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• 51. [Article] A Landscape Approach to Determining and Predicting Juvenile Coho Salmon (<i>Oncorhynchus kisutch</i>) Movement Timing and Growth Patterns Prior to Ocean Entry

  Coho salmon (Oncorhynchus kisutch) rely on unique habitats during the winter season, which may dictate how much individuals may grow and when migration from freshwater rearing habitat to the ocean occurs. ...

  Citation × Citation Citation Abstract Copy Title: A Landscape Approach to Determining and Predicting Juvenile Coho Salmon (<i>Oncorhynchus kisutch</i>) Movement Timing and Growth Patterns Prior to Ocean Entry Author: Johnson, Amelia Lee Year: 2016 Coho salmon (Oncorhynchus kisutch) rely on unique habitats during the winter season, which may dictate how much individuals may grow and when migration from freshwater rearing habitat to the ocean occurs. Here I analyze movement timing and growth patterns for coho salmon through a field-based study and a literature review. For the field portion, I examined hatchery-stocked juvenile coho salmon across four stream basins in the Russian River watershed, California to determine the relative importance of climate, landscape, and fish size metrics in predicting movement and growth patterns over a winter rearing and spring smolt outmigration time period (December 2014-June 2015). I observed three unique movement strategies: winter parr movement, spring smolt movement, and inter-tributary movement. Movement was predicted in relation to daily temperature and precipitation, followed by in-stream and upslope basin conditions in random forest modeling. Specifically, fish that moved later were associated with basins that contained higher productivity and low-gradient floodplain habitats, while fish that moved earlier came from streams that lacked invertebrate prey and had limited low-gradient rearing habitat. Fish size and timing of movement were the primary predictors of growth, with relatively larger fish in the spring growing faster than fish that were relatively smaller prior to winter. These relationships suggest that hatchery-release fish are still highly influenced by environmental conditions once released, especially in terms of initial seasonal movement, and that watershed conditions should be considered when utilizing hatchery-rearing programs to supplement wild fish populations. In North America, coho salmon populations are distributed from Alaska through California, and may exhibit unique movement and growth patterns in relationship to population-scale vulnerability (Endangered Species Act listing), basin area, and availability and types of rearing habitat. For the second part of my thesis, I conducted a literature review to assess what factors are commonly considered in predicting movement and growth patterns for these fish, as well as the types (season and life stage) and number of movement strategies reported. Eighteen studies were summarized, of which sixteen identified unique movement strategies, ranging from one to four. Despite a wide range of basin areas and latitudes, winter parr and spring smolt movements were commonly observed, with authors primarily relating these behaviors to in-stream habitat and fish size metrics. Additionally, growth was linked positively and primarily with off-channel winter rearing, which may outweigh the importance of fish size in predicting growth when high quality rearing habitats are available during the winter season. Recognizing movement timing diversity and its drivers can help recover threatened coho salmon populations. More widely distributed populations may have unique phenotypic expressions based on localized genetic and environmental interactions, increasing diversity and overall stability across the population, a concept known as the portfolio effect. Understanding fish-habitat relationships can aid recovery efforts by providing a framework of climatic and watershed conditions that support unique behaviors, even in already severely limited populations. Title: A Landscape Approach to Determining and Predicting Juvenile Coho Salmon (<i>Oncorhynchus kisutch</i>) Movement Timing and Growth Patterns Prior to Ocean Entry Author: Johnson, Amelia Lee Year: 2016 Coho salmon (Oncorhynchus kisutch) rely on unique habitats during the winter season, which may dictate how much individuals may grow and when migration from freshwater rearing habitat to the ocean occurs. Here I analyze movement timing and growth patterns for coho salmon through a field-based study and a literature review. For the field portion, I examined hatchery-stocked juvenile coho salmon across four stream basins in the Russian River watershed, California to determine the relative importance of climate, landscape, and fish size metrics in predicting movement and growth patterns over a winter rearing and spring smolt outmigration time period (December 2014-June 2015). I observed three unique movement strategies: winter parr movement, spring smolt movement, and inter-tributary movement. Movement was predicted in relation to daily temperature and precipitation, followed by in-stream and upslope basin conditions in random forest modeling. Specifically, fish that moved later were associated with basins that contained higher productivity and low-gradient floodplain habitats, while fish that moved earlier came from streams that lacked invertebrate prey and had limited low-gradient rearing habitat. Fish size and timing of movement were the primary predictors of growth, with relatively larger fish in the spring growing faster than fish that were relatively smaller prior to winter. These relationships suggest that hatchery-release fish are still highly influenced by environmental conditions once released, especially in terms of initial seasonal movement, and that watershed conditions should be considered when utilizing hatchery-rearing programs to supplement wild fish populations. In North America, coho salmon populations are distributed from Alaska through California, and may exhibit unique movement and growth patterns in relationship to population-scale vulnerability (Endangered Species Act listing), basin area, and availability and types of rearing habitat. For the second part of my thesis, I conducted a literature review to assess what factors are commonly considered in predicting movement and growth patterns for these fish, as well as the types (season and life stage) and number of movement strategies reported. Eighteen studies were summarized, of which sixteen identified unique movement strategies, ranging from one to four. Despite a wide range of basin areas and latitudes, winter parr and spring smolt movements were commonly observed, with authors primarily relating these behaviors to in-stream habitat and fish size metrics. Additionally, growth was linked positively and primarily with off-channel winter rearing, which may outweigh the importance of fish size in predicting growth when high quality rearing habitats are available during the winter season. Recognizing movement timing diversity and its drivers can help recover threatened coho salmon populations. More widely distributed populations may have unique phenotypic expressions based on localized genetic and environmental interactions, increasing diversity and overall stability across the population, a concept known as the portfolio effect. Understanding fish-habitat relationships can aid recovery efforts by providing a framework of climatic and watershed conditions that support unique behaviors, even in already severely limited populations. Close

