NHDPlus Western States Snowpack Analysis Framework for Current Conditions and Impacts from Climate Change

Larger river systems in the western United States receive their base flow from snowpack in higher elevation areas. Extended drought episodes can reduce the release of water from the major snowpack zones, and climate change may lead to more chronic impacts on water availability. The enhanced National Hydrography Dataset (the NHDPlus) can be applied to provide a nationally consistent framework to define the extent of the western snowpack core areas. Once the periphery (or rim) of a core snowpack zone is defined within the NHDPlus, upstream and downstream analyses can be applied for units ranging from small local watersheds to large hydrological networks implemented for all U.S. western states. Examples are provided illustrating the methods for developing this NHDPlus-based snowpack framework and ways in which analytical data mining and modeling tools can assist in water quality and quantity management programs to address climate change impacts.