Search

Search Results

• 1. [Article] A Land Use Network for the Johnson Creek Watershed

  This document presents a design for a Land Use Network. It is a starting point from which to build a network that connects, educates, and motivates stakeholders within the Johnson Creek Watershed to facilitate ...

  Citation × Citation Citation Abstract Copy Title: A Land Use Network for the Johnson Creek Watershed Author: Caldwell, Jessica, Felton, Joyce, Redden, Elisa, Pagenstecher, Gerhard Year: 1998 This document presents a design for a Land Use Network. It is a starting point from which to build a network that connects, educates, and motivates stakeholders within the Johnson Creek Watershed to facilitate effective participation in the land use process. The Johnson Creek Watershed Council contracted the Watershed Network Group (WNG) to design the Network as a mechanism for organizing efforts to promote environmentally sound development throughout the watershed. The Johnson Creek Watershed Council comprises representatives from government, residents, and business organizations with interest in the Johnson Creek Watershed. The need for a Land Use Network within the watershed arose because existing methods of monitoring and managing the effects of development on the watershed are inadequate for meeting current development pressures. Development pressures on the watershed have had negative effects on the watershed environment. Development pressures are expected to increase as expansion of the Urban Growth Boundary makes more land available for development. Currently, each jurisdiction addresses the impacts of development as they occur within its own boundary. However, the Johnson Creek Watershed extends across several jurisdictional boundaries, and environmental impacts are not confined to the jurisdiction of origin. The Johnson Creek Watershed Council was formed in 1992 to monitor and manage impacts across boundaries, on a watershed-wide basis. To operate effectively, the Council needs a way to establish two-way communication among all stakeholders in the watershed. A Land Use Network would help fill that need by providing a focal point for gathering and distributing land-use information. It would organize the information-gathering process, develop educational materials for public distribution, and organize the distribution channels. To develop the Land Use Network plan, the WNG researched the history of the watershed and its regulatory environment, theories of communication, and information on citizen participation networks. The WNG also conducted interviews and focus groups with current stakeholders to help clarify issues and identify communication needs that a Land Use Network might address. Finally, the WNG outlines a proposal for the Land Use Network. The proposal begins with a Network Structure diagram that illustrates the main elements of the Network Proposal. The elements of the Network Structure show how the Network can function effectively in the land use planning process. The issues, recommendations and actions provide methods for implementation for each element of the Network Structure. Finally, a summary of recommended actions shows the short-term, ongoing, and long-term implementation actions for the Network. This project was conducted under the supervision of Deborah Howe and Connie Ozawa. Title: A Land Use Network for the Johnson Creek Watershed Author: Caldwell, Jessica, Felton, Joyce, Redden, Elisa, Pagenstecher, Gerhard Year: 1998 This document presents a design for a Land Use Network. It is a starting point from which to build a network that connects, educates, and motivates stakeholders within the Johnson Creek Watershed to facilitate effective participation in the land use process. The Johnson Creek Watershed Council contracted the Watershed Network Group (WNG) to design the Network as a mechanism for organizing efforts to promote environmentally sound development throughout the watershed. The Johnson Creek Watershed Council comprises representatives from government, residents, and business organizations with interest in the Johnson Creek Watershed. The need for a Land Use Network within the watershed arose because existing methods of monitoring and managing the effects of development on the watershed are inadequate for meeting current development pressures. Development pressures on the watershed have had negative effects on the watershed environment. Development pressures are expected to increase as expansion of the Urban Growth Boundary makes more land available for development. Currently, each jurisdiction addresses the impacts of development as they occur within its own boundary. However, the Johnson Creek Watershed extends across several jurisdictional boundaries, and environmental impacts are not confined to the jurisdiction of origin. The Johnson Creek Watershed Council was formed in 1992 to monitor and manage impacts across boundaries, on a watershed-wide basis. To operate effectively, the Council needs a way to establish two-way communication among all stakeholders in the watershed. A Land Use Network would help fill that need by providing a focal point for gathering and distributing land-use information. It would organize the information-gathering process, develop educational materials for public distribution, and organize the distribution channels. To develop the Land Use Network plan, the WNG researched the history of the watershed and its regulatory environment, theories of communication, and information on citizen participation networks. The WNG also conducted interviews and focus groups with current stakeholders to help clarify issues and identify communication needs that a Land Use Network might address. Finally, the WNG outlines a proposal for the Land Use Network. The proposal begins with a Network Structure diagram that illustrates the main elements of the Network Proposal. The elements of the Network Structure show how the Network can function effectively in the land use planning process. The issues, recommendations and actions provide methods for implementation for each element of the Network Structure. Finally, a summary of recommended actions shows the short-term, ongoing, and long-term implementation actions for the Network. This project was conducted under the supervision of Deborah Howe and Connie Ozawa. Close

