HR: 11:50h
AN: H22D-07    [Abstracts]
TI: Central American climate change consensus and implications for Rio Lempa streamflow
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
AU: Wood, A W
EM: aww@u.washington.edu
AF: University of Washington Department of Civil and Environmental Engineering, Box 352700, Seattle, WA 98195-2700, United States
AB: We combine 21st century projections from 32 global climate model (GCM) simulations produced for the Intergovernmental Panel on Climate Change Fourth Assessment, 16 GCMs each using both the lower SRES B1 and the higher SRES A2 greenhouse gas emissions scenarios. We use an established statistical downscaling procedure to produce sequences of precipitation and temperature over the Rio Lempa basin, the largest river system in Central America and an important resource for water supply and hydropower generation. We use a spatially distributed hydrologic model to integrate these climate projections into streamflow. Assuming each projection is equally probable, we examine the level of consensus among model projections for each emissions scenario for precipitation, temperature, and streamflow. For the end of the 21st century, the basin has a median temperature increase of 3.4C under A2 and 1.9C under B1, both of which are highly significant and significantly different. Annual rainfall declines by 10 percent under A2 and 5 percent under B1. Rainfall decreases are highly significant, as are differences between A2 and B1 for April-June. With the projected drying occurring in the early rainy season, the bimodal characteristic of the rainy season becomes less pronounced. GCMs projecting greater warming tend to project drier conditions than those projecting less warming. The consensus of the projections is for a seasonal shift in Rio Lempa flows, with annual flows dropping by 13 percent under lower emissions and 24 percent under higher emissions, with the peak flow decrease of 35-40 percent in June-August, months during which reservoir refilling has historically occurred.
UR: http:www.engr.scu.edu/~emaurer
DE: 1637 Regional climate change
DE: 1655 Water cycles (1836)
DE: 1807 Climate impacts
DE: 1857 Reservoirs (surface)
DE: 1880 Water management (6334)
SC: Hydrology [H]
MN: 2007 Joint Assembly