, respectively, compared to undeveloped land. These data show that many cities are surface water poor relative to undeveloped land; however, in drier landscapesurbanization increases the occurrence of surface water. This convergence pattern strengthened with development intensity, such that high intensityurban development had an areal water body density 98% less than undeveloped lands. Urbanization appears to drive the convergence of hydrological features across the US, such that surface water distributions of cities are more similar to each other than to their surrounding landscapes. Close

• 45. [Article] Hydrogeologic Characterization of Dutch Canyon, Scappoose, Oregon

  Dutch Canyon is located directly west of the City of Scappoose in Columbia County Oregon. This area is proximate to Highway 30, a major access corridor to downtown Portland, and is experiencing a population ...

  Citation × Citation Citation Abstract Copy Title: Hydrogeologic Characterization of Dutch Canyon, Scappoose, Oregon Author: Wagner, Derrick Lee Year: 2013 Dutch Canyon is located directly west of the City of Scappoose in Columbia County Oregon. This area is proximate to Highway 30, a major access corridor to downtown Portland, and is experiencing a population increase, which is expected to continue and likely accelerate. As a result, there is growing pressure on water resources. Individual and community efforts to utilize groundwater resources have been hampered by generally poor groundwater yields and water quality concerns outside of the Columbia River corridor and a lack of published hydrogeologic information for the region. The intent of this study is to identify the water-bearing units present in Dutch Canyon and to characterize water quality within these units. The physical hydrogeology of Dutch Canyon was assessed mainly through the collation of 196 local well reports that contained lithologic information from which individual hydrostratigraphic units were identified and characterized. Hydraulic parameters for individual units were estimated using pump rates and drawdowns provided in select well reports. Water quality for the units identified was assessed through the collection of 48 samples of well, spring, and stream water from Dutch Canyon. Measurements of pH, specific conductivity, temperature, dissolved oxygen, reduction potential, and alkalinity were recorded in the field and samples were analyzed for major ions, arsenic, and stable isotopes. The major water-bearing units of Dutch Canyon were separated into five physically distinct hydrostratigrapic units: the lower, middle, and upper units of the sedimentary Lower Miocene Scappoose Formation, and the Wapshilla Ridge and Ortley members of the Lower to Middle Miocene Grande Ronde Basalt. Groundwater flow likely occurs in discrete, relatively thin (~2- to 10-m thick) zones within the Grand Ronde Basalt members. These units only occur along the slopes and ridges of Dutch Canyon west of the Portland Hills Fault, which parallels the eastern margin of the study area. The Scappoose Formation units contain clay- and silt-rich layers and lenses that limit the useable aquifer volume and vertical movement of groundwaters. In general, all hydrostratrigraphic units east of the Portland Hills Fault have low transmissivities and water wells completed in each of them are commonly low- yielding wells, though there are some exceptions. Geochemically, the lower and middle units of the Scappoose Formation were similar to one another with many wells yielding groundwater with high total dissolved solids (TDS) contents (mean TDS = 330 mg L-1; n = 27). Nearly 20% of the wells sampled that were screened in these units (5 of 27) yielded groundwater that exceeded the U.S. Environmental Protection Agency's National Secondary (non-enforceable) Drinking Water Regulation standard of 500 mg L-1 TDS. The upper unit of the Scappoose Formation and the overlying Grande Ronde Basalt members generally yield water with lower TDS contents (mean < 200 mg L-1; maximum = 342 mg L-1; n = 20). Groundwater resources in Dutch Canyon are