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• 1. [Article] Emerging Pollutants in the Columbia River: A Simple Assessment of Nonpoint Source Zones

  Water quality modeling in the Columbia River Basin was conducted at the confluence of the Willamette and Columbia Rivers, river mile 101. The study area for this research consists of Sauvie Island, OR, ...

  Citation × Citation Citation Abstract Copy Title: Emerging Pollutants in the Columbia River: A Simple Assessment of Nonpoint Source Zones Author: Kim, Chulgi Year: 2017 Water quality modeling in the Columbia River Basin was conducted at the confluence of the Willamette and Columbia Rivers, river mile 101. The study area for this research consists of Sauvie Island, OR, and the surrounding areas of Vancouver, WA. Analysis of the region’s watershed and simple hydrologic calculations allowed for estimates of potential sources contributing to PBDEs in the Columbia River along river mile 101. This research included assessment of rainfall patterns and peak discharge rates in the areas along the rivers. A simple model of overland flow for the watershed was applied to estimate the area’s contribution to overall flow in the Columbia River. Potential impacts and possible sources for emerging pollutants in the Columbia River at river mile 101 were inferred from this analysis. Title: Emerging Pollutants in the Columbia River: A Simple Assessment of Nonpoint Source Zones Author: Kim, Chulgi Year: 2017 Water quality modeling in the Columbia River Basin was conducted at the confluence of the Willamette and Columbia Rivers, river mile 101. The study area for this research consists of Sauvie Island, OR, and the surrounding areas of Vancouver, WA. Analysis of the region’s watershed and simple hydrologic calculations allowed for estimates of potential sources contributing to PBDEs in the Columbia River along river mile 101. This research included assessment of rainfall patterns and peak discharge rates in the areas along the rivers. A simple model of overland flow for the watershed was applied to estimate the area’s contribution to overall flow in the Columbia River. Potential impacts and possible sources for emerging pollutants in the Columbia River at river mile 101 were inferred from this analysis. Close

• 2. [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

• 3. [Article] Application of CE-QUAL-W2 on Tigris River in Iraq

  The Tigris River is the eastern member of the two great rivers in Iraq. Two big rivers pass through Iraq, Mesopotamia. Tigris and Euphrates Rivers with their tributaries form a major river system in the ...

  Citation × Citation Citation Abstract Copy Title: Application of CE-QUAL-W2 on Tigris River in Iraq Author: Al-Murib, Muhanned Year: 2014 The Tigris River is the eastern member of the two great rivers in Iraq. Two big rivers pass through Iraq, Mesopotamia. Tigris and Euphrates Rivers with their tributaries form a major river system in the Middle East. Four riparian countries, Turkey, Syria, Iran, and Iraq, share the Tigris River basin area and Iraq has the majority of this basin area. The total length of the Tigris is 1850 km from which 1418 km is within Iraq. A study area of 880 km from Mosul dam to Kut barrage is modeled using a water quality CE-QUAL-W2 model. CE-QUAL-W2 is a two-dimensional (longitudinal and vertical) water quality model developed by the U.S. Army Corps of Engineers and Portland State University. W2 simulates river circulation, stage, vertical and horizontal velocities, water temperature, and a host of water quality constituents. Total dissolved solids (TDS) is the main concern in Iraq because Iraq heavily depends on its water for irrigation purposes. Therefore, this project discusses the implementation of CE-QUAL-W2 model on Tigris River to simulate flow, temperature, and TDS. Title: Application of CE-QUAL-W2 on Tigris River in Iraq Author: Al-Murib, Muhanned Year: 2014 The Tigris River is the eastern member of the two great rivers in Iraq. Two big rivers pass through Iraq, Mesopotamia. Tigris and Euphrates Rivers with their tributaries form a major river system in the Middle East. Four riparian countries, Turkey, Syria, Iran, and Iraq, share the Tigris River basin area and Iraq has the majority of this basin area. The total length of the Tigris is 1850 km from which 1418 km is within Iraq. A study area of 880 km from Mosul dam to Kut barrage is modeled using a water quality CE-QUAL-W2 model. CE-QUAL-W2 is a two-dimensional (longitudinal and vertical) water quality model developed by the U.S. Army Corps of Engineers and Portland State University. W2 simulates river circulation, stage, vertical and horizontal velocities, water temperature, and a host of water quality constituents. Total dissolved solids (TDS) is the main concern in Iraq because Iraq heavily depends on its water for irrigation purposes. Therefore, this project discusses the implementation of CE-QUAL-W2 model on Tigris River to simulate flow, temperature, and TDS. Close

