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• 11. [Article] Climate Change and Shifts in Water Related Ecosystem Services in the Tualatin and Yamhill River Basins

  Water related ecosystem services (WES), such as flow regulation, drinking water supply, temperature regulation, and water recreational activities, are affected by anthropogenic climate change. Forecasting ...

  Citation × Citation Citation Abstract Copy Title: Climate Change and Shifts in Water Related Ecosystem Services in the Tualatin and Yamhill River Basins Author: Chang, Heejun, Anthony, Terrance, Ennaanay, Driss, Sharma, Manu Year: 2011 Water related ecosystem services (WES), such as flow regulation, drinking water supply, temperature regulation, and water recreational activities, are affected by anthropogenic climate change. Forecasting potential shifts in such WES is critical to identifying the form and magnitude of likely impacts. We quantified the levels and values of WES under multiple climate change scenarios in the two watersheds located in the Portland metropolitan area, Oregon, USA using the combination of a hydrologic model Better Assessment Science Integrating point and Non-point Sources - Soil and Water Assessment Tool (BASINS-SWAT) and an ecosystem evaluation model ? Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST). Using the Intergovernmental Panel on Climate Change?s AR4 climate change simulation results, we found that there is a slight relative increase in annual water yield, sediment yield, and dissolved phosphorus, but storm peak management does not change substantially by the 2050s. Spatial analysis shows that the locations of hot and cold spots remain relatively stable. It is also shown that there are high spatial and temporal uncertainties associated with climate change projections due to variations in precipitation projections toward the middle of the 21st century. The findings of our study provide useful information for water and land managers in identifying target areas for conservation to best sustain WES provision, use, and value under a range of climate change scenarios. Title: Climate Change and Shifts in Water Related Ecosystem Services in the Tualatin and Yamhill River Basins Author: Chang, Heejun, Anthony, Terrance, Ennaanay, Driss, Sharma, Manu Year: 2011 Water related ecosystem services (WES), such as flow regulation, drinking water supply, temperature regulation, and water recreational activities, are affected by anthropogenic climate change. Forecasting potential shifts in such WES is critical to identifying the form and magnitude of likely impacts. We quantified the levels and values of WES under multiple climate change scenarios in the two watersheds located in the Portland metropolitan area, Oregon, USA using the combination of a hydrologic model Better Assessment Science Integrating point and Non-point Sources - Soil and Water Assessment Tool (BASINS-SWAT) and an ecosystem evaluation model ? Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST). Using the Intergovernmental Panel on Climate Change?s AR4 climate change simulation results, we found that there is a slight relative increase in annual water yield, sediment yield, and dissolved phosphorus, but storm peak management does not change substantially by the 2050s. Spatial analysis shows that the locations of hot and cold spots remain relatively stable. It is also shown that there are high spatial and temporal uncertainties associated with climate change projections due to variations in precipitation projections toward the middle of the 21st century. The findings of our study provide useful information for water and land managers in identifying target areas for conservation to best sustain WES provision, use, and value under a range of climate change scenarios. Close

• 12. [Article] Assessing Mechanisms of Climate Change Impact on the Upland Forest Water Balance of the Willamette River Basin, Oregon

  Projected changes in air temperature, precipitation, and vapor pressure for the Willamette River Basin (Oregon, USA) over the next century will have significant impacts on the river basin water balance, ...

