Comparison of Raingauge&Calibrated Radar Data Using GIS Based Sewer Modelling

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 raingauge data.

The models have been simulated with rainfall data generated from RADAR data using various random reduction factors, point raingauge data and calibrated RADAR-raingauge 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-raingauge derived precipitation can give a better representation of the timing of flow response, total volume and peak depth in sewer networks.