The role of hydroclimate and water use on freshwater sustainability over the conterminous US.
Monday, 14 December 2015: 11:05
3011 (Moscone West)
A synthesis on freshwater sustainability is investigated across the conterminous US (CONUS). Spatio-temporal variability of potential drivers – hydroclimate and water use – influencing the freshwater sustainability are examined both individually as well as collectively by considering the eco-region and 4-digit Hydrologic Unit Code (HUC-4)as the spatial reference for the analysis. A detailed multivariate analysis relating the potential drivers with downstream flow anomalies indicate that changes in hydroclimate and water use adequately quantify the variability in downstream anomalies, but their signature varies significnatly across various regions of the CONUS. Results from the analysis indicate that both hydroclimatic extremes and mean annual fluxes control, but their signature alos vary across the CONUS. Among the changes in water use, irrigation water use predominantly carries the signature in explaining the downstream flow anomalies. To adequately express the sensitivity of downstream flow anomalies to hydroclimate and water use, we compute the elasticity of downstream flow anomalies to changes in hydroclimate and water use for each HUC8 regions of the US. Differences between the multivariate analysis and the elasticity estimates of freshwater sustainability are also discussed.