• 52. [Article] Future Flooding Impacts on Transportation Infrastructure and Traffic Patterns Resulting from Climate Change

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

  Citation × Citation Citation Abstract Copy Title: Future Flooding Impacts on Transportation Infrastructure and Traffic Patterns Resulting from Climate Change Author: Chang, Heejun, Lafrenz, Martin, Jung, Il-Won, Figliozzi, Miguel A., Melgoza, Rolando, Ruelas, David, Platman, Deena, Pederson, Cindy Year: 2011 This study investigated potential impacts of climate change on travel disruption resulting from road closures in two urban watersheds in the Portland metropolitan area. We used ensemble climate change scenarios, a hydrologic model, 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 period 1988-2006, and simulated for determining the probability of floods from 2020-2049. We surveyed stream cross sections at five road crossings for stream channel geometry and determined floodwater surface elevations using the HEC-RAS model. Four of the surveyed bridges and roadways were lower in elevation than the current 100-year floodwater 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. While vehicle miles traveled were 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. Results indicate that any cost analysis is extremely sensitive to the occurrence of human fatalities or injuries and fairly insensitive to delay costs. In addition, this research presents a comprehensive classification of flooding costs, identifies preventative measures, and makes short- and long-term recommendations. 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: Future Flooding Impacts on Transportation Infrastructure and Traffic Patterns Resulting from Climate Change Author: Chang, Heejun, Lafrenz, Martin, Jung, Il-Won, Figliozzi, Miguel A., Melgoza, Rolando, Ruelas, David, Platman, Deena, Pederson, Cindy Year: 2011 This study investigated potential impacts of climate change on travel disruption resulting from road closures in two urban watersheds in the Portland metropolitan area. We used ensemble climate change scenarios, a hydrologic model, 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 period 1988-2006, and simulated for determining the probability of floods from 2020-2049. We surveyed stream cross sections at five road crossings for stream channel geometry and determined floodwater surface elevations using the HEC-RAS model. Four of the surveyed bridges and roadways were lower in elevation than the current 100-year floodwater 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. While vehicle miles traveled were 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. Results indicate that any cost analysis is extremely sensitive to the occurrence of human fatalities or injuries and fairly insensitive to delay costs. In addition, this research presents a comprehensive classification of flooding costs, identifies preventative measures, and makes short- and long-term recommendations. 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

• 53. [Article] Spatial, Temporal and Frequency Based Climate change Assessment in Columbia River Basin Using Multi Downscaled-Scenarios

  Uncertainties in climate modelling are well documented in literature. Global Climate Models (GCMs) are often used to downscale the climatic parameters on a regional scale. In the present work, we have ...

