Search

Search Results

• 1. [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

• 2. [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

• 3. [Article] Statistical Comparisons of Watershed-Scale Response to Climate Change in Selected Basins across the United States

  In an earlier global climate-change study, air temperature and precipitation data for the entire twenty-first century simulated from five general circulation models were used as input to precalibrated ...

  Citation × Citation Citation Abstract Copy Title: Statistical Comparisons of Watershed-Scale Response to Climate Change in Selected Basins across the United States Author: Risley, John, Moradkhani, Hamid, Hay, Lauren, Markstrom, Steve Year: 2011 In an earlier global climate-change study, air temperature and precipitation data for the entire twenty-first century simulated from five general circulation models were used as input to precalibrated watershed models for 14 selected basins across the United States. Simulated daily streamflow and energy output from the watershed models were used to compute a range of statistics. With a side-by-side comparison of the statistical analyses for the 14 basins, regional climatic and hydrologic trends over the twenty-first century could be qualitatively identified. Low-flow statistics (95% exceedance, 7-day mean annual minimum, and summer mean monthly streamflow) decreased for almost all basins. Annual maximum daily streamflow also decreased in all the basins, except for all four basins in California and the Pacific Northwest. An analysis of the supply of available energy and water for the basins indicated that ratios of evaporation to precipitation and potential evapotranspiration to precipitation for most of the basins will increase. Probability density functions (PDFs) were developed to assess the uncertainty and multimodality in the impact of climate change on mean annual streamflow variability. Kolmogorov?Smirnov tests showed significant differences between the beginning and ending twenty-first-century PDFs for most of the basins, with the exception of four basins that are located in the western United States. Almost none of the basin PDFs were normally distributed, and two basins in the upper Midwest had PDFs that were extremely dispersed and skewed. Title: Statistical Comparisons of Watershed-Scale Response to Climate Change in Selected Basins across the United States Author: Risley, John, Moradkhani, Hamid, Hay, Lauren, Markstrom, Steve Year: 2011 In an earlier global climate-change study, air temperature and precipitation data for the entire twenty-first century simulated from five general circulation models were used as input to precalibrated watershed models for 14 selected basins across the United States. Simulated daily streamflow and energy output from the watershed models were used to compute a range of statistics. With a side-by-side comparison of the statistical analyses for the 14 basins, regional climatic and hydrologic trends over the twenty-first century could be qualitatively identified. Low-flow statistics (95% exceedance, 7-day mean annual minimum, and summer mean monthly streamflow) decreased for almost all basins. Annual maximum daily streamflow also decreased in all the basins, except for all four basins in California and the Pacific Northwest. An analysis of the supply of available energy and water for the basins indicated that ratios of evaporation to precipitation and potential evapotranspiration to precipitation for most of the basins will increase. Probability density functions (PDFs) were developed to assess the uncertainty and multimodality in the impact of climate change on mean annual streamflow variability. Kolmogorov?Smirnov tests showed significant differences between the beginning and ending twenty-first-century PDFs for most of the basins, with the exception of four basins that are located in the western United States. Almost none of the basin PDFs were normally distributed, and two basins in the upper Midwest had PDFs that were extremely dispersed and skewed. Close

• 4. [Article] City of Gresham Stormwater Retrofit Master Plan

  The Stormwater Retrofit Master Plan identifies more than 50 stormwater retrofit project opportunities across three watersheds in the City of Gresham. The retrofit projects are prioritized in a scoring ...

  Citation × Citation Citation Abstract Copy Title: City of Gresham Stormwater Retrofit Master Plan Author: Huntsinger, Teresa F Year: 2017 The Stormwater Retrofit Master Plan identifies more than 50 stormwater retrofit project opportunities across three watersheds in the City of Gresham. The retrofit projects are prioritized in a scoring system to evaluate the costs and benefits of diverse project sizes and types. Project types range from bioswales and planters in city parking lots and along arterial roads, to regional end-of-pipe facilities and retrofits of existing detention ponds. Top projects will move forward for further assessment, design and construction, helping the city achieve its water quality improvement goals. The scoring system may be used to evaluate additional projects in the future. Title: City of Gresham Stormwater Retrofit Master Plan Author: Huntsinger, Teresa F Year: 2017 The Stormwater Retrofit Master Plan identifies more than 50 stormwater retrofit project opportunities across three watersheds in the City of Gresham. The retrofit projects are prioritized in a scoring system to evaluate the costs and benefits of diverse project sizes and types. Project types range from bioswales and planters in city parking lots and along arterial roads, to regional end-of-pipe facilities and retrofits of existing detention ponds. Top projects will move forward for further assessment, design and construction, helping the city achieve its water quality improvement goals. The scoring system may be used to evaluate additional projects in the future. Close

