HR: 1340h
AN: H43B-0498    [Abstracts]
TI: Uncertainty in Hydrologic Impacts of Climate Change over California's Sierra Nevada Mountains
AU: * Maurer, E P
EM: emaurer@engr.scu.edu
AF: Santa Clara University Civil Engineering Department, 500 El Camino Real, Santa Clara, CA 95053-0563 United States
AB: The streams that flow from California's Sierra Nevada Mountains supply a major portion of the managed water in the state. These streams are showing discernable changes consistent with a warming climate, and continued warming over the next century will have dramatic effects. Projections of future climate assume different levels of greenhouse gas emissions, and this study compares the impacts on California hydrology of the highest (A2) and lowest (B1) emissions scenarios currently available for the climate models participating in the IPCC AR4 simulations. For each emissions scenario, the projected changes in future precipitation and temperature simulated by 11 global climate models are statistically downscaled, and then used to drive a hydrologic model to simulate the land surface hydrology of California. Although there is considerable variability among the climate models in the projected climate, the temperature changes greatly exceed inter-model variability, and are highly significant even early in the 21st century. Increases in winter and decreases in spring precipitation also exceed inter-model variability, with higher significance for the higher emissions scenario. Although hydrologic impacts are large under both scenarios, the differences in certain impacts between higher and lower emissions pathways are large compared to inter-model variability, especially on seasonal streamflow timing at high elevations. This implies a potential value of reducing emissions early to reduce future mitigation costs associated with adapting to hydrologic impacts of climate change.
UR: http://www.engr.scu.edu/~emaurer
DE: 1630 Impacts of global change (1225)
DE: 1637 Regional climate change
DE: 1655 Water cycles (1836)
DE: 1807 Climate impacts
DE: 1873 Uncertainty assessment (3275)
SC: Hydrology [H]
MN: Fall Meeting 2005