  Citation × Citation Citation Abstract Copy Title: Spatial, Temporal and Frequency Based Climate change Assessment in Columbia River Basin Using Multi Downscaled-Scenarios Author: Rana, Arun, Moradkhani, Hamid Year: 2016 Uncertainties in climate modelling are well documented in literature. Global Climate Models (GCMs) are often used to downscale the climatic parameters on a regional scale. In the present work, we have analyzed the changes in precipitation and temperature for future scenario period of 2070–2099 with respect to historical period of 1970–2000 from statistically downscaled GCM projections in Columbia River Basin (CRB). Analysis is performed using two different statistically downscaled climate projections (with ten GCMs downscaled products each, for RCP 4.5 and RCP 8.5, from CMIP5 dataset) namely, those from the Bias Correction and Spatial Downscaling (BCSD) technique generated at Portland State University and from the Multivariate Adaptive Constructed Analogs (MACA) technique, generated at University of Idaho, totaling to 40 different scenarios. The two datasets for BCSD and MACA are downscaled from observed data for both scenarios projections i.e. RCP4.5 and RCP8.5. Analysis is performed using spatial change (yearly scale), temporal change (monthly scale), percentile change (seasonal scale), quantile change (yearly scale), and wavelet analysis (yearly scale) in the future period from the historical period, respectively, at a scale of 1/16th of degree for entire CRB region. Results have indicated in varied degree of spatial change pattern for the entire Columbia River Basin, especially western part of the basin. At temporal scales, winter precipitation has higher variability than summer and vice versa for temperature. Most of the models have indicated considerate positive change in quantiles and percentiles for both precipitation and temperature. Wavelet analysis provided insights into possible explanation to changes in precipitation. Title: Spatial, Temporal and Frequency Based Climate change Assessment in Columbia River Basin Using Multi Downscaled-Scenarios Author: Rana, Arun, Moradkhani, Hamid Year: 2016 Uncertainties in climate modelling are well documented in literature. Global Climate Models (GCMs) are often used to downscale the climatic parameters on a regional scale. In the present work, we have analyzed the changes in precipitation and temperature for future scenario period of 2070–2099 with respect to historical period of 1970–2000 from statistically downscaled GCM projections in Columbia River Basin (CRB). Analysis is performed using two different statistically downscaled climate projections (with ten GCMs downscaled products each, for RCP 4.5 and RCP 8.5, from CMIP5 dataset) namely, those from the Bias Correction and Spatial Downscaling (BCSD) technique generated at Portland State University and from the Multivariate Adaptive Constructed Analogs (MACA) technique, generated at University of Idaho, totaling to 40 different scenarios. The two datasets for BCSD and MACA are downscaled from observed data for both scenarios projections i.e. RCP4.5 and RCP8.5. Analysis is performed using spatial change (yearly scale), temporal change (monthly scale), percentile change (seasonal scale), quantile change (yearly scale), and wavelet analysis (yearly scale) in the future period from the historical period, respectively, at a scale of 1/16th of degree for entire CRB region. Results have indicated in varied degree of spatial change pattern for the entire Columbia River Basin, especially western part of the basin. At temporal scales, winter precipitation has higher variability than summer and vice versa for temperature. Most of the models have indicated considerate positive change in quantiles and percentiles for both precipitation and temperature. Wavelet analysis provided insights into possible explanation to changes in precipitation. Close

• 54. [Article] Investigating the Link Between Surface Water and Groundwater in the Tule Lake Subbasin, Oregon and California

  Water allocation in the upper Klamath Basin of Oregon and California has been challenging. Irrigators have increasingly turned to groundwater to make up for surface water shortages because of shifts in ...

  Citation × Citation Citation Abstract Copy Title: Investigating the Link Between Surface Water and Groundwater in the Tule Lake Subbasin, Oregon and California Author: Pischel, Esther Maria Year: 2014 Water allocation in the upper Klamath Basin of Oregon and California has been challenging. Irrigators have increasingly turned to groundwater to make up for surface water shortages because of shifts in allocation toward in-stream flows for Endangered Species Act listed fishes. The largest increase in groundwater pumping has been in and around the Bureau of Reclamation's Klamath Irrigation Project, which includes the Tule Lake subbasin in the southern part of the upper Klamath Basin. Previous groundwater flow model simulations indicate that water level declines from pumping may result in decreased flow to agricultural drains in the Tule Lake subbasin. Agricultural drains on the Klamath Project are an important source of water for downstream irrigators and for the Tule Lake and Lower Klamath Lake National Wildlife Refuges. To better assess the impact of increased pumping on drain flow and on the water balance of the groundwater system, flow data from agricultural drains were evaluated to investigate the changes that have taken place in groundwater discharge to drains since pumping volumes increased. Additionally, a fine-grid groundwater model of the Tule Lake subbasin was developed based on the existing regional flow model. The fine-grid model has sufficient vertical and horizontal resolution to simulate vertical head gradients, takes advantage of time-series data from 38 observation wells for model calibration, and allows agricultural drains to be more explicitly represented. Results of the drain flow analysis show that the groundwater discharge to agricultural drains has decreased by approximately 4000 hectare-meters from the 1997-2000 average discharge. Most of this decrease takes place in the northern and southeastern portions of the subbasin. Results of the groundwater model show that the initial source of water to wells is groundwater storage. By 2006, approximately 56% of the water from wells is sourced from agricultural drains. Title: Investigating the Link Between Surface Water and Groundwater in the Tule Lake Subbasin, Oregon and California Author: Pischel, Esther Maria Year: 2014 Water allocation in the upper Klamath Basin of Oregon and California has been challenging. Irrigators have increasingly turned to groundwater to make up for surface water shortages because of shifts in allocation toward in-stream flows for Endangered Species Act listed fishes. The largest increase in groundwater pumping has been in and around the Bureau of Reclamation's Klamath Irrigation Project, which includes the Tule Lake subbasin in the southern part of the upper Klamath Basin. Previous groundwater flow model simulations indicate that water level declines from pumping may result in decreased flow to agricultural drains in the Tule Lake subbasin. Agricultural drains on the Klamath Project are an important source of water for downstream irrigators and for the Tule Lake and Lower Klamath Lake National Wildlife Refuges. To better assess the impact of increased pumping on drain flow and on the water balance of the groundwater system, flow data from agricultural drains were evaluated to investigate the changes that have taken place in groundwater discharge to drains since pumping volumes increased. Additionally, a fine-grid groundwater model of the Tule Lake subbasin was developed based on the existing regional flow model. The fine-grid model has sufficient vertical and horizontal resolution to simulate vertical head gradients, takes advantage of time-series data from 38 observation wells for model calibration, and allows agricultural drains to be more explicitly represented. Results of the drain flow analysis show that the groundwater discharge to agricultural drains has decreased by approximately 4000 hectare-meters from the 1997-2000 average discharge. Most of this decrease takes place in the northern and southeastern portions of the subbasin. Results of the groundwater model show that the initial source of water to wells is groundwater storage. By 2006, approximately 56% of the water from wells is sourced from agricultural drains. Close