• 4. [Article] Evaluating Global Sensitivity Analysis Methods for Hydrologic Modeling over the Columbia River Basin

  Global Sensitivity Analysis (GSA) approach helps to identify the effectiveness of model parameters or inputs and thus provides essential information about the model performance. The effects of 14 parameters ...

  Citation × Citation Citation Abstract Copy Title: Evaluating Global Sensitivity Analysis Methods for Hydrologic Modeling over the Columbia River Basin Author: Hameed, Maysoun Ayad Year: 2015 Global Sensitivity Analysis (GSA) approach helps to identify the effectiveness of model parameters or inputs and thus provides essential information about the model performance. The effects of 14 parameters and one input (forcing data) of the Sacramento Soil Moisture Accounting (SAC-SMA) model are analyzed by using two GSA methods: Sobol' and Fourier Amplitude Sensitivity Test (FAST). The simulations are carried out over five sub-basins within the Columbia River Basin (CRB) for three different periods: one-year, four-year, and seven-year. The main parameter sensitivities (first-order) and the interactions sensitivities (second-order) are evaluated in this study. Our results show that some hydrological processes are highly affected by the simulation length. In other words, some parameters reveal importance during the short period simulation (e.g. one-year) while other parameters are effective in the long period simulations (e.g. four-year and seven-year). Moreover, the reliability of the sensitivity analysis results is compared based on 1) the agreement between the two sensitivity analysis methods (Sobol' and FAST) in terms of highlighting the same parameters or input as the most influential parameters or input and 2) how the methods are cohered in ranking these sensitive parameters under the same conditions (sub-basins and simulation length). The results show that the coherence between the Sobol' and FAST sensitivity analysis methods. Additionally, it is found that FAST method is sufficient to evaluate the main effects of the model parameters and inputs. This study confirms that the Sobol' and FAST methods are reliable GSA methods that can be applied in different scientific applications. Finally, as a future work, we suggest to study the uncertainty associated with the sensitivity analysis approach regarding the reliability of evaluating different sensitivity analysis methods. Title: Evaluating Global Sensitivity Analysis Methods for Hydrologic Modeling over the Columbia River Basin Author: Hameed, Maysoun Ayad Year: 2015 Global Sensitivity Analysis (GSA) approach helps to identify the effectiveness of model parameters or inputs and thus provides essential information about the model performance. The effects of 14 parameters and one input (forcing data) of the Sacramento Soil Moisture Accounting (SAC-SMA) model are analyzed by using two GSA methods: Sobol' and Fourier Amplitude Sensitivity Test (FAST). The simulations are carried out over five sub-basins within the Columbia River Basin (CRB) for three different periods: one-year, four-year, and seven-year. The main parameter sensitivities (first-order) and the interactions sensitivities (second-order) are evaluated in this study. Our results show that some hydrological processes are highly affected by the simulation length. In other words, some parameters reveal importance during the short period simulation (e.g. one-year) while other parameters are effective in the long period simulations (e.g. four-year and seven-year). Moreover, the reliability of the sensitivity analysis results is compared based on 1) the agreement between the two sensitivity analysis methods (Sobol' and FAST) in terms of highlighting the same parameters or input as the most influential parameters or input and 2) how the methods are cohered in ranking these sensitive parameters under the same conditions (sub-basins and simulation length). The results show that the coherence between the Sobol' and FAST sensitivity analysis methods. Additionally, it is found that FAST method is sufficient to evaluate the main effects of the model parameters and inputs. This study confirms that the Sobol' and FAST methods are reliable GSA methods that can be applied in different scientific applications. Finally, as a future work, we suggest to study the uncertainty associated with the sensitivity analysis approach regarding the reliability of evaluating different sensitivity analysis methods. Close

• 5. [Article] Implementation of a Sediment Transport Model for CE-QUAL-W2

  The CE-QUAL-W2 model, developed by Portland State University, simulates water quality and flow. Recommendations to expand on this model and have it include sediment transport are implemented in this report. ...