limited and low well yields are common. The primary water quality concern is saline water, which is generally found in the lower and middle units of the Scappoose Formation near the valley floor. Low recharge rates determined from hydrograph analysis of stream discharge measurements are consistent with the geology and steep terrain of the area and further limit the available groundwater and the degree of flushing of what may be connate waters in the deeper units. Title: Hydrogeologic Characterization of Dutch Canyon, Scappoose, Oregon Author: Wagner, Derrick Lee Year: 2013 Dutch Canyon is located directly west of the City of Scappoose in Columbia County Oregon. This area is proximate to Highway 30, a major access corridor to downtown Portland, and is experiencing a population increase, which is expected to continue and likely accelerate. As a result, there is growing pressure on water resources. Individual and community efforts to utilize groundwater resources have been hampered by generally poor groundwater yields and water quality concerns outside of the Columbia River corridor and a lack of published hydrogeologic information for the region. The intent of this study is to identify the water-bearing units present in Dutch Canyon and to characterize water quality within these units. The physical hydrogeology of Dutch Canyon was assessed mainly through the collation of 196 local well reports that contained lithologic information from which individual hydrostratigraphic units were identified and characterized. Hydraulic parameters for individual units were estimated using pump rates and drawdowns provided in select well reports. Water quality for the units identified was assessed through the collection of 48 samples of well, spring, and stream water from Dutch Canyon. Measurements of pH, specific conductivity, temperature, dissolved oxygen, reduction potential, and alkalinity were recorded in the field and samples were analyzed for major ions, arsenic, and stable isotopes. The major water-bearing units of Dutch Canyon were separated into five physically distinct hydrostratigrapic units: the lower, middle, and upper units of the sedimentary Lower Miocene Scappoose Formation, and the Wapshilla Ridge and Ortley members of the Lower to Middle Miocene Grande Ronde Basalt. Groundwater flow likely occurs in discrete, relatively thin (~2- to 10-m thick) zones within the Grand Ronde Basalt members. These units only occur along the slopes and ridges of Dutch Canyon west of the Portland Hills Fault, which parallels the eastern margin of the study area. The Scappoose Formation units contain clay- and silt-rich layers and lenses that limit the useable aquifer volume and vertical movement of groundwaters. In general, all hydrostratrigraphic units east of the Portland Hills Fault have low transmissivities and water wells completed in each of them are commonly low- yielding wells, though there are some exceptions. Geochemically, the lower and middle units of the Scappoose Formation were similar to one another with many wells yielding groundwater with high total dissolved solids (TDS) contents (mean TDS = 330 mg L-1; n = 27). Nearly 20% of the wells sampled that were screened in these units (5 of 27) yielded groundwater that exceeded the U.S. Environmental Protection Agency's National Secondary (non-enforceable) Drinking Water Regulation standard of 500 mg L-1 TDS. The upper unit of the Scappoose Formation and the overlying Grande Ronde Basalt members generally yield water with lower TDS contents (mean < 200 mg L-1; maximum = 342 mg L-1; n = 20). Groundwater resources in Dutch Canyon are limited and low well yields are common. The primary water quality concern is saline water, which is generally found in the lower and middle units of the Scappoose Formation near the valley floor. Low recharge rates determined from hydrograph analysis of stream discharge measurements are consistent with the geology and steep terrain of the area and further limit the available groundwater and the degree of flushing of what may be connate waters in the deeper units. Close