  Citation × Citation Citation Abstract Copy Title: Assessing Mechanisms of Climate Change Impact on the Upland Forest Water Balance of the Willamette River Basin, Oregon Author: Turner, David P., Conklin, David R., Vache, Kellie B., Schwartz, Cynthia, Nolin, Anne, Chang, Heejun, Watson, Eric, Bolte, John P. Year: 2016 Projected changes in air temperature, precipitation, and vapor pressure for the Willamette River Basin (Oregon, USA) over the next century will have significant impacts on the river basin water balance, notably on the amount of evapotranspiration (ET). Mechanisms of impact on ET will be both direct and indirect, but there is limited understanding of their absolute and relative magnitudes. Here, we developed a spatially explicit, daily time-step, modeling infrastructure to simulate the basin-wide water balance that accounts for meteorological influences, as well as effects mediated by changing vegetation cover type, leaf area, and ecophysiology. Three CMIP5 climate scenarios (Lowclim, Reference, and HighClim) were run for the 2010–2100 period. Besides warmer temperatures, the climate scenarios were characterized by wetter winters and increasing vapor pressure deficits. In the mid-range Reference scenario, our landscape simulation model (Envision) projected a continuation of forest cover on the uplands but a threefold increase in area burned per year. A decline (12–30%) in basin-wide mean leaf area index (LAI) in forests was projected in all scenarios. The lower LAIs drove a corresponding decline in ET. In a sensitivity test, the effect of increasing CO2 on stomatal conductance induced a further substantial decrease (11–18%) in basin-wide mean ET. The net effect of decreases in ET and increases in winter precipitation was an increase in annual streamflow. These results support the inclusion of changes in land cover, land use, LAI, and ecophysiology in efforts to anticipate impacts of climate change on basin-scale water balances. Title: Assessing Mechanisms of Climate Change Impact on the Upland Forest Water Balance of the Willamette River Basin, Oregon Author: Turner, David P., Conklin, David R., Vache, Kellie B., Schwartz, Cynthia, Nolin, Anne, Chang, Heejun, Watson, Eric, Bolte, John P. Year: 2016 Projected changes in air temperature, precipitation, and vapor pressure for the Willamette River Basin (Oregon, USA) over the next century will have significant impacts on the river basin water balance, notably on the amount of evapotranspiration (ET). Mechanisms of impact on ET will be both direct and indirect, but there is limited understanding of their absolute and relative magnitudes. Here, we developed a spatially explicit, daily time-step, modeling infrastructure to simulate the basin-wide water balance that accounts for meteorological influences, as well as effects mediated by changing vegetation cover type, leaf area, and ecophysiology. Three CMIP5 climate scenarios (Lowclim, Reference, and HighClim) were run for the 2010–2100 period. Besides warmer temperatures, the climate scenarios were characterized by wetter winters and increasing vapor pressure deficits. In the mid-range Reference scenario, our landscape simulation model (Envision) projected a continuation of forest cover on the uplands but a threefold increase in area burned per year. A decline (12–30%) in basin-wide mean leaf area index (LAI) in forests was projected in all scenarios. The lower LAIs drove a corresponding decline in ET. In a sensitivity test, the effect of increasing CO2 on stomatal conductance induced a further substantial decrease (11–18%) in basin-wide mean ET. The net effect of decreases in ET and increases in winter precipitation was an increase in annual streamflow. These results support the inclusion of changes in land cover, land use, LAI, and ecophysiology in efforts to anticipate impacts of climate change on basin-scale water balances. Close

• 13. [Article] Analysis of Long-Term Climate Change on Per Capita Water Demand in Urban Versus Suburban Areas in the Portland Metropolitan Area, USA

  We investigated the impacts of long-term climate variability and change on per capita water demand in urban and suburban service areas that have different degrees of development density in the Portland ...

  Citation × Citation Citation Abstract Copy Title: Analysis of Long-Term Climate Change on Per Capita Water Demand in Urban Versus Suburban Areas in the Portland Metropolitan Area, USA Author: Parandvash, G. Hossein, Chang, Heejun Year: 2016 We investigated the impacts of long-term climate variability and change on per capita water demand in urban and suburban service areas that have different degrees of development density in the Portland metropolitan area, USA. Together with historical daily weather and water production data, socioeconomic data such as population and unemployment rate were used to estimate daily per capita water demand in the two service areas. The structural time series regression model results show that the sensitivity of per capita water demand to both weather and unemployment rate variables is higher in suburban areas than in urban areas. This is associated with relatively higher proportional demand by the residential sector in the suburban area. The estimated coefficients of the historical demand model were used to project the mid-21st century (2035–2064) per capita water demand under three climate change scenarios that represent high (HadGEM2-ES), medium (MIROC5), and low (GFDL) climate changes. Without climate adaptation, compared to the historical period between 1983 and 2012, per capita water demand is projected to increase by 10.6% in the 2035–2064 period under the HadGEM2-ES in suburban areas, while per capita demand is projected to increase by 4.8% under the same scenario in urban areas. Our findings have implications for future urban water resource management and land use planning in the context of climate variability and change. A tight integration between water resource management and urban planning is needed for preparing for climate adaptation in municipal water planning and management. Title: Analysis of Long-Term Climate Change on Per Capita Water Demand in Urban Versus Suburban Areas in the Portland Metropolitan Area, USA Author: Parandvash, G. Hossein, Chang, Heejun Year: 2016 We investigated the impacts of long-term climate variability and change on per capita water demand in urban and suburban service areas that have different degrees of development density in the Portland metropolitan area, USA. Together with historical daily weather and water production data, socioeconomic data such as population and unemployment rate were used to estimate daily per capita water demand in the two service areas. The structural time series regression model results show that the sensitivity of per capita water demand to both weather and unemployment rate variables is higher in suburban areas than in urban areas. This is associated with relatively higher proportional demand by the residential sector in the suburban area. The estimated coefficients of the historical demand model were used to project the mid-21st century (2035–2064) per capita water demand under three climate change scenarios that represent high (HadGEM2-ES), medium (MIROC5), and low (GFDL) climate changes. Without climate adaptation, compared to the historical period between 1983 and 2012, per capita water demand is projected to increase by 10.6% in the 2035–2064 period under the HadGEM2-ES in suburban areas, while per capita demand is projected to increase by 4.8% under the same scenario in urban areas. Our findings have implications for future urban water resource management and land use planning in the context of climate variability and change. A tight integration between water resource management and urban planning is needed for preparing for climate adaptation in municipal water planning and management. Close