• 55. [Article] A Performance Assessment of Two Multi-component Water Quality Facilities in the Columbia Slough and Fairview Creek Watersheds

  We examined the treatment trains at the Columbia Slough (CSWQF) and Fairview Creek Water Quality Facilities (FCWQF) in Gresham, OR and assessed their effectiveness at removing pollutants including nutrients, ...

  Citation × Citation Citation Abstract Copy Title: A Performance Assessment of Two Multi-component Water Quality Facilities in the Columbia Slough and Fairview Creek Watersheds Author: Robinson, Christopher Year: 2012 We examined the treatment trains at the Columbia Slough (CSWQF) and Fairview Creek Water Quality Facilities (FCWQF) in Gresham, OR and assessed their effectiveness at removing pollutants including nutrients, TSS, metals, pesticides, PAHs, and VOCs. Time-paced, fixed volume composite samples were collected during storm events at the inlets and outlet of the CSWQF and at the inlets and outlet of each treatment train component of the FCWQF. In addition, long-term data collected at the FCWQF was analyzed. Composite data collected during November 2-3, 2011 and March 5-6, 2012 showed that the treatment trains can measurably reduce the event mean concentration (EMC) of most pollutants present in stormwater. Removal efficiencies ranged from a low of 11 to 34 percent for nutrients to a high of 58 to 70 percent for TSS. Long-term data from the FCWQF confirms the findings of the individual sampling events and demonstrates that the FCWQF treatment train significantly reduces the EMCs of NH3-N, TKN, BOD5, most of the heavy metals tested for, bacteria, TSS, and turbidity. When compared to data available from the International Stormwater BMP Database, effluent concentrations at the FCWQF were comparable to or lower than those in the BMP Database for nutrients including TKN, OP, and TP; metals including DCu, TCu, TNi, DPb, and TPb; and TSS. Effluent concentrations at the FCWQF were higher than those in the BMP Database for DZn, TZn, turbidity, and bacteria. When comparing the two facilities, the FCWQF generally reduced pollutant concentrations to a greater degree than did the CSWQF. Pollutant removal efficiency was potentially limited by rainfall intensity and seasonal factors, with removal efficiencies being higher for the spring event than the fall event. It is recommended that long-term monitoring be continued at both facilities until the pollutant removal efficiency of the entire CSWQF and the FCWQF treatment train components can be statistically quantified. Changes in sample collection methods and flow measurement are recommended that could improve the accuracy of pollutant concentration estimates considerably. Finally, it is recommended that further research be conducted to determine if significant relationships can be established between particle size and the following pollutants: heavy metals, total phosphorus, and PAHs. Defining these relationships may make it possible to estimate pollutant concentrations using the stormwater particle size distribution analysis. Title: A Performance Assessment of Two Multi-component Water Quality Facilities in the Columbia Slough and Fairview Creek Watersheds Author: Robinson, Christopher Year: 2012 We examined the treatment trains at the Columbia Slough (CSWQF) and Fairview Creek Water Quality Facilities (FCWQF) in Gresham, OR and assessed their effectiveness at removing pollutants including nutrients, TSS, metals, pesticides, PAHs, and VOCs. Time-paced, fixed volume composite samples were collected during storm events at the inlets and outlet of the CSWQF and at the inlets and outlet of each treatment train component of the FCWQF. In addition, long-term data collected at the FCWQF was analyzed. Composite data collected during November 2-3, 2011 and March 5-6, 2012 showed that the treatment trains can measurably reduce the event mean concentration (EMC) of most pollutants present in stormwater. Removal efficiencies ranged from a low of 11 to 34 percent for nutrients to a high of 58 to 70 percent for TSS. Long-term data from the FCWQF confirms the findings of the individual sampling events and demonstrates that the FCWQF treatment train significantly reduces the EMCs of NH3-N, TKN, BOD5, most of the heavy metals tested for, bacteria, TSS, and turbidity. When compared to data available from the International Stormwater BMP Database, effluent concentrations at the FCWQF were comparable to or lower than those in the BMP Database for nutrients including TKN, OP, and TP; metals including DCu, TCu, TNi, DPb, and TPb; and TSS. Effluent concentrations at the FCWQF were higher than those in the BMP Database for DZn, TZn, turbidity, and bacteria. When comparing the two facilities, the FCWQF generally reduced pollutant concentrations to a greater degree than did the CSWQF. Pollutant removal efficiency was potentially limited by rainfall intensity and seasonal factors, with removal efficiencies being higher for the spring event than the fall event. It is recommended that long-term monitoring be continued at both facilities until the pollutant removal efficiency of the entire CSWQF and the FCWQF treatment train components can be statistically quantified. Changes in sample collection methods and flow measurement are recommended that could improve the accuracy of pollutant concentration estimates considerably. Finally, it is recommended that further research be conducted to determine if significant relationships can be established between particle size and the following pollutants: heavy metals, total phosphorus, and PAHs. Defining these relationships may make it possible to estimate pollutant concentrations using the stormwater particle size distribution analysis. Close