  Citation × Citation Citation Abstract Copy Title: Implementation of a Sediment Transport Model for CE-QUAL-W2 Author: Hanna, Rachel Year: 2014 The CE-QUAL-W2 model, developed by Portland State University, simulates water quality and flow. Recommendations to expand on this model and have it include sediment transport are implemented in this report. Existing one-, two-, and three-dimensional models are reviewed and assessed for their sediment transport methodology. A laterally (width) averaged sediment concentration model is developed as an Upwind Center Space Scheme using CE-QUAL-W2 data. The scheme includes a method to calculate scour for sediment concentration and results of the model are shown for a simulated branch of the Spokane River. Title: Implementation of a Sediment Transport Model for CE-QUAL-W2 Author: Hanna, Rachel Year: 2014 The CE-QUAL-W2 model, developed by Portland State University, simulates water quality and flow. Recommendations to expand on this model and have it include sediment transport are implemented in this report. Existing one-, two-, and three-dimensional models are reviewed and assessed for their sediment transport methodology. A laterally (width) averaged sediment concentration model is developed as an Upwind Center Space Scheme using CE-QUAL-W2 data. The scheme includes a method to calculate scour for sediment concentration and results of the model are shown for a simulated branch of the Spokane River. Close

• 6. [Article] Daily Discharge Forecasting Using Least Square Support Vector Regression and Regression Tree

  Prediction of river flow is one of the main issues in the field of water resources management. Because of the complexity of the rainfall-runoff process, data-driven methods have gained increased importance. ...

  Citation × Citation Citation Abstract Copy Title: Daily Discharge Forecasting Using Least Square Support Vector Regression and Regression Tree Author: Sahraei, Shahram, Andalani, Saeed Zare, Zakermoshfegh, Mohammad, Sisakht, Babak Nikeghbal, Talebbeydokhti, Nasser, Moradkhani, Hamid Year: 2015 Prediction of river flow is one of the main issues in the field of water resources management. Because of the complexity of the rainfall-runoff process, data-driven methods have gained increased importance. In the current study, two newly developed models called Least Square Support Vector Regression (LSSVR) and Regression Tree (RT) are used. The LSSVR model is based on the constrained optimization method and applies structural risk minimization in order to yield a general optimized result. Also in the RT, data movement is based on laws discovered in the tree. Both models have been applied to the data in the Kashkan watershed. Variables include (a) recorded precipitation values in the Kashkan watershed stations, and (b) outlet discharge values of one and two previous days. Present discharge is considered as output of the two models. Following that, a sensitivity analysis has been carried out on the input features and less important features has been diminished so that both models have provided better prediction on the data. The final results of both models have been compared. It was found that the LSSVR model has better performance. Finally, the results present these models as a suitable models in river flow forecasting. Title: Daily Discharge Forecasting Using Least Square Support Vector Regression and Regression Tree Author: Sahraei, Shahram, Andalani, Saeed Zare, Zakermoshfegh, Mohammad, Sisakht, Babak Nikeghbal, Talebbeydokhti, Nasser, Moradkhani, Hamid Year: 2015 Prediction of river flow is one of the main issues in the field of water resources management. Because of the complexity of the rainfall-runoff process, data-driven methods have gained increased importance. In the current study, two newly developed models called Least Square Support Vector Regression (LSSVR) and Regression Tree (RT) are used. The LSSVR model is based on the constrained optimization method and applies structural risk minimization in order to yield a general optimized result. Also in the RT, data movement is based on laws discovered in the tree. Both models have been applied to the data in the Kashkan watershed. Variables include (a) recorded precipitation values in the Kashkan watershed stations, and (b) outlet discharge values of one and two previous days. Present discharge is considered as output of the two models. Following that, a sensitivity analysis has been carried out on the input features and less important features has been diminished so that both models have provided better prediction on the data. The final results of both models have been compared. It was found that the LSSVR model has better performance. Finally, the results present these models as a suitable models in river flow forecasting. Close

