Search

Search Results

• 1. [Article] Impacts of Climate Change and Urban Development on Water Resources in the Tualatin River Basin

  Potential impacts of climate change on the water resources of the Pacific Northwest of the United States include earlier peak runoff, reduced summer flows, and increased winter flooding. An increase in ...

  Citation × Citation Citation Abstract Copy Title: Impacts of Climate Change and Urban Development on Water Resources in the Tualatin River Basin Author: Praskievicz, Sarah Year: 2009 Potential impacts of climate change on the water resources of the Pacific Northwest of the United States include earlier peak runoff, reduced summer flows, and increased winter flooding. An increase in impervious surfaces, accompanied by urban development, is known to decrease infiltration and increase surface runoff. Alterations of flow amount and pathways can alter water quality through dilution or flushing effects. I used the United States Environmental Protection Agency's Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) modeling system to investigate the relative importance of future climate change and land use change in determining the quantity and quality of freshwater resources in north western Oregon's Tualatin River Basin. The basin was chosen for this study because it is rapidly urbanizing and representative of other low-elevation basins in the region. BASINS models were calibrated and validated using historic flow and water quality data from 1991 to 2006. The goodness-of-fit for the calibrated hydrology, suspended sediment, and orthophosphate models was high, with coefficients of determination ranging from 0.72 to 0.93 in the calibration period. The calibrated models were run under a range of eight downscaled climate change, two regional land use change, and four combined scenarios. Results included average increases in winter flows of ten percent, decreases in summer flows of thirty-seven percent, and increases in fifth percentile flows of up to eighty percent as a result of climate change in the Tualatin River Basin. For land use change, the results included an increase in annual flows of twenty-one percent for the development-oriented scenario and a decrease of sixteen percent for the conservation-oriented scenario, with amplified changes at the sub-basin scale, including more than doubled winter flow. For combined scenarios of climate change and urban development, there is a projected increase in winter flows of up to seventy-one percent and decrease in summer flows of up to forty-eight percent. Changes in suspended sediment and orthophosphate loading broadly tracked hydrological changes, with winter increases and summer decreases. The results are relevant to regional planners interested in the long-term response of water resources to climate change and land use change at the basin scale. Title: Impacts of Climate Change and Urban Development on Water Resources in the Tualatin River Basin Author: Praskievicz, Sarah Year: 2009 Potential impacts of climate change on the water resources of the Pacific Northwest of the United States include earlier peak runoff, reduced summer flows, and increased winter flooding. An increase in impervious surfaces, accompanied by urban development, is known to decrease infiltration and increase surface runoff. Alterations of flow amount and pathways can alter water quality through dilution or flushing effects. I used the United States Environmental Protection Agency's Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) modeling system to investigate the relative importance of future climate change and land use change in determining the quantity and quality of freshwater resources in north western Oregon's Tualatin River Basin. The basin was chosen for this study because it is rapidly urbanizing and representative of other low-elevation basins in the region. BASINS models were calibrated and validated using historic flow and water quality data from 1991 to 2006. The goodness-of-fit for the calibrated hydrology, suspended sediment, and orthophosphate models was high, with coefficients of determination ranging from 0.72 to 0.93 in the calibration period. The calibrated models were run under a range of eight downscaled climate change, two regional land use change, and four combined scenarios. Results included average increases in winter flows of ten percent, decreases in summer flows of thirty-seven percent, and increases in fifth percentile flows of up to eighty percent as a result of climate change in the Tualatin River Basin. For land use change, the results included an increase in annual flows of twenty-one percent for the development-oriented scenario and a decrease of sixteen percent for the conservation-oriented scenario, with amplified changes at the sub-basin scale, including more than doubled winter flow. For combined scenarios of climate change and urban development, there is a projected increase in winter flows of up to seventy-one percent and decrease in summer flows of up to forty-eight percent. Changes in suspended sediment and orthophosphate loading broadly tracked hydrological changes, with winter increases and summer decreases. The results are relevant to regional planners interested in the long-term response of water resources to climate change and land use change at the basin scale. Close

• 2. [Article] Stream Temperature Management in the Tualatin Watershed: Is it Improving Salmonid Habitat?

  The purpose of this paper is to examine the literature from scientific and governmental entities that describes the problems with elevated stream temperatures in the Tualatin basin, the actions being taken ...

