Search

Search Results

• 1. [Article] Calibration and verification of HSPF model for Tualatin River Basin Water Quality

  The Tualatin River Basin is located in the Washington County, Oregon. The river was detected having high chlorophyll a concentration and low dissolved oxygen concentration during summer time, which violated ...

  Citation × Citation Citation Abstract Copy Title: Calibration and verification of HSPF model for Tualatin River Basin Water Quality Author: Tang, Fei The Tualatin River Basin is located in the Washington County, Oregon. The river was detected having high chlorophyll a concentration and low dissolved oxygen concentration during summer time, which violated DEQ water quality standards. A mathematical model (HSPF) was used to simulate physical, chemical and biological processes in the basin and to evaluate the effect of the 'best management practice' (BMP) strategy on improving water quality of the basin. Calibration of the model was focused on water temperature, total suspended solids, dissolved oxygen, dissolved ammonia, dissolved nitrate, dissolved phosphate, and chlorophyll a. Comparison against observed data (1990) showed that the model predictions were accurate for most of the constituents. After verification, the model was used to evaluate the strategy of the Best Management Practice (BMP) on the agricultural land at Gales Creek basin, a major sub-basin of the study area. The results showed that the effect of BMP on nutrients loading from land segment is not significant at Gales Creek. Title: Calibration and verification of HSPF model for Tualatin River Basin Water Quality Author: Tang, Fei The Tualatin River Basin is located in the Washington County, Oregon. The river was detected having high chlorophyll a concentration and low dissolved oxygen concentration during summer time, which violated DEQ water quality standards. A mathematical model (HSPF) was used to simulate physical, chemical and biological processes in the basin and to evaluate the effect of the 'best management practice' (BMP) strategy on improving water quality of the basin. Calibration of the model was focused on water temperature, total suspended solids, dissolved oxygen, dissolved ammonia, dissolved nitrate, dissolved phosphate, and chlorophyll a. Comparison against observed data (1990) showed that the model predictions were accurate for most of the constituents. After verification, the model was used to evaluate the strategy of the Best Management Practice (BMP) on the agricultural land at Gales Creek basin, a major sub-basin of the study area. The results showed that the effect of BMP on nutrients loading from land segment is not significant at Gales Creek. Close

• 2. [Article] MidCoast sixth field watershed assessment : final report

  The study area for this assessment is composed of the Alsea, Salmon, Siletz, Yachats, and Yaquina River watersheds and those watersheds that drain directly to the ocean between Cascade Head and Cape Creek ...

  Citation × Citation Citation Abstract Copy Title: MidCoast sixth field watershed assessment : final report Author: Garono, Ralph J., Brophy, Laura The study area for this assessment is composed of the Alsea, Salmon, Siletz, Yachats, and Yaquina River watersheds and those watersheds that drain directly to the ocean between Cascade Head and Cape Creek at Heceta Head (Ocean Tributaries). Wherever possible, 1:24,000 uniform scale geographic information system (GIS) data that covered the entire study area were used in this assessment. Goals of this study include, (1) a summary of current conditions for each 6th field watershed; and (2) recommendations for monitoring and management actions for prioritized 6th field watersheds. Title: MidCoast sixth field watershed assessment : final report Author: Garono, Ralph J., Brophy, Laura The study area for this assessment is composed of the Alsea, Salmon, Siletz, Yachats, and Yaquina River watersheds and those watersheds that drain directly to the ocean between Cascade Head and Cape Creek at Heceta Head (Ocean Tributaries). Wherever possible, 1:24,000 uniform scale geographic information system (GIS) data that covered the entire study area were used in this assessment. Goals of this study include, (1) a summary of current conditions for each 6th field watershed; and (2) recommendations for monitoring and management actions for prioritized 6th field watersheds. Close

• 3. [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

• 4. [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

• 5. [Article] Climate change impacts on maritime mountain snowpack in the Oregon Cascades

  This is the publisher’s final pdf. The published article is copyrighted by Copernicus Publications and can be found at: http://publications.copernicus.org/.

  Citation × Citation Citation Abstract Copy Title: Climate change impacts on maritime mountain snowpack in the Oregon Cascades Author: Sproles, E. A., Nolin, A.W., Rittger, K., Painter, T. H. This is the publisher’s final pdf. The published article is copyrighted by Copernicus Publications and can be found at: http://publications.copernicus.org/. Title: Climate change impacts on maritime mountain snowpack in the Oregon Cascades Author: Sproles, E. A., Nolin, A.W., Rittger, K., Painter, T. H. This is the publisher’s final pdf. The published article is copyrighted by Copernicus Publications and can be found at: http://publications.copernicus.org/. Close