• 46. [Article] Hydrogeologic Investigation of a Pumice Aquifer, Fremont/Winema National Forest, Oregon

  The middle Holocene cataclysmic eruption of Mount Mazama blanketed Walker Rim, in south central Oregon, with 270 cm to 300 cm of pumice, causing capture of surface water systems by groundwater, stream ...

  Citation × Citation Citation Abstract Copy Title: Hydrogeologic Investigation of a Pumice Aquifer, Fremont/Winema National Forest, Oregon Author: Weatherford, Jonathan Michael Year: 2015 The middle Holocene cataclysmic eruption of Mount Mazama blanketed Walker Rim, in south central Oregon, with 270 cm to 300 cm of pumice, causing capture of surface water systems by groundwater, stream relocation, and the formation of biologically diverse fens and seasonal wetlands. The pumice aquifer at Round Meadow, an 8.6 km2 basin, hosts both a fen and seasonally ponded wetlands. The Round Meadow watershed lies within a closed basin between the upper Klamath and Deschutes river basins. As the highest meadow at Walker Rim, it is a relatively well-constrained system to study the effects of hydrological disruption. A water budget was calculated for the basin, hydraulic conductivity was evaluated for the three main sediment layers in the meadow, recharge sources and evaporative trends were studied using stable isotope analysis, and aquifer residence times were estimated using CFC tracer water age dating. Water year 2014 was a drought year and observation of the system under stressed conditions allowed discrimination of four independently functioning components of the hydrogeologic system. These were the meadow, which is by far the largest component in terms of water storage, the fen where iron cementation and up to 1 m of peat holds water in a berm above the meadow, three springs which are sourced from deeper groundwater hosted in the bedrock which underlies the pumice deposit, and the outflow area. In all cases, the aquifer material is pumice, but the influence of the pre-eruption landscape and post-eruption modifications of the aquifer material have resulted in partial isolation of the components. The water budget analysis indicated that the basin lost 44 cm of water storage during WY 2014. Hydraulic conductivity values of 1x10-6, 2x10-2, and 4x10-5 cm/s, were determined for the diatomaceous silt underlying the pumice, the Plinian pumice fall aquifer, and for the diatomaceous silt overlying the pumice, respectively. The pumice is characterized as a perched, weakly confined aquifer and residence times in the pumice are much longer (decades) than for water near the surface of the meadow. Water discharging at the springs is isotopically different (lighter) than either the surface water or groundwater in the pumice aquifer. The fen at Round Meadow appears dependent on seasonal precipitation to recharge water, and responds to fluctuations in annual precipitation. The wetland meadows are volumetrically the main water-storing features at Round Meadow, and these are not homogenous features, but a combination of discrete components. Title: Hydrogeologic Investigation of a Pumice Aquifer, Fremont/Winema National Forest, Oregon Author: Weatherford, Jonathan Michael Year: 2015 The middle Holocene cataclysmic eruption of Mount Mazama blanketed Walker Rim, in south central Oregon, with 270 cm to 300 cm of pumice, causing capture of surface water systems by groundwater, stream relocation, and the formation of biologically diverse fens and seasonal wetlands. The pumice aquifer at Round Meadow, an 8.6 km2 basin, hosts both a fen and seasonally ponded wetlands. The Round Meadow watershed lies within a closed basin between the upper Klamath and Deschutes river basins. As the highest meadow at Walker Rim, it is a relatively well-constrained system to study the effects of hydrological disruption. A water budget was calculated for the basin, hydraulic conductivity was evaluated for the three main sediment layers in the meadow, recharge sources and evaporative trends were studied using stable isotope analysis, and aquifer residence times were estimated using CFC tracer water age dating. Water year 2014 was a drought year and observation of the system under stressed conditions allowed discrimination of four independently functioning components of the hydrogeologic system. These were the meadow, which is by far the largest component in terms of water storage, the fen where iron cementation and up to 1 m of peat holds water in a berm above the meadow, three springs which are sourced from deeper groundwater hosted in the bedrock which underlies the pumice deposit, and the outflow area. In all cases, the aquifer material is pumice, but the influence of the pre-eruption landscape and post-eruption modifications of the aquifer material have resulted in partial isolation of the components. The water budget analysis indicated that the basin lost 44 cm of water storage during WY 2014. Hydraulic conductivity values of 1x10-6, 2x10-2, and 4x10-5 cm/s, were determined for the diatomaceous silt underlying the pumice, the Plinian pumice fall aquifer, and for the diatomaceous silt overlying the pumice, respectively. The pumice is characterized as a perched, weakly confined aquifer and residence times in the pumice are much longer (decades) than for water near the surface of the meadow. Water discharging at the springs is isotopically different (lighter) than either the surface water or groundwater in the pumice aquifer. The fen at Round Meadow appears dependent on seasonal precipitation to recharge water, and responds to fluctuations in annual precipitation. The wetland meadows are volumetrically the main water-storing features at Round Meadow, and these are not homogenous features, but a combination of discrete components. Close

• 47. [Image] Modeling Heat and Mass Transfer at the Mesa Geothermal Anomaly, Imperial Valley, California. Final Project Report

  	The geothermal reservoir modeling effort at the University of Colorado is reviewed briefly. Technical accomplishments during the final funding period 1 April 1978 to 30 November 1978 are described. It ...
  	Citation × Citation Citation Abstract Copy Title: Modeling Heat and Mass Transfer at the Mesa Geothermal Anomaly, Imperial Valley, California. Final Project Report Author: Kassoy, D.R. Year: 1979 The geothermal reservoir modeling effort at the University of Colorado is reviewed briefly. Technical accomplishments during the final funding period 1 April 1978 to 30 November 1978 are described. It is concluded that a physically viable mathematical model of an unexploited geothermal system can be constructed in terms of the fault zone controlled charging of the thermally active section of a reservoir Title: Modeling Heat and Mass Transfer at the Mesa Geothermal Anomaly, Imperial Valley, California. Final Project Report Author: Kassoy, D.R. Year: 1979 The geothermal reservoir modeling effort at the University of Colorado is reviewed briefly. Technical accomplishments during the final funding period 1 April 1978 to 30 November 1978 are described. It is concluded that a physically viable mathematical model of an unexploited geothermal system can be constructed in terms of the fault zone controlled charging of the thermally active section of a reservoir Close

• 48. [Article] Hydrogeology of Pumice-Hosted Fens in the Winema-Fremont National Forest, Oregon, USA

  Subaerial fallout from the Holocene eruption of Mount Mazama in the Oregon Cascade Range was deposited upon relatively low permeability volcanic and volcaniclastic bedrock and regolith. In the Walker Rim ...

