HR: 15:25h
AN: H23H-08    [Abstracts]
TI: Modeling of land surface processes in La Plata Basin
AU: * Su, F
EM: fgsu@hydro.washington.edu
AF: Department of Civil and Environmental Engineering, Box 352700 University of Washington, Seattle, WA 98195-2700 United States
AU: Lettenmaier, D P
EM: dennisl@u.washington.edu
AF: Department of Civil and Environmental Engineering, Box 352700 University of Washington, Seattle, WA 98195-2700 United States
AU: Barros, V R
EM: barros@at.fcen.uba.ar
AF: Department of Atmospheric and Oceanic Sciences, University of Buenos Aires, Buenos Aires, 1428 Argentina
AU: Tucci, C E
EM: tucci@portoweb.com.br
AF: Instituo de Pesquisas Hidraulicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, 915010970 Brazil
AU: Berbery, E
EM: berbery@atmos.umd.edu
AF: Department of Meteorology, University of Maryland at College Park, College Park, MD 20742-2425 United States
AB: The La Plata Basin is the second largest river (in discharge) in the Americas. Its mean discharge exceeds that of the Mississippi by about 20%, with a drainage area that is slightly smaller. The basin covers parts of five South American countries and plays a critical role in energy production, water resources, transportation, agriculture, and livestock production of the region. Significant changes in precipitation and discharge of many tributaries of La Plata have raised questions as to the relative roles of remote climate forcings (e.g., Atlantic and Pacific Ocean conditions) and land cover change as the proximate causes. Macroscale hydrology models provide a useful approach for understanding the nature and cause of these changes. We describe an application of the Variable Infiltration Capacity (VIC) macroscale hydrology model to simulate the land surface water balance of La Plata basin and its major tributaries, and to diagnose long-term changes. The VIC forcing data sets, which consist of daily time-series of precipitation, maximum temperature, minimum temperature, and wind speed from 1979 through 1999, were developed at 0.125›X (total 18641 grid cells). Daily precipitation and temperature were gridded from station data, and wind speed was downscaled from the NCEP/NCAR reanalysis. Prior to assessing the water balance simulations of the VIC model, the gridded precipitation from daily station data was aggregated to monthly, and compared with previously developed data sets to assure consistency. A 0.125›X 0.125›X river network based on 1 km DEM is the basis for routing VIC surface and subsurface runoff to produce simulated streamflows. The modeled water balance was evaluated with streamflow records from the three major subbasins of La Plata: the Parana, Paraguay, and Uruguay Rivers.
DE: 1846 Model calibration (3333)
DE: 1847 Modeling
DE: 1854 Precipitation (3354)
DE: 1860 Streamflow
DE: 1876 Water budgets
SC: Hydrology [H]
MN: Fall Meeting 2005