• 56. [Article] Report on Nutria Management and Research in the Pacific Northwest

  The nutria (Myocastor coypus) is a large semi-aquatic mammal native to South America that has been introduced to numerous countries around the world, primarily for fur farming. Nutria were introduced in ...

  Citation × Citation Citation Abstract Copy Title: Report on Nutria Management and Research in the Pacific Northwest Author: Sheffels, Trevor Robert, Sytsma, Mark Year: 2007 The nutria (Myocastor coypus) is a large semi-aquatic mammal native to South America that has been introduced to numerous countries around the world, primarily for fur farming. Nutria were introduced in Oregon and Washington in the 1930s, and feral populations were documented in 1943. Populations are known to be expanding in both Oregon and Washington, and regional nutria damage and nuisance complaints have increased in recent years. Most of the extensive damage caused by nutria is a direct result of feeding and burrowing, but nutria are also capable of transporting parasites and pathogens transmittable to humans, livestock, and pets. Although several past regional and local nutria research and management projects have been identified, there is a shortage of nutria information from the Pacific Northwest considering that the species has been present in the region for approximately seventy years. The Center for Lakes and Reservoirs (CLR) at Portland State University (PSU), in partnership with several local, state, and federal agencies, has taken the lead in addressing the regional nutria problem. Activities completed to date include a regional nutria management workshop, the ongoing development of a regional nutria distribution/density map, and a research project to analyze the impact of nutria herbivory on regional riparian wetland habitat restoration projects. In addition, the CLR at PSU is participating in the development of the national Aquatic Nuisance Species Task Force nutria management plan. This initial assessment of the current nutria situation in the Pacific Northwest conducted by the CLR at PSU has revealed that regional nutria problems are more extensive than previously realized. Nutria sightings have now been confirmed from the Canadian border to near the southern border of Oregon, confirming a larger range than was previously known. It was also found that the main nutria issues in the Pacific Northwest differ from the main nutria issues in Louisiana and Maryland. For example, the most significant category of regional nutria damage appears to be the destruction of water control structures and associated erosion caused by nutria burrowing, as opposed to nutria herbivory damage in Louisiana and Maryland. Another unique situation in the Pacific Northwest is the high density of nutria populations in urban areas, increasing the potential for conflicts between nutria and humans. Nutria attacks have been reported in isolated cases, and nutria are rodents that carry a variety of transmittable parasites and pathogens. It has also been confirmed that significant regional nutria herbivory damage does occur at some locations. Fortunately, it has become evident through the course of this assessment that a strong regional interest to address the nutria problem exists. A wide variety of agencies and organizations across the region are being negatively impacted by nutria, and these entities are ready to move forward to develop a feasible solution. To date, small-scale nutria management and eradication efforts have been somewhat effective temporarily, but a more permanent solution requires that the situation be addressed on a much larger scale. Due to the long period of time since the initial nutria introduction, the extent of current regional nutria populations, and the changing climate patterns, a long-term effort will likely be required to effectively address the regional nutria issue. The most immediate management need is to develop an official regional nutria management plan with the focus of greatly reducing the amount of damage being caused by this invasive rodent and preventing further population growth and expansion. The effectiveness of initial management efforts will shed light on how to adapt management strategies in the future and whether or not regional eradication is a feasible option. Continued nutria research and the development of coordinated management efforts at the regional scale are vital in order to bring the current regional nutria problem under control. The CLR at PSU has developed initial recommendations to help guide the process of determining how to most effectively manage nutria in the Pacific Northwest. First and foremost, funding sources for continued work on the regional nutria problem must be found. Once funding is secured, the development of an official nutria regional management plan is crucial. Priorities connected with the management plan would include creating an early detection rapid response plan, identifying best management practices, initiating a pilot eradication program, and identifying priority research needs. Potential research studies include a long-term pilot eradication project at the watershed level, relationships between climate change and regional nutria dispersal, and the dynamics of nutria-muskrat interactions. It is also evident that further coordination between local, state, and federal agencies is necessary to delegate responsibilities and keep all parties updated. The creation of a central regional database and appropriate agency protocols could be used to collect information about nutria damage and associated economic impacts. Current laws and regulations pertaining to nutria should be enforced and possibly updated so that Oregon and Washington laws are uniform. Finally, it is important to inform the public about current nutria issues and utilize resources the general public can