Using Local Weather Radar Data for Sewer System Modeling: Case Study in Flanders, Belgium

Abstract

Contemporary sewer system operation heavily relies on urban drainage model results. In a case study near Leuven, Belgium, this research investigates the potential of a cost-effective local area weather radar (LAWR) for providing rainfall input to sewer models. Before rainfall estimation was possible, the radar was calibrated using tipping bucket rain gauge measurements. Various calibration methods were investigated, and a nonlinearly regressed power law function taking range to the radar into account was most suitable in this case study. Rainfall estimations could be slightly improved by rendering the calibration dependent on radar output. Fifty-seven events were simulated using the InfoWorks CS modeling software, and the effect of radar input on model results was investigated. There were large quantitative deviations, but the qualitative course of time series observed in conduits was reproduced well. Although certain events show a higher correspondence between measured and simulated time series when using radar-driven input, the gauge-driven input generally outperforms the former in this case study and the accompanying model.