  Citation × Citation Citation Abstract Copy Title: Stream Temperature Management in the Tualatin Watershed: Is it Improving Salmonid Habitat? Author: Hennings, Raymond Banks Year: 2014 The purpose of this paper is to examine the literature from scientific and governmental entities that describes the problems with elevated stream temperatures in the Tualatin basin, the actions being taken to resolve those problems, and to assess whether these actions are meeting the goal of improving salmonid habitat in the basin. Elevated stream temperatures are considered a pollutant under the US Clean Water Act (Clean Water Act 1972, as amended) because increased stream temperatures can be harmful to native aquatic biota, particularly salmonid fish species that have evolved to use cold water (IMST 2004). Title: Stream Temperature Management in the Tualatin Watershed: Is it Improving Salmonid Habitat? Author: Hennings, Raymond Banks Year: 2014 The purpose of this paper is to examine the literature from scientific and governmental entities that describes the problems with elevated stream temperatures in the Tualatin basin, the actions being taken to resolve those problems, and to assess whether these actions are meeting the goal of improving salmonid habitat in the basin. Elevated stream temperatures are considered a pollutant under the US Clean Water Act (Clean Water Act 1972, as amended) because increased stream temperatures can be harmful to native aquatic biota, particularly salmonid fish species that have evolved to use cold water (IMST 2004). Close

• 3. [Article] Oxygen Demand Trends, Land Cover Change, and Water Quality Management for an Urbanizing Oregon Watershed

  In-stream aquatic habitat depends on adequate levels of dissolved oxygen. Human alteration of the landscape has an extensive influence on the biogeochemical processes that drive oxygen cycling in streams. ...

  Citation × Citation Citation Abstract Copy Title: Oxygen Demand Trends, Land Cover Change, and Water Quality Management for an Urbanizing Oregon Watershed Author: Boeder, Michael Karl Year: 2006 In-stream aquatic habitat depends on adequate levels of dissolved oxygen. Human alteration of the landscape has an extensive influence on the biogeochemical processes that drive oxygen cycling in streams. Historic datasets allow researchers to track trends in chemical parameters concomitant with urbanization, while land cover change analysis allows researchers to identify linkages between water quality trends and landscape change. Using the Seasonal Kendall's test, I examined water quality trends in oxygen demand variables during the mid-1990s to 2003, for twelve sites in the Rock Creek sub-watershed of the Tualatin River, northwest Oregon. Significant trends occurred in each parameter. Dissolved oxygen (DO (%sat)) increased at five sites. Chemical oxygen demand (COD) decreased at seven sites. Total Kjeldahl nitrogen (TKN) decreased at five sites and increased at one site. Ammonium (NH3-N) decreased at one site and increased at one site. Multiple linear regression indicates that nitrogenous oxygen demand accounts for a significant amount of variance in COD at ten of the twelve sites (adjusted R2values from 0.14 to 0.73). Aerial photo interpretation revealed significant land cover change in agricultural land cover (-8% for the entire basin area) and residential land cover (+10% for the entire basin area). Correlation results between seasonal oxygen demand data and land cover values at multiple scales indicated that: (I) forest cover negatively influences COD at the full sub-basin scale and positively influences NH3-N at local scales, (2) residential land cover positively influences DO (%sat) values at local scales, (3) agricultural land cover does not influence oxygen demand at any land cover assessment scale, ( 4) local topography negatively influences TKN and NH3-N, and (5) urban runoff management infrastructure correlates positively with COD. Study results indicate that, with the exception of forested land, local scale land cover and landscape variables dominate influence on oxygen demand in the Rock Creek basin. Since DO conditions have improved in these streams, watershed management efforts should emphasize local influences in order to continue to maintain stream health. Title: Oxygen Demand Trends, Land Cover Change, and Water Quality Management for an Urbanizing Oregon Watershed Author: Boeder, Michael Karl Year: 2006 In-stream aquatic habitat depends on adequate levels of dissolved oxygen. Human alteration of the landscape has an extensive influence on the biogeochemical processes that drive oxygen cycling in streams. Historic datasets allow researchers to track trends in chemical parameters concomitant with urbanization, while land cover change analysis allows researchers to identify linkages between water quality trends and landscape change. Using the Seasonal Kendall's test, I examined water quality trends in oxygen demand variables during the mid-1990s to 2003, for twelve sites in the Rock Creek sub-watershed of the Tualatin River, northwest Oregon. Significant trends occurred in each parameter. Dissolved oxygen (DO (%sat)) increased at five sites. Chemical oxygen demand (COD) decreased at seven sites. Total Kjeldahl nitrogen (TKN) decreased at five sites and increased at one site. Ammonium (NH3-N) decreased at one site and increased at one site. Multiple linear regression indicates that nitrogenous oxygen demand accounts for a significant amount of variance in COD at ten of the twelve sites (adjusted R2values from 0.14 to 0.73). Aerial photo interpretation revealed significant land cover change in agricultural land cover (-8% for the entire basin area) and residential land cover (+10% for the entire basin area). Correlation results between seasonal oxygen demand data and land cover values at multiple scales indicated that: (I) forest cover negatively influences COD at the full sub-basin scale and positively influences NH3-N at local scales, (2) residential land cover positively influences DO (%sat) values at local scales, (3) agricultural land cover does not influence oxygen demand at any land cover assessment scale, ( 4) local topography negatively influences TKN and NH3-N, and (5) urban runoff management infrastructure correlates positively with COD. Study results indicate that, with the exception of forested land, local scale land cover and landscape variables dominate influence on oxygen demand in the Rock Creek basin. Since DO conditions have improved in these streams, watershed management efforts should emphasize local influences in order to continue to maintain stream health. Close