  Citation × Citation Citation Abstract Copy Title: Hydrogeology of Pumice-Hosted Fens in the Winema-Fremont National Forest, Oregon, USA Author: Cummings, Michael L., Weatherford, Jonathan Michael, Mowbray, Leslie A Year: 2014 Subaerial fallout from the Holocene eruption of Mount Mazama in the Oregon Cascade Range was deposited upon relatively low permeability volcanic and volcaniclastic bedrock and regolith. In the Walker Rim study area, erosion by ephemeral streams shortly after the eruption disrupted the lateral continuity of the 270 to 300 cm-thick pumice deposit. Co-evolution of the surface- and ground-water systems in a low-relief, low-slope landscape allowed diffuse groundwater discharge from the banks of the evolving stream system. Accumulation of organic material from groundwater dependent ecosystems at these sites of discharge allowed peat deposits to form on gently sloping erosion surfaces cut into the pumice deposit. Following early stream incision, fine-grained, silt-rich deposits accumulated in valleys and contributed permeability barriers to the lateral migration of water in the pumice aquifer. Fens discharge from the pumice aquifer through gently sloping surfaces patterned after the slope of the erosion surface cut into the pumice deposit and overlain by approximately 1 m of peat on the sloping surface and alluvium or iron-cemented pumice overlain by alluvium at the toe of the slope. The predominant source of groundwater is snowmelt which infiltrates the pumice deposit during the freshet. However, shallow groundwater flow also takes place along permeable pathways in bedrock units. Locally, low volume discharge takes place along faults. The snowmelt-dependent hydrologic system that supports the fens of the Walker Rim study area occurs at elevations primarily above 1585 m. Title: Hydrogeology of Pumice-Hosted Fens in the Winema-Fremont National Forest, Oregon, USA Author: Cummings, Michael L., Weatherford, Jonathan Michael, Mowbray, Leslie A Year: 2014 Subaerial fallout from the Holocene eruption of Mount Mazama in the Oregon Cascade Range was deposited upon relatively low permeability volcanic and volcaniclastic bedrock and regolith. In the Walker Rim study area, erosion by ephemeral streams shortly after the eruption disrupted the lateral continuity of the 270 to 300 cm-thick pumice deposit. Co-evolution of the surface- and ground-water systems in a low-relief, low-slope landscape allowed diffuse groundwater discharge from the banks of the evolving stream system. Accumulation of organic material from groundwater dependent ecosystems at these sites of discharge allowed peat deposits to form on gently sloping erosion surfaces cut into the pumice deposit. Following early stream incision, fine-grained, silt-rich deposits accumulated in valleys and contributed permeability barriers to the lateral migration of water in the pumice aquifer. Fens discharge from the pumice aquifer through gently sloping surfaces patterned after the slope of the erosion surface cut into the pumice deposit and overlain by approximately 1 m of peat on the sloping surface and alluvium or iron-cemented pumice overlain by alluvium at the toe of the slope. The predominant source of groundwater is snowmelt which infiltrates the pumice deposit during the freshet. However, shallow groundwater flow also takes place along permeable pathways in bedrock units. Locally, low volume discharge takes place along faults. The snowmelt-dependent hydrologic system that supports the fens of the Walker Rim study area occurs at elevations primarily above 1585 m. Close

• 49. [Article] Continuous Deflection Separation of Stormwater Particulates

  Capture of stormwater particulate matter is of concern to watershed managers trying to meet water quality guidelines by removing toxics associated with particulates from natural water bodies. A laboratory ...

