都市積淹水即時預報可減少颱風梅雨等劇烈降水天氣所造成的生命財產損失，因為正確而精密的降雨觀測資料為水文模式最重要的上游資料之ㄧ，降雨觀測和極短預測的時空解析度和正確性要求極高，透過研發取得時空解析度和準確度高的降雨觀測，可減少降雨不確定性造成降雨－逕流轉換關係的誤差，以及「都市積淹水即時預報」系統推估「下水道水位」和「淹水潛勢」的誤差。從雷達氣象研究顯示偏極化雷達可提供較傳統都卜勒雷達更準確的降雨率，因此本計劃本年將以中央大學C 波段偏極化雷達進行策略。第一階段以不同掃瞄策略觀測台北盆地各類型降雨型態案例，比對雷達觀測數據和雨量站、以及於目標地區設置的雨滴譜儀的觀測數據，檢校雙偏極化雷達推估降水強度參數，研擬最佳化掃描策略。第二階段則配合都市集水區和周邊山區小集水區降雨－逕流關係的密集水文試驗，整合C-波雙偏極化雷達觀測、五分山S-波段雷達及地面觀測數據，提供時間與空間高解析度的精密降水估計。本年研究重點：研擬最佳化雷達掃瞄策略。在發生颱風、雷陣雨、梅雨和鋒面雨等降水類型事件個案時，以中央大學雙偏極化雷達，執行不同觀測仰角與仰角數的掃描策略，取得可供分析的觀測數據。在目標研究區域－台北市玉成抽水站集水區範圍，找尋適當地點，長期設置一至二個雨滴譜儀，配合雙偏極化雷達觀測，輔助解