Integration of weather radar data into a raster GIS framework for improved flood estimation

Weather radar data were used to estimate rainfall fields at 2-km resolution for a large flood event in 1999 in south-east Queensland, Australia, and subsequently integrated with a raster-based hydrologic model (RAMS) for runoff generation and flow routing. Gauge-based and radar-based temporal storm patterns are quite similar for the storm event. Agreement between gauge-based and radar-based event rainfall totals is not as good as that for spatially averaged intensities. Correlation between gauge-based and radar-based rainfall measurements is not sensitive to the exponent value in the Z-R relationship for the event tested. The hydrologic model with 4 parameters for the entire 13 600-km(2) catchment works very well when calibrated against the measured hydrograph. An overall model efficiency of 0.61 is achieved with respect to predicted peak discharge for 17 validation sites in the catchment. RAMS compares favourably with URBS, a rainfall-runoff model using gauge-based measurements currently in use for flood forecasting purposes. Copyright (C) 2005 Royal Meteorological Society