Mountain Hydrology, Forest Management And Water Security In The Sierra Nevada
Bales, Roger C 1
1 Sierra Nevada Research Institute, University of California, Merced
Water security is the reliable availability of an acceptable quantity & quality of water for health, livelihoods and production, coupled w/ an acceptable level of water-related risks. California has in the past and can in the future maintain its high level of water security through a combination of adequate infrastructure to store treat and transport water, plus strong and adaptable institutions. However, pressures of climate change and growing demand on a fixed or diminishing water resource raise the importance of managing of ecosystem services that affect water supply. Fire suppression policies of the past century have resulted in high and non-sustainable forest densities in the Sierra Nevada, with accompanying impacts on the mountain water cycle. These forests have high rates of evapotranspiration, owing to high precipitation rates, plus sufficient snowpack and subsurface storage to sustain year-round growth. Recent results from the Southern Sierra Critical Zone Observatory and other field sites provide a basis for quantitative predictions of how water storage, evapotranspiration and runoff across the climate and ecosystem zones of the Sierra Nevada will respond to a warming climate, fire and vegetation management.