レーダー雨量の逐次補正とその洪水予測への適用

Abstract

Radar raingauges can instantaneously measure precipitation over the broad area.To make good use of this characteristic for flood forecasting, the authors considerfive methods of calibrating the parameters B and B in the radar equations whichtransform the received power into the rainfall intensity. The rainfall measured by aradar is corrected in real time through the calibration using the hourly rainfallsmeasured by many raingauges on the ground in the drainage basin.The aim of this research is to improve the accuracy of flood runoff forecastingby improving the estimation accuracy of areal rainfalls through the real-time cali-bration. Using the existing rainfall and discharge data in the Yura River basin(1880 km2) and rainfall data obtained by the Miyama Radar Raingauge System, the ac-curacies of flood forecasting based on the five calibrations are compared with thosebased on the situations using only raingauge data (not using radar) and using onlythe radar data (no-calibration situation).