• 4. [Article] The Nisqually Watershed From the Summit to the Sound: A Field Guide

  Occasional Papers in Geography Publication No. 6 This guide begins at the summit of Mount Rainier and, like a drop of water, descends toward the sea. It provides information about geological, hydrological, ...

  Citation × Citation Citation Abstract Copy Title: The Nisqually Watershed From the Summit to the Sound: A Field Guide Author: Hixson, Rebecca D., Bulman, Teresa L. Year: 2002 Occasional Papers in Geography Publication No. 6 This guide begins at the summit of Mount Rainier and, like a drop of water, descends toward the sea. It provides information about geological, hydrological, geographical, biological and historical aspects of the Nisqually watershed. It describes the natural resources in the area and identifies how the use of those resources affects water resources and quantity. In the course of this trip, you will be able to follow the Nisqually River along its journey from the summit of Mount Rainier to the Puget Sound and learn about the changes that have occurred within this 720-square-mile-watershed over the past 200 years, the problems that have arisen and the efforts that are being taken to protect this valuable and scenic area. Title: The Nisqually Watershed From the Summit to the Sound: A Field Guide Author: Hixson, Rebecca D., Bulman, Teresa L. Year: 2002 Occasional Papers in Geography Publication No. 6 This guide begins at the summit of Mount Rainier and, like a drop of water, descends toward the sea. It provides information about geological, hydrological, geographical, biological and historical aspects of the Nisqually watershed. It describes the natural resources in the area and identifies how the use of those resources affects water resources and quantity. In the course of this trip, you will be able to follow the Nisqually River along its journey from the summit of Mount Rainier to the Puget Sound and learn about the changes that have occurred within this 720-square-mile-watershed over the past 200 years, the problems that have arisen and the efforts that are being taken to protect this valuable and scenic area. Close

• 5. [Article] An Assessment of the Impacts of Climate Change on the Upper Clackamas River Basin with a Distributed Hydrologic Model

  The Pacific Northwest is dependent on seasonal snowmelt for water resources that support a significant portion of its economy. Increased temperatures resulting from higher concentrations of atmospheric ...