• 7. [Article] Combined Assimilation of Streamflow and Satellite Soil Moisture with the Particle Filter and Geostatistical Modeling

  Assimilation of satellite soil moisture and streamflow data into a distributed hydrologic model has received increasing attention over the past few years. This study provides a detailed analysis of the ...

  Citation × Citation Citation Abstract Copy Title: Combined Assimilation of Streamflow and Satellite Soil Moisture with the Particle Filter and Geostatistical Modeling Author: Yan, Hongxiang, Moradkhani, Hamid Year: 2016 Assimilation of satellite soil moisture and streamflow data into a distributed hydrologic model has received increasing attention over the past few years. This study provides a detailed analysis of the joint and separate assimilation of streamflow and Advanced Scatterometer (ASCAT) surface soil moisture into a distributed Sacramento Soil Moisture Accounting (SAC-SMA) model, with the use of recently developed particle filter-Markov chain Monte Carlo (PF-MCMC) method. Performance is assessed over the Salt River Watershed in Arizona, which is one of the watersheds without anthropogenic effects in Model Parameter Estimation Experiment (MOPEX). A total of five data assimilation (DA) scenarios are designed and the effects of the locations of streamflow gauges and the ASCAT soil moisture on the predictions of soil moisture and streamflow are assessed. In addition, a geostatistical model is introduced to overcome the significantly biased satellite soil moisture and also discontinuity issue. The results indicate that: (1) solely assimilating outlet streamflow can lead to biased soil moisture estimation; (2) when the study area can only be partially covered by the satellite data, the geostatistical approach can estimate the soil moisture for those uncovered grid cells; (3) joint assimilation of streamflow and soil moisture from geostatistical modeling can further improve the surface soil moisture prediction. This study recommends that the geostatistical model is a helpful tool to aid the remote sensing technique and the hydrologic DA study. Title: Combined Assimilation of Streamflow and Satellite Soil Moisture with the Particle Filter and Geostatistical Modeling Author: Yan, Hongxiang, Moradkhani, Hamid Year: 2016 Assimilation of satellite soil moisture and streamflow data into a distributed hydrologic model has received increasing attention over the past few years. This study provides a detailed analysis of the joint and separate assimilation of streamflow and Advanced Scatterometer (ASCAT) surface soil moisture into a distributed Sacramento Soil Moisture Accounting (SAC-SMA) model, with the use of recently developed particle filter-Markov chain Monte Carlo (PF-MCMC) method. Performance is assessed over the Salt River Watershed in Arizona, which is one of the watersheds without anthropogenic effects in Model Parameter Estimation Experiment (MOPEX). A total of five data assimilation (DA) scenarios are designed and the effects of the locations of streamflow gauges and the ASCAT soil moisture on the predictions of soil moisture and streamflow are assessed. In addition, a geostatistical model is introduced to overcome the significantly biased satellite soil moisture and also discontinuity issue. The results indicate that: (1) solely assimilating outlet streamflow can lead to biased soil moisture estimation; (2) when the study area can only be partially covered by the satellite data, the geostatistical approach can estimate the soil moisture for those uncovered grid cells; (3) joint assimilation of streamflow and soil moisture from geostatistical modeling can further improve the surface soil moisture prediction. This study recommends that the geostatistical model is a helpful tool to aid the remote sensing technique and the hydrologic DA study. Close

• 8. [Article] A Study on the Current State of Contaminants of Concern Research, With a Focus on Biosolids and Regulations

  Wastewater treatment plants are a major source of contaminants of emerging concern, as these facilities are the main receptors of these products via household, commercial, and industrial drains, and transport ...