potentially provide. Title: Report on Nutria Management and Research in the Pacific Northwest Author: Sheffels, Trevor Robert, Sytsma, Mark Year: 2007 The nutria (Myocastor coypus) is a large semi-aquatic mammal native to South America that has been introduced to numerous countries around the world, primarily for fur farming. Nutria were introduced in Oregon and Washington in the 1930s, and feral populations were documented in 1943. Populations are known to be expanding in both Oregon and Washington, and regional nutria damage and nuisance complaints have increased in recent years. Most of the extensive damage caused by nutria is a direct result of feeding and burrowing, but nutria are also capable of transporting parasites and pathogens transmittable to humans, livestock, and pets. Although several past regional and local nutria research and management projects have been identified, there is a shortage of nutria information from the Pacific Northwest considering that the species has been present in the region for approximately seventy years. The Center for Lakes and Reservoirs (CLR) at Portland State University (PSU), in partnership with several local, state, and federal agencies, has taken the lead in addressing the regional nutria problem. Activities completed to date include a regional nutria management workshop, the ongoing development of a regional nutria distribution/density map, and a research project to analyze the impact of nutria herbivory on regional riparian wetland habitat restoration projects. In addition, the CLR at PSU is participating in the development of the national Aquatic Nuisance Species Task Force nutria management plan. This initial assessment of the current nutria situation in the Pacific Northwest conducted by the CLR at PSU has revealed that regional nutria problems are more extensive than previously realized. Nutria sightings have now been confirmed from the Canadian border to near the southern border of Oregon, confirming a larger range than was previously known. It was also found that the main nutria issues in the Pacific Northwest differ from the main nutria issues in Louisiana and Maryland. For example, the most significant category of regional nutria damage appears to be the destruction of water control structures and associated erosion caused by nutria burrowing, as opposed to nutria herbivory damage in Louisiana and Maryland. Another unique situation in the Pacific Northwest is the high density of nutria populations in urban areas, increasing the potential for conflicts between nutria and humans. Nutria attacks have been reported in isolated cases, and nutria are rodents that carry a variety of transmittable parasites and pathogens. It has also been confirmed that significant regional nutria herbivory damage does occur at some locations. Fortunately, it has become evident through the course of this assessment that a strong regional interest to address the nutria problem exists. A wide variety of agencies and organizations across the region are being negatively impacted by nutria, and these entities are ready to move forward to develop a feasible solution. To date, small-scale nutria management and eradication efforts have been somewhat effective temporarily, but a more permanent solution requires that the situation be addressed on a much larger scale. Due to the long period of time since the initial nutria introduction, the extent of current regional nutria populations, and the changing climate patterns, a long-term effort will likely be required to effectively address the regional nutria issue. The most immediate management need is to develop an official regional nutria management plan with the focus of greatly reducing the amount of damage being caused by this invasive rodent and preventing further population growth and expansion. The effectiveness of initial management efforts will shed light on how to adapt management strategies in the future and whether or not regional eradication is a feasible option. Continued nutria research and the development of coordinated management efforts at the regional scale are vital in order to bring the current regional nutria problem under control. The CLR at PSU has developed initial recommendations to help guide the process of determining how to most effectively manage nutria in the Pacific Northwest. First and foremost, funding sources for continued work on the regional nutria problem must be found. Once funding is secured, the development of an official nutria regional management plan is crucial. Priorities connected with the management plan would include creating an early detection rapid response plan, identifying best management practices, initiating a pilot eradication program, and identifying priority research needs. Potential research studies include a long-term pilot eradication project at the watershed level, relationships between climate change and regional nutria dispersal, and the dynamics of nutria-muskrat interactions. It is also evident that further coordination between local, state, and federal agencies is necessary to delegate responsibilities and keep all parties updated. The creation of a central regional database and appropriate agency protocols could be used to collect information about nutria damage and associated economic impacts. Current laws and regulations pertaining to nutria should be enforced and possibly updated so that Oregon and Washington laws are uniform. Finally, it is important to inform the public about current nutria issues and utilize resources the general public can potentially provide. Close

• 57. [Article] Effects of HRU Size on PRMS Performance in 30 Western U.S. Basins

  Semi-distributed hydrological models are often used for streamflow forecasting, hydrological climate change impact assessments, and other applications. In such models, basins are broken up into hydrologic ...

