Requirements for radar rainfall data in urban catchment modelling and control

Abstract

The use of radar rainfall data as input for storm runoff models can procure a real benefit if the hydrologic response of the watershed studied is strongly dependent on the spatial and temporal heterogeneity of precipitation over its area. In dynamic management of urban catchments rainfall runoff simulations are sensitive to the resolution of the input data. In this study the influence of varios time/space resolutions of radar rainfall data on the results of rainfall-runoff simulations is inverstigated. Therefore, X-band radar rainfall data with high resolution in space (0.5 × 0.5 km) and time (360° scan every second minute), are compared with radar data with 14 min time and 1 × 1 km space resolution as input for the HYSTEM/EXTRAN hydrodynamic model of a small urban catchment. The presented invstigations are realized within the research project “realtime control of a combined sewer system by radar estimates of precipitataon” carried out by the University of Hannover and the Emschergenossenschaft/Lippeverband.