  Citation × Citation Citation Abstract Copy Title: An Assessment of the Impacts of Climate Change on the Upper Clackamas River Basin with a Distributed Hydrologic Model Author: Graves, David Year: 2005 The Pacific Northwest is dependent on seasonal snowmelt for water resources that support a significant portion of its economy. Increased temperatures resulting from higher concentrations of atmospheric greenhouse gases may cause disruptions to these resources because of reductions in the annual snowpack and variations of the timing of snowmelt. This study reconstructs and applies a GIS-based distributed hydrologic model at a monthly scale to assess the effects of future climate change on runoff from the Upper Clackamas River Basin (located near Portland, Oregon). Historic flow data and snow measurements are used to calibrate and test the perfonnance of the hydro logic model for a contemporary period (1971-2000), and the model is run for two future scenarios (2010-2039 and 2070-2099) using IS92 climate change scenarios from two global climate circulation models (Hadley and Canadian Centre for Climate) as inputs. The results forecast that mean peak snowpack in the study area will drop dramatically (36% to 49% by 2010-2039, and 83% to 88% by 2070-2099), resulting in earlier runoff and diminished spring and summer flows. Increases to mean winter runoff by by the 2070-2099 period vary from moderate (13.7%) to large (46.4%), depending on the changes to precipitation forecasted by the global climate circulation models. These results are similar to those of other studies in areas dependent on snowpack for seasonal runoff, but the reductions to snowpack are more severe in this study than similar studies for the entire Columbia Basin, presumably because the elevations of much of the Upper Clackamas Basin are near the current mid-winter snow line. Title: An Assessment of the Impacts of Climate Change on the Upper Clackamas River Basin with a Distributed Hydrologic Model Author: Graves, David Year: 2005 The Pacific Northwest is dependent on seasonal snowmelt for water resources that support a significant portion of its economy. Increased temperatures resulting from higher concentrations of atmospheric greenhouse gases may cause disruptions to these resources because of reductions in the annual snowpack and variations of the timing of snowmelt. This study reconstructs and applies a GIS-based distributed hydrologic model at a monthly scale to assess the effects of future climate change on runoff from the Upper Clackamas River Basin (located near Portland, Oregon). Historic flow data and snow measurements are used to calibrate and test the perfonnance of the hydro logic model for a contemporary period (1971-2000), and the model is run for two future scenarios (2010-2039 and 2070-2099) using IS92 climate change scenarios from two global climate circulation models (Hadley and Canadian Centre for Climate) as inputs. The results forecast that mean peak snowpack in the study area will drop dramatically (36% to 49% by 2010-2039, and 83% to 88% by 2070-2099), resulting in earlier runoff and diminished spring and summer flows. Increases to mean winter runoff by by the 2070-2099 period vary from moderate (13.7%) to large (46.4%), depending on the changes to precipitation forecasted by the global climate circulation models. These results are similar to those of other studies in areas dependent on snowpack for seasonal runoff, but the reductions to snowpack are more severe in this study than similar studies for the entire Columbia Basin, presumably because the elevations of much of the Upper Clackamas Basin are near the current mid-winter snow line. Close

• 6. [Article] Science and Practice of Integrated River Basin Management : Lessons from North and Central American UNESCO-HELP Basins

  The Hydrology for the Environment, Life and Policy (HELP) program, a cross-cutting component of the UNESCO International Hydrological Programme (IHP), has as its goal to facilitate dialogue among hydrologists, ...

  Citation × Citation Citation Abstract Copy Title: Science and Practice of Integrated River Basin Management : Lessons from North and Central American UNESCO-HELP Basins Author: Chang, Heejun, Browning-Aiken, Anne Year: 2010 The Hydrology for the Environment, Life and Policy (HELP) program, a cross-cutting component of the UNESCO International Hydrological Programme (IHP), has as its goal to facilitate dialogue among hydrologists, social and economic scientists, water resource managers, water lawyers, policy experts, and river basin stakeholder communities in setting a research agenda driven by local management and policy issues. HELP seeks to improve the benefits to society by applying the principals of integrated water-resources management to complex, interdisciplinary issues within catchments. This Monograph is the culmination of a workshop held in 2010 in which the managers from the six North American basins (San Pedro, Willamette, Upper Washita, Lake Champlain, Iowa-Cedar, Luquillo) and a Central American basin (Panama Canal), see Figure 1, met to exchange ideas and “lessons learned” in various applications of IWRM within the HELP philosophy. Three major themes were examined: 1. Climate change: Creating watershed resilience 2. Use of social learning in IWRM 3. Knowledge and information management for IWRM Each of these themes is explored in detail and enhanced with case studies of IWRM applications from the participating North and Central American HELP basins. Title: Science and Practice of Integrated River Basin Management : Lessons from North and Central American UNESCO-HELP Basins Author: Chang, Heejun, Browning-Aiken, Anne Year: 2010 The Hydrology for the Environment, Life and Policy (HELP) program, a cross-cutting component of the UNESCO International Hydrological Programme (IHP), has as its goal to facilitate dialogue among hydrologists, social and economic scientists, water resource managers, water lawyers, policy experts, and river basin stakeholder communities in setting a research agenda driven by local management and policy issues. HELP seeks to improve the benefits to society by applying the principals of integrated water-resources management to complex, interdisciplinary issues within catchments. This Monograph is the culmination of a workshop held in 2010 in which the managers from the six North American basins (San Pedro, Willamette, Upper Washita, Lake Champlain, Iowa-Cedar, Luquillo) and a Central American basin (Panama Canal), see Figure 1, met to exchange ideas and “lessons learned” in various applications of IWRM within the HELP philosophy. Three major themes were examined: 1. Climate change: Creating watershed resilience 2. Use of social learning in IWRM 3. Knowledge and information management for IWRM Each of these themes is explored in detail and enhanced with case studies of IWRM applications from the participating North and Central American HELP basins. Close

