HYDRA: A Geographical Information System for Sierra Nevada Watersheds

HYDRA Watersheds

This abstract was submitted to the American Water Resources Association Specialty Meeting on GIS & Water Resources 
HYDRA: A Geographical Information System for Sierra Nevada Watersheds
Viers J.H.,  A.M. King, and A. Geddes-Osborne
The UC Davis Center for Watershed Sciences is spearheading the largest climate change modeling exercise to focus specifically on the Sierra Nevada, California. Several modules to this exercise, including rainfall-runoff and stream temperature, rely on geospatial base data to drive their spatially-explicit parameterization. We describe HYDRA, a geographical information system of tabular and spatial data for 18 major basins of the Sierra Nevada, California. HYDRA was created for the purpose of characterizing the current status of Sierra Nevada watershed ecological integrity, to serve as the underlying basis for models depicting 2°, 4°, and 6° C warming, and providing standardized access to spatial physical, ecological, jurisdictional, hydrological, and meteorological data for the entire study region in an integrated framework. For example, we developed a watershed-scale index of riverine integrity to characterize the ecological state of all streams within the basin, which can be compared to future outcomes of rainfall-runoff scenarios. Our results indicated that hydrologic alteration from hydroelectric power operations had a significant negative influence on the integrity of streams as measured by both fish and benthic macroinvertebrate integrity indices; however, future sources of cold water may be dependent upon hydropower operations. HYDRA provides a robust and dynamic data store to be used in project evaluation, cross-basin comparative analyses, and scenario modeling of future conditions.