Accuracy Evaluation of Radar Rainfall by A Rainfall-Runoff Model

초록

From the late of 1990’s, the localized strong storm events were frequently occurred and flood damage is increasing trend in Korea. In order to reduce the flood damage caused by heavy rainfall, we may need more accurate observation of rainfall and flood analysis for preparing for flood prevention measures. The measurement errors exist in rainfall data observed by rain gauge and the precise observation and prediction of rainfall by rain gauge could be difficult due to the change of storm event in space and time. So the study on radar rainfall has been highlighted for more accurate rainfall measurement especially for spatial distribution and movement of rainfall. The rainfall is used as the input data in rainfall-runoff model for hydrologic analysis such as floods and so the reduction study of rainfall errors which can be occurred should be performed for obtaining more precise input data. However, most researches related to radar rainfall have been focused on radar data acquisition and meteorological quality control. This study tried to study the methods of accuracy evaluation and to do the test of radar rainfall for hydrological applications. First, we performed the radar rainfall adjustment based on the measured rainfall by rain gauge using G/R, Sophisticated method(SOA), and so on. Then we used a rainfall-runoff model called Vflo model in order to verify the accuracy and distribution of the adjusted rainfall. Say, the runoff is simulated by using the adjusted rainfall and the model and the simulated runoff is compared with the observed runoff. Also, the statistical analysis is used for the derivation of evaluation index which can evaluate the accuracy of radar rainfall. Therefore, the procedure for the accuracy assessment and verification of radar rainfall data suggested in this study could be utilized for hydrological application. Acknowledgement: This study was financially supported by the Construction Technology Innovation Program(08-Tech-Inovation-F01)