• 7. [Article] Removing Dams, Constructing Science: Coproduction of Undammed Riverscapes by Politics, Finance, Environment, Society and Technology

  Dam removal in the United States has continued to increase in pace and scope, transitioning from a dam-safety engineering practice to an integral component of many large-scale river restoration programmes. ...

  Citation × Citation Citation Abstract Copy Title: Removing Dams, Constructing Science: Coproduction of Undammed Riverscapes by Politics, Finance, Environment, Society and Technology Author: Grabowski, Zbigniew J., Denton, Ashlie, Rozance, Mary Ann, Matsler, Marissa, Kidd, Sarah Year: 2017 Dam removal in the United States has continued to increase in pace and scope, transitioning from a dam-safety engineering practice to an integral component of many large-scale river restoration programmes. At the same time, knowledge around dam removals remains fragmented by disciplinary silos and a lack of knowledge transfer between communities of practice around dam removal and academia. Here we argue that dam removal science, as a study of large restoration-oriented infrastructure interventions, requires the construction of an interdisciplinary framework to integrate knowledge relevant to decision-making on dam removal. Drawing upon infrastructure studies, relational theories of coproduction of knowledge and social life, and advances within restoration ecology and dam removal science, we present a preliminary framework of dams as systems with irreducibly interrelated political, financial, environmental, social, and technological dimensions (PFESTS). With this framework we analyse three dam removals occurring over a similar time period and within the same narrow geographic region (the Mid-Columbia Region in WA and OR, USA) to demonstrate how each PFESTS dimension contributed to the decision to remove the dam, how it affected the process of removing the dam, and how those dimensions continue to operate post removal in each watershed. We conclude with a discussion of a joint research and practice agenda emerging out of the PFESTS framing. Title: Removing Dams, Constructing Science: Coproduction of Undammed Riverscapes by Politics, Finance, Environment, Society and Technology Author: Grabowski, Zbigniew J., Denton, Ashlie, Rozance, Mary Ann, Matsler, Marissa, Kidd, Sarah Year: 2017 Dam removal in the United States has continued to increase in pace and scope, transitioning from a dam-safety engineering practice to an integral component of many large-scale river restoration programmes. At the same time, knowledge around dam removals remains fragmented by disciplinary silos and a lack of knowledge transfer between communities of practice around dam removal and academia. Here we argue that dam removal science, as a study of large restoration-oriented infrastructure interventions, requires the construction of an interdisciplinary framework to integrate knowledge relevant to decision-making on dam removal. Drawing upon infrastructure studies, relational theories of coproduction of knowledge and social life, and advances within restoration ecology and dam removal science, we present a preliminary framework of dams as systems with irreducibly interrelated political, financial, environmental, social, and technological dimensions (PFESTS). With this framework we analyse three dam removals occurring over a similar time period and within the same narrow geographic region (the Mid-Columbia Region in WA and OR, USA) to demonstrate how each PFESTS dimension contributed to the decision to remove the dam, how it affected the process of removing the dam, and how those dimensions continue to operate post removal in each watershed. We conclude with a discussion of a joint research and practice agenda emerging out of the PFESTS framing. Close