RAINFALL-RUNOFF ESTIMATION USING DIGITAL RADAR^*

Storm runoff is a concern to meteorologists and hydrological forecasters.A radar basin-based runoff algorithm is presented.The algorithm is based on the relationship between the rainfall over the basin and the discharge response at the gauge station.The algorithm is designed to provide runoff as a function of time for a given input(s) of rainfall.With known overflow levels,flood potential can also be evaluated.The runoff algorithm examined outflow at five basins within the operating scope of the Pittsburgh National Weather Service(NWS) radar.A comparison of the observed runoff was made with the algorithm generated discharge.In general,hydrograph accuracies improved with increasing rainfall excess.Possible reasons for discrepancies are examined.