  Citation × Citation Citation Abstract Copy Title: Effects of HRU Size on PRMS Performance in 30 Western U.S. Basins Author: Steele, Madeline Olena Year: 2013 Semi-distributed hydrological models are often used for streamflow forecasting, hydrological climate change impact assessments, and other applications. In such models, basins are broken up into hydrologic response units (HRUs), which are assumed to have a relatively homogenous response to precipitation. HRUs are delineated in a variety of ways, and the procedure used may impact model performance. HRU delineation procedures have been researched, but it is still not clear how important these subdivision schemes are or which delineation methods are most effective. To start addressing this knowledge gap, this project investigated whether or not HRU size has a significant effect on streamflow simulation at the mouth of a watershed. To test this, 30 gaged, relatively unimpaired western U.S. basins were each modeled with 6 HRU sets of different sizes using the Precipitation Runoff Modeling System (PRMS). To isolate size as a variable, HRUs were delineated using stream catchments. For each basin, streams were defined with 6 different threshold levels, producing HRUs of differing sizes. Nineteen model parameters were derived for each HRU using nationally consistent GIS datasets, and all other model parameters were left at default values. Climate inputs were derived from a national 4-km2 gridded daily climate dataset. After calibration, 4 goodness-of-fit metrics were calculated for daily streamflow for each HRU set. Uncalibrated model performance was generally poor for a variety of reasons, but comparison of the models was still informative. Results for the 30 basins across the 6 HRU size classes showed that HRU size did not significantly impact model performance across all basins. However, in basins that had less total precipitation and higher elevation, sensitivity of model performance to HRU subdivision levels was slightly greater, though not significantly so. Findings indicate that, in most basins, little subdivision may be required for good model performance, allowing for desirable simplicity and fewer degrees of freedom without sacrificing runoff simulation accuracy. Title: Effects of HRU Size on PRMS Performance in 30 Western U.S. Basins Author: Steele, Madeline Olena Year: 2013 Semi-distributed hydrological models are often used for streamflow forecasting, hydrological climate change impact assessments, and other applications. In such models, basins are broken up into hydrologic response units (HRUs), which are assumed to have a relatively homogenous response to precipitation. HRUs are delineated in a variety of ways, and the procedure used may impact model performance. HRU delineation procedures have been researched, but it is still not clear how important these subdivision schemes are or which delineation methods are most effective. To start addressing this knowledge gap, this project investigated whether or not HRU size has a significant effect on streamflow simulation at the mouth of a watershed. To test this, 30 gaged, relatively unimpaired western U.S. basins were each modeled with 6 HRU sets of different sizes using the Precipitation Runoff Modeling System (PRMS). To isolate size as a variable, HRUs were delineated using stream catchments. For each basin, streams were defined with 6 different threshold levels, producing HRUs of differing sizes. Nineteen model parameters were derived for each HRU using nationally consistent GIS datasets, and all other model parameters were left at default values. Climate inputs were derived from a national 4-km2 gridded daily climate dataset. After calibration, 4 goodness-of-fit metrics were calculated for daily streamflow for each HRU set. Uncalibrated model performance was generally poor for a variety of reasons, but comparison of the models was still informative. Results for the 30 basins across the 6 HRU size classes showed that HRU size did not significantly impact model performance across all basins. However, in basins that had less total precipitation and higher elevation, sensitivity of model performance to HRU subdivision levels was slightly greater, though not significantly so. Findings indicate that, in most basins, little subdivision may be required for good model performance, allowing for desirable simplicity and fewer degrees of freedom without sacrificing runoff simulation accuracy. Close

• 58. [Article] Towards Improving Drought Forecasts Across Different Spatial and Temporal Scales

  Recent water scarcities across the southwestern U.S. with severe effects on the living environment inspire the development of new methodologies to achieve reliable drought forecasting in seasonal scale. ...

