HR: 0800h
AN: GC41A-0381    [Abstracts]
TI: Evaluation of precipitation products to force a global flood and drought prediction system
AU: * Voisin, N
EM: nathalie@hydro.washington.edu
AF: Department of Civil and Environmental Engineering, University of Washington, Wilson Ceramic Lab, Box 352700, Seattle, WA 98195-2700 United States
AU: Lettenmaier, D P
EM: dennisl@u.washington.edu
AF: Department of Civil and Environmental Engineering, University of Washington, Wilson Ceramic Lab, Box 352700, Seattle, WA 98195-2700 United States
AU: Wood, E F
EM: efwood@princeton.edu
AF: Department of Civil and Environmental Engineering, Princeton University, Princeton University, Princeton, NJ 08544 United States
AB: Droughts and floods are pervasive natural hazards. The annual cost of U.S. droughts is in the range $6-8B, and estimated U.S. annual flood losses are only slightly less. Global flood and drought losses are almost certainly much higher. Nonetheless, there is at present no system for forecasting of floods and droughts globally, although the potential now exists. The pilot phase of a project to generate global flood and drought predictions routinely is presented. It draws heavily from the experimental North American Land Data Assimilation System (N-LDAS) and the companion Global Land Data Assimilation System (G-LDAS) for development of nowcasts, and the University of Washington Experimental Hydrologic Prediction System to develop ensemble hydrologic forecasts based on the NCEP Global Forecast System for lead times from seven days to six months. In retrospective testing, the system, which uses the Variable Infiltration Capacity (VIC) macroscale hydrology model to make predictions of streamflow and soil moisture, is driven by the GPCP 1DD global precipitation products, and ECMWF surface air temperature products. Downward solar and longwave radiation, surface relative humidity, and other model forcings are derived from relationships with the daily temperature range. The initial system is implemented globally at one-half degree spatial resolution. Characteristics errors in the precipitation data into the hydrological model represent the best attainable forecasts, where errors are being estimated from differences between the GPCP 1DD, ERA-40 and a 50-year retrospective data set produced by the University of Washington and Princeton University. Differences in precipitation between the different global data sets and their resulting hydrological differences are evaluated for the 1997-2002 period for a number of major global rivers, and for specific events like the Mekong and Elbe River floods in 2002, the Mozambique floods in 2000, the Mozambique drought in 2001 and the recent western U.S. drought.
DE: 1812 Drought
DE: 1816 Estimation and forecasting
DE: 1821 Floods
DE: 1840 Hydrometeorology
DE: 1854 Precipitation (3354)
SC: Global Climate Change [GC]
MN: Fall Meeting 2005