Comparison of Raingauge & Radar-Raingauge Derived Precipitation on GIS Based Sewer Modelling

摘要

Accurate real-time rainfall measurement is an important aspect in sewer network modelling. Weather Radio Detection and Ranging (RADAR) can give a good estimate of precipitation as compared to Tipping Bucket data. The RADAR data should be properly processed to make it usable for calibration purposes. This paper presents ways in which the discrepancies in RADAR data can be minimised by determining a relationship between RADAR and Tipping Bucket rainguage data. The models have been simulated with rainfall data generated from RADAR data using various random reduction factors, point rainguage data and calibrated RADAR-rainguage derived precipitation. The paper reports on the results of these trials, indicating the differences in using the above methods. Results show that the calibrated RADAR-rainguage derived precipitation can give a better representation of the timing of flow response, total volume and peak depth in sewer networks.