  Citation × Citation Citation Abstract Copy Title: Towards Improving Drought Forecasts Across Different Spatial and Temporal Scales Author: Madadgar, Shahrbanou Year: 2014 Recent water scarcities across the southwestern U.S. with severe effects on the living environment inspire the development of new methodologies to achieve reliable drought forecasting in seasonal scale. Reliable forecast of hydrologic variables, in general, is a preliminary requirement for appropriate planning of water resources and developing effective allocation policies. This study aims at developing new techniques with specific probabilistic features to improve the reliability of hydrologic forecasts, particularly the drought forecasts. The drought status in the future is determined by certain hydrologic variables that are basically estimated by the hydrologic models with rather simple to complex structures. Since the predictions of hydrologic models are prone to different sources of uncertainties, there have been several techniques examined during past several years which generally attempt to combine the predictions of single (multiple) hydrologic models to generate an ensemble of hydrologic forecasts addressing the inherent uncertainties. However, the imperfect structure of hydrologic models usually lead to systematic bias of hydrologic predictions that further appears in the forecast ensembles. This study proposes a post-processing method that is applied to the raw forecast of hydrologic variables and can develop the entire distribution of forecast around the initial single-value prediction. To establish the probability density function (PDF) of the forecast, a group of multivariate distribution functions, the so-called copula functions, are incorporated in the post-processing procedure. The performance of the new post-processing technique is tested on 2500 hypothetical case studies and the streamflow forecast of Sprague River Basin in southern Oregon. Verified by some deterministic and probabilistic verification measures, the method of Quantile Mapping as a traditional post-processing technique cannot generate the qualified forecasts as comparing with the copula-based method. The post-processing technique is then expanded to exclusively study the drought forecasts across the different spatial and temporal scales. In the proposed drought forecasting model, the drought status in the future is evaluated based on the drought status of the past seasons while the correlations between the drought variables of consecutive seasons are preserved by copula functions. The main benefit of the new forecast model is its probabilistic features in analyzing future droughts. It develops conditional probability of drought status in the forecast season and generates the PDF and cumulative distribution function (CDF) of future droughts given the past status. The conditional PDF can return the highest probable drought in the future along with an assessment of the uncertainty around that value. Using the conditional CDF for forecast season, the model can generate the maps of drought status across the basin with particular chance of occurrence in the future. In a different analysis of the conditional CDF developed for the forecast season, the chance of a particular drought in the forecast period can be approximated given the drought status of earlier seasons. The forecast methodology developed in this study shows promising results in hydrologic forecasts and its particular probabilistic features are inspiring for future studies. Title: Towards Improving Drought Forecasts Across Different Spatial and Temporal Scales Author: Madadgar, Shahrbanou Year: 2014 Recent water scarcities across the southwestern U.S. with severe effects on the living environment inspire the development of new methodologies to achieve reliable drought forecasting in seasonal scale. Reliable forecast of hydrologic variables, in general, is a preliminary requirement for appropriate planning of water resources and developing effective allocation policies. This study aims at developing new techniques with specific probabilistic features to improve the reliability of hydrologic forecasts, particularly the drought forecasts. The drought status in the future is determined by certain hydrologic variables that are basically estimated by the hydrologic models with rather simple to complex structures. Since the predictions of hydrologic models are prone to different sources of uncertainties, there have been several techniques examined during past several years which generally attempt to combine the predictions of single (multiple) hydrologic models to generate an ensemble of hydrologic forecasts addressing the inherent uncertainties. However, the imperfect structure of hydrologic models usually lead to systematic bias of hydrologic predictions that further appears in the forecast ensembles. This study proposes a post-processing method that is applied to the raw forecast of hydrologic variables and can develop the entire distribution of forecast around the initial single-value prediction. To establish the probability density function (PDF) of the forecast, a group of multivariate distribution functions, the so-called copula functions, are incorporated in the post-processing procedure. The performance of the new post-processing technique is tested on 2500 hypothetical case studies and the streamflow forecast of Sprague River Basin in southern Oregon. Verified by some deterministic and probabilistic verification measures, the method of Quantile Mapping as a traditional post-processing technique cannot generate the qualified forecasts as comparing with the copula-based method. The post-processing technique is then expanded to exclusively study the drought forecasts across the different spatial and temporal scales. In the proposed drought forecasting model, the drought status in the future is evaluated based on the drought status of the past seasons while the correlations between the drought variables of consecutive seasons are preserved by copula functions. The main benefit of the new forecast model is its probabilistic features in analyzing future droughts. It develops conditional probability of drought status in the forecast season and generates the PDF and cumulative distribution function (CDF) of future droughts given the past status. The conditional PDF can return the highest probable drought in the future along with an assessment of the uncertainty around that value. Using the conditional CDF for forecast season, the model can generate the maps of drought status across the basin with particular chance of occurrence in the future. In a different analysis of the conditional CDF developed for the forecast season, the chance of a particular drought in the forecast period can be approximated given the drought status of earlier seasons. The forecast methodology developed in this study shows promising results in hydrologic forecasts and its particular probabilistic features are inspiring for future studies. Close