HR: 0800h
AN: H31G-0747    [Abstracts]
TI: Synergies Between Changes in Climate, Land Cover/Use, and Streamflow Regulation, in the Mekong River Basin
AU: * Costa-Cabral, M C
EM: cabral@hydrologyfutures.com
AF: Hydrology Futures, 1612 N 39 St, Seattle, WA 98103, United States
AU: Richey, J E
EM: jrichey@u.washington.edu
AF: University of Washington School of Oceanography, Box 357940, Seattle, WA 98195, United States
AU: Lettenmaier, D P
EM: lettenma@u.washington.edu
AF: University of Washington Department of Civil & Environmental Engineering, Box 352700, Seattle, 98195, United States
AU: Beyene, T K
EM: tazebe@hydro.washington.edu
AF: University of Washington Department of Civil & Environmental Engineering, Box 352700, Seattle, 98195, United States
AB: How a changing climate will interact synergetically with land cover and use change and streamflow regulation to impact the hydrologic regime of a particular river basin is an open research question with important implications for society's adaptation and planning. We take the case of the Mekong, the largest river basin in Southeast Asia (circa 800,000 km2) and evaluate its combined response to these three pressures. We use the Variable Infiltration Capacity macro-scale hydrologic model, which explicitly accounts for differences in land cover, coupled with a model of reservoir operation, to simulate streamflows under scenarios of land cover/use and climate change. The changed climate is represented by perturbing the historical climatology according to the results of an ensemble of global climate models. Our results reveal important synergetic relationships between all three pressures, and major differences in response between seasons. For example, where both the precipitation and temperature are expected to rise, the simulated streamflow response of a subbasin may be an increase or a decrease, depending on the subbasin's average seasonal temperature (colder subbasins being generally more sensitive to temperature rises), and depending on the degree of conversion of forest to agriculture. While reservoir operation is a dominant pressure during the dry season, it is dependent to considerable degree on the changes in incoming streamflow determined by land cover/use and climate changes.
DE: 1632 Land cover change
DE: 1805 Computational hydrology
DE: 1807 Climate impacts
DE: 1808 Dams
DE: 1842 Irrigation
SC: Hydrology [H]
MN: 2007 Fall Meeting