• 14. [Article] Water Supply, Demand, and Quality Indicators for Assessing the Spatial Distribution of Water Resource Vulnerability in the Columbia River Basin

  We investigated water resource vulnerability in the US portion of the Columbia River basin (CRB) using multiple indicators representing water supply, water demand, and water quality. Based on the US county ...

  Citation × Citation Citation Abstract Copy Title: Water Supply, Demand, and Quality Indicators for Assessing the Spatial Distribution of Water Resource Vulnerability in the Columbia River Basin Author: Chang, Heejun, Jung, Il-Won, Strecker, Angela L., Wise, Daniel, Lafrenz, Martin, Shandas, Vivek, Moradkhani, Hamid, Yeakley, J. Alan, Pan, Yangdong, Bean, Robert Allen, Johnson, Gunnar, Psaris, Mike Year: 2013 We investigated water resource vulnerability in the US portion of the Columbia River basin (CRB) using multiple indicators representing water supply, water demand, and water quality. Based on the US county scale, spatial analysis was conducted using various biophysical and socio-economic indicators that control water vulnerability. Water supply vulnerability and water demand vulnerability exhibited a similar spatial clustering of hotspots in areas where agricultural lands and variability of precipitation were high but dam storage capacity was low. The hotspots of water quality vulnerability were clustered around the main stem of the Columbia River where major population and agricultural centres are located. This multiple equal weight indicator approach confirmed that different drivers were associated with different vulnerability maps in the sub-basins of the CRB. Water quality variables are more important than water supply and water demand variables in the Willamette River basin, whereas water supply and demand variables are more important than water quality variables in the Upper Snake and Upper Columbia River basins. This result suggests that current water resources management and practices drive much of the vulnerability within the study area. The analysis suggests the need for increased coordination of water management across multiple levels of water governance to reduce water resource vulnerability in the CRB and a potentially different weighting scheme that explicitly takes into account the input of various water stakeholders. Title: Water Supply, Demand, and Quality Indicators for Assessing the Spatial Distribution of Water Resource Vulnerability in the Columbia River Basin Author: Chang, Heejun, Jung, Il-Won, Strecker, Angela L., Wise, Daniel, Lafrenz, Martin, Shandas, Vivek, Moradkhani, Hamid, Yeakley, J. Alan, Pan, Yangdong, Bean, Robert Allen, Johnson, Gunnar, Psaris, Mike Year: 2013 We investigated water resource vulnerability in the US portion of the Columbia River basin (CRB) using multiple indicators representing water supply, water demand, and water quality. Based on the US county scale, spatial analysis was conducted using various biophysical and socio-economic indicators that control water vulnerability. Water supply vulnerability and water demand vulnerability exhibited a similar spatial clustering of hotspots in areas where agricultural lands and variability of precipitation were high but dam storage capacity was low. The hotspots of water quality vulnerability were clustered around the main stem of the Columbia River where major population and agricultural centres are located. This multiple equal weight indicator approach confirmed that different drivers were associated with different vulnerability maps in the sub-basins of the CRB. Water quality variables are more important than water supply and water demand variables in the Willamette River basin, whereas water supply and demand variables are more important than water quality variables in the Upper Snake and Upper Columbia River basins. This result suggests that current water resources management and practices drive much of the vulnerability within the study area. The analysis suggests the need for increased coordination of water management across multiple levels of water governance to reduce water resource vulnerability in the CRB and a potentially different weighting scheme that explicitly takes into account the input of various water stakeholders. Close