Colorado River Basin Streamflow Projection Under IPCC CMIP5 Scenariors
The Colorado River is the dominant water supply source for the Southwest U.S. Recent climate change studies for the region project a dire future, with chronic drought and substantially reduced Colorado River flows. The proposed project contains both regional climate and hydrologic modeling components designed to retrospectively diagnose and project streamflow in the Colorado River sub-basins, accounting for both natural variability and anthropogenic climate change. Particularly, whether there will be a synergistic relationship between the occurrence of extreme wet or dry conditions and the natural variability of El Nino Southern Oscillation and Pacific Decadal Variability is of high interest. The main objective of this project is to characterize how the changing climate of the Southwest is affecting cool and warm season precipitation in the Colorado River basin and the corresponding response of streamflow in individual sub-basins. The project will address the projection of future water resources in the Colorado River basin with a physically-based modeling approach. The project incorporates dynamical downscaling and hydrologic modeling components. With dynamical downscaling, a regional atmospheric model will be forced with data from a courser resolution global model (grid spacing of hundreds of kilometers) to create climate information at a more regionalized scale (grid spacing of single to tens of kilometers). Hydrologic modeling will be performed using the Variable Infiltration Capacity (VlC) model (Liang et al., 1994) and will include the representation of subgrid scale variability in vegetation coverage, topography, precipitation, and soil moisture storage capacity. Regional climate modeling will add substantial value in the climatological representation of both cool and warm season precipitation in the Southwest (e.g. Dominguez et al. 2012; Castro et al. 2012). The results from the regional climate projections produced by this project will provide a long-term (100 years and longer) continuous modeling product for both United States and Mexico. These regional scale climate projections will produce information at a more relevant spatial scale for decision making. They are also more applicable for use in applications of other disciplines, such as hydrology and ecology, which are in need of finer resolution long-term climate models. Hydrology streamflow projections for the selected river sub-basins will provide valuable guidance for in water resource planning for both Colorado basins.
Office: Bureau of Reclamation
Grants Officer
Phone 702-293-8570