  Citation × Citation Citation Abstract Copy Title: A Study on the Current State of Contaminants of Concern Research, With a Focus on Biosolids and Regulations Author: Fulton, Maren Year: 2016 Wastewater treatment plants are a major source of contaminants of emerging concern, as these facilities are the main receptors of these products via household, commercial, and industrial drains, and transport via stormwater runoff. Biosolids are composed of numerous constituents, with a number of environmentally persistent and potentially toxic contaminants of emerging concern identified as present in large concentrations. Research is needed to understand the transport and fate mechanisms of these compounds in biosolids. Additionally, this research is needed to determine a new priority framework to regulate CECs, both on the national level and regional levels. Wastewater treatment plant influent and effluent treatment regulations and practices may be improved upon as more knowledge accrues regarding contaminants of emerging concern behavior in the environment. The United States environmental regulatory process is a constant work in progress. Inherited from decades-old public health traditions, environmental regulatory programs arose to address the issues of public health as water and air quality issues surfaced. The Toxic Substances Control Act (TSCA) (15 U.S.C. 2601), enacted in 1976, provided the EPA regulatory authority to protect the environment and consumers’ health against risks posed by chemicals in commerce. TSCA only retroactively addressed chemical hazards, after they had been deemed unsafe and previously unrestricted in the public. A bill to overhaul TSCA, the Frank R. Lautenberg Chemical Safety for the 21st Century Act (House Amendment to the Senate Amendment to H.R. 2576, TSCA Modernization Act of 2015), was passed by the Senate on June 7, 2016 and sent on for President Obama’s signature. The amended law will give the EPA new authority to evaluate the safety of a new chemical before it enters the marketplace. It will also allow EPA to evaluate the safety of chemicals already known to be risks, including chemicals found to persist in the human body and in the environment. The Columbia River is presented as a case study as an example of a significant waterbody with research and regulatory gaps concerning CECs. The Columbia River waterbody was chosen as it represents an important natural resource for which data gaps exist on CEC sources and pathways into the waterbody, and which also does not receive adequate protective regulations under the national regulatory framework. Title: A Study on the Current State of Contaminants of Concern Research, With a Focus on Biosolids and Regulations Author: Fulton, Maren Year: 2016 Wastewater treatment plants are a major source of contaminants of emerging concern, as these facilities are the main receptors of these products via household, commercial, and industrial drains, and transport via stormwater runoff. Biosolids are composed of numerous constituents, with a number of environmentally persistent and potentially toxic contaminants of emerging concern identified as present in large concentrations. Research is needed to understand the transport and fate mechanisms of these compounds in biosolids. Additionally, this research is needed to determine a new priority framework to regulate CECs, both on the national level and regional levels. Wastewater treatment plant influent and effluent treatment regulations and practices may be improved upon as more knowledge accrues regarding contaminants of emerging concern behavior in the environment. The United States environmental regulatory process is a constant work in progress. Inherited from decades-old public health traditions, environmental regulatory programs arose to address the issues of public health as water and air quality issues surfaced. The Toxic Substances Control Act (TSCA) (15 U.S.C. 2601), enacted in 1976, provided the EPA regulatory authority to protect the environment and consumers’ health against risks posed by chemicals in commerce. TSCA only retroactively addressed chemical hazards, after they had been deemed unsafe and previously unrestricted in the public. A bill to overhaul TSCA, the Frank R. Lautenberg Chemical Safety for the 21st Century Act (House Amendment to the Senate Amendment to H.R. 2576, TSCA Modernization Act of 2015), was passed by the Senate on June 7, 2016 and sent on for President Obama’s signature. The amended law will give the EPA new authority to evaluate the safety of a new chemical before it enters the marketplace. It will also allow EPA to evaluate the safety of chemicals already known to be risks, including chemicals found to persist in the human body and in the environment. The Columbia River is presented as a case study as an example of a significant waterbody with research and regulatory gaps concerning CECs. The Columbia River waterbody was chosen as it represents an important natural resource for which data gaps exist on CEC sources and pathways into the waterbody, and which also does not receive adequate protective regulations under the national regulatory framework. Close