  Citation × Citation Citation Abstract Copy Title: Continuous Deflection Separation of Stormwater Particulates Author: Schwarz, Tracy S., Wells, Scott A. Year: 1999 Capture of stormwater particulate matter is of concern to watershed managers trying to meet water quality guidelines by removing toxics associated with particulates from natural water bodies. A laboratory investigation into particle removal efficiency of a prototype Continuous Deflective Separation (CDS) device was made in the laboratory. Particle size distributions were obtained for roadway drainage surfaces. These distributions were used to assess the predicted performance of a CDS unit in the field. Flow rates in the laboratory tests ranged from 125 GPM (7.9 l/s) to 270 GPM (17.0 l/s). Screen sizes used for testing were 1200 m and 2400 m. Using four different sand types and the two screen sizes, particle capture rates were determined for the CDS unit. Internal velocities were measured at seventy-two measuring positions within the main chamber of the CDS unit. At 270 GPM capture rates based on particle size ranged from 12% to 100% with the 2400 m screen, and 22% to 100% with the 1200 m screen. Cumulative mass capture rates were 73% and 70% for the 1200 m and 2400 m screens, respectively, at 270 gpm and 84% at 125 gpm for the given particle distribution used. Title: Continuous Deflection Separation of Stormwater Particulates Author: Schwarz, Tracy S., Wells, Scott A. Year: 1999 Capture of stormwater particulate matter is of concern to watershed managers trying to meet water quality guidelines by removing toxics associated with particulates from natural water bodies. A laboratory investigation into particle removal efficiency of a prototype Continuous Deflective Separation (CDS) device was made in the laboratory. Particle size distributions were obtained for roadway drainage surfaces. These distributions were used to assess the predicted performance of a CDS unit in the field. Flow rates in the laboratory tests ranged from 125 GPM (7.9 l/s) to 270 GPM (17.0 l/s). Screen sizes used for testing were 1200 m and 2400 m. Using four different sand types and the two screen sizes, particle capture rates were determined for the CDS unit. Internal velocities were measured at seventy-two measuring positions within the main chamber of the CDS unit. At 270 GPM capture rates based on particle size ranged from 12% to 100% with the 2400 m screen, and 22% to 100% with the 1200 m screen. Cumulative mass capture rates were 73% and 70% for the 1200 m and 2400 m screens, respectively, at 270 gpm and 84% at 125 gpm for the given particle distribution used. Close

• 50. [Article] The Influence of Floodplain Restoration on Flow and Sediment Dynamics in an Urban River

  A study of floodplain sedimentation on a recently restored floodplain is presented. This study uses a two-dimensional hydro-morphodynamic model for predicting flow and suspended-sediment dynamics in the ...

  Citation × Citation Citation Abstract Copy Title: The Influence of Floodplain Restoration on Flow and Sediment Dynamics in an Urban River Author: Ahilan, Sangaralingam, Guan, Mingfu, Sleigh, Andrew, Wright, Nigel G., Chang, Heejun Year: 2016 A study of floodplain sedimentation on a recently restored floodplain is presented. This study uses a two-dimensional hydro-morphodynamic model for predicting flow and suspended-sediment dynamics in the downstream of Johnson Creek, the East Lents reach, where the bank of the river has been reconfigured to reconnect to a restored floodplain on a 0.26 km2 (26-ha) site. The simulation scenarios include 10-, 50-, 100- and 500-year event-based deposition modelling of flood events and long-term modelling using the 64 historical flood events between 1941 and 2014. Simulation results showed that the restored floodplain significantly attenuates the upstream flood peak by up to 25% at the downstream. Results also indicated that approximately 20%–30% of sediment from the upstream is deposited on the East Lents floodplain. Furthermore, deposited sediment over the simulated period (1941–2014) is approximately 0.1% of the basin's flood storage capacity; however, the reduction in the storage does not offset the overall flood resilience impact of the flood basin. The sediment conservation at the East Lents flood basin as predicted by the model reduces the annual sediment loading of the Johnson Creek by 1% at the confluence with Willamette River, providing both improved water quality and flood resilience further downstream. Title: The Influence of Floodplain Restoration on Flow and Sediment Dynamics in an Urban River Author: Ahilan, Sangaralingam, Guan, Mingfu, Sleigh, Andrew, Wright, Nigel G., Chang, Heejun Year: 2016 A study of floodplain sedimentation on a recently restored floodplain is presented. This study uses a two-dimensional hydro-morphodynamic model for predicting flow and suspended-sediment dynamics in the downstream of Johnson Creek, the East Lents reach, where the bank of the river has been reconfigured to reconnect to a restored floodplain on a 0.26 km2 (26-ha) site. The simulation scenarios include 10-, 50-, 100- and 500-year event-based deposition modelling of flood events and long-term modelling using the 64 historical flood events between 1941 and 2014. Simulation results showed that the restored floodplain significantly attenuates the upstream flood peak by up to 25% at the downstream. Results also indicated that approximately 20%–30% of sediment from the upstream is deposited on the East Lents floodplain. Furthermore, deposited sediment over the simulated period (1941–2014) is approximately 0.1% of the basin's flood storage capacity; however, the reduction in the storage does not offset the overall flood resilience impact of the flood basin. The sediment conservation at the East Lents flood basin as predicted by the model reduces the annual sediment loading of the Johnson Creek by 1% at the confluence with Willamette River, providing both improved water quality and flood resilience further downstream. Close