The Assessment of Grid Resolution for Real-time Flood Warning in Urban area

According to the unique natural environment, Taiwan confronts a severe flood damage problem in typhoon seasons. Recently, due to global climate change and extreme weather, the prediction and prevention of flood damage becomes one of the most important research issues. The highly development area and densely concentrated population result in severe damage during flood occurs. Flood management and response plan become more important in metropolitan area. For the past two decades, the hydrological monitory and rainfall intense prediction techniques have a great progress in its accuracy. QPESUMS (Quantitative Precipitation Estimation and Segregation Using Multiple Sensors) developed by the Central Weather Bureau was applied to observe real-time Radar rainfall and its spatial distribution. DTM (Digital Terrain Model) and 2D inundation model which considers the blockage effect of buildings were applied to simulate the water depth in metropolitan area. In this study, Kaohsiung city is selected as the study area and typhoon Fanapi which makes tremendous flood damage in Southern Taiwan in 2010 is adopted as the study case. The main purpose of this study is to find the proper grid resolution of flood forecasting computations in Kaohsiung city from the evaluations of the efficiency and accuracy of three different resolutions.