• 2. [Article] Streamflow Analysis and a Comparison of Hydrologic Metrics in Urban Streams

  This study investigates the hydrologic effects of urbanization in two Portland, Oregon streams through a comparison of three hydrologic metrics. Hydrologic metrics used in this study are the mean annual ...

  Citation × Citation Citation Abstract Copy Title: Streamflow Analysis and a Comparison of Hydrologic Metrics in Urban Streams Author: Wood, Matthew Lawton Year: 2012 This study investigates the hydrologic effects of urbanization in two Portland, Oregon streams through a comparison of three hydrologic metrics. Hydrologic metrics used in this study are the mean annual runoff ratio (Qa), mean seasonal runoff ratio (Qw and Qd), and the fraction of time that streamflow exceeds the mean streamflow during the year (TQmean). Additionally, the relative change in streamflow in response to storm events was examined for two watersheds. For this investigation urban development is represented by two urbanization metrics: percent impervious and road density. Descriptive and inferential statistics were used to evaluate the relationship between the hydrologic metrics and the amount of urban development in each watershed. The effect of watershed size was also investigated using nested watersheds, with watershed size ranging from 6 km2 to 138km 2. The results indicate that annual and seasonal runoff ratios have difficulty capturing the dynamic hydrologic behavior in urban watersheds. TQmean was useful at capturing the flashy behavior of the Upper Fanno watershed, however it did not perform as well in Kelley watershed possibly due to the influence of impermeable soils and steep slopes. Unexpected values for hydrologic metrics in Lower Johnson, Sycamore and Kelley watersheds could be the result water collection systems that appear to route surface water outside of their watersheds as well as permeable soils. Storm event analysis was effective at characterizing the behavior for the selected watersheds, indicating that shorter time scales may best capture the dynamic behavior of urban watersheds. Title: Streamflow Analysis and a Comparison of Hydrologic Metrics in Urban Streams Author: Wood, Matthew Lawton Year: 2012 This study investigates the hydrologic effects of urbanization in two Portland, Oregon streams through a comparison of three hydrologic metrics. Hydrologic metrics used in this study are the mean annual runoff ratio (Qa), mean seasonal runoff ratio (Qw and Qd), and the fraction of time that streamflow exceeds the mean streamflow during the year (TQmean). Additionally, the relative change in streamflow in response to storm events was examined for two watersheds. For this investigation urban development is represented by two urbanization metrics: percent impervious and road density. Descriptive and inferential statistics were used to evaluate the relationship between the hydrologic metrics and the amount of urban development in each watershed. The effect of watershed size was also investigated using nested watersheds, with watershed size ranging from 6 km2 to 138km 2. The results indicate that annual and seasonal runoff ratios have difficulty capturing the dynamic hydrologic behavior in urban watersheds. TQmean was useful at capturing the flashy behavior of the Upper Fanno watershed, however it did not perform as well in Kelley watershed possibly due to the influence of impermeable soils and steep slopes. Unexpected values for hydrologic metrics in Lower Johnson, Sycamore and Kelley watersheds could be the result water collection systems that appear to route surface water outside of their watersheds as well as permeable soils. Storm event analysis was effective at characterizing the behavior for the selected watersheds, indicating that shorter time scales may best capture the dynamic behavior of urban watersheds. Close

• 3. [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