• 5. [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

• 6. [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

• 7. [Article] Potential Impacts of Climate Change on Flood-Induced Travel Disruptions: A Case Study of Portland, Oregon, USA

  This study investigated potential impacts of climate change on travel disruption resulting from road closures in two urban watersheds in the Portland, Oregon, metropolitan area. We used ensemble climate ...

  Citation × Citation Citation Abstract Copy Title: Potential Impacts of Climate Change on Flood-Induced Travel Disruptions: A Case Study of Portland, Oregon, USA Author: Chang, Heejun, Lafrenz, Martin, Jung, Il-won, Figliozzi, Miguel, Platman, Deena, Pederson, Cindy Year: 2010 This study investigated potential impacts of climate change on travel disruption resulting from road closures in two urban watersheds in the Portland, Oregon, metropolitan area. We used ensemble climate change scenarios, a hydrologic model, a stream channel survey, a hydraulic model, and a travel forecast model to develop an integrated impact assessment method. High-resolution climate change scenarios are based on the combinations of two emission scenarios and eight general circulation models. The Precipitation-Runoff Modeling System was calibrated and validated for the historical period of 1988 and 2006 and simulated for determining the probability of floods for 2020 through 2049. We surveyed stream cross-sections at five road crossings for stream channel geometry and determined flood water surface elevations using the Hydrologic Engineering Centers River Analysis System (HEC-RAS) model. Four of the surveyed bridges and roadways were lower in elevation than the current 100-year flood water surface elevation, leading to relatively frequent nuisance flooding. These roadway flooding events will become more frequent under some climate change scenarios in the future, but climate change impacts will depend on local geomorphic conditions. Whereas vehicle miles traveled was not significantly affected by road closure, vehicle hours delay demonstrated a greater impact from road closures, increasing by 10 percent in the Fanno Creek area. Our research demonstrated the usefulness of the integration of top-down and bottom-up approaches in climate change impact assessment and the need for spatially explicit modeling and participatory planning in flood management and transportation planning under increasing climate uncertainty. Title: Potential Impacts of Climate Change on Flood-Induced Travel Disruptions: A Case Study of Portland, Oregon, USA Author: Chang, Heejun, Lafrenz, Martin, Jung, Il-won, Figliozzi, Miguel, Platman, Deena, Pederson, Cindy Year: 2010 This study investigated potential impacts of climate change on travel disruption resulting from road closures in two urban watersheds in the Portland, Oregon, metropolitan area. We used ensemble climate change scenarios, a hydrologic model, a stream channel survey, a hydraulic model, and a travel forecast model to develop an integrated impact assessment method. High-resolution climate change scenarios are based on the combinations of two emission scenarios and eight general circulation models. The Precipitation-Runoff Modeling System was calibrated and validated for the historical period of 1988 and 2006 and simulated for determining the probability of floods for 2020 through 2049. We surveyed stream cross-sections at five road crossings for stream channel geometry and determined flood water surface elevations using the Hydrologic Engineering Centers River Analysis System (HEC-RAS) model. Four of the surveyed bridges and roadways were lower in elevation than the current 100-year flood water surface elevation, leading to relatively frequent nuisance flooding. These roadway flooding events will become more frequent under some climate change scenarios in the future, but climate change impacts will depend on local geomorphic conditions. Whereas vehicle miles traveled was not significantly affected by road closure, vehicle hours delay demonstrated a greater impact from road closures, increasing by 10 percent in the Fanno Creek area. Our research demonstrated the usefulness of the integration of top-down and bottom-up approaches in climate change impact assessment and the need for spatially explicit modeling and participatory planning in flood management and transportation planning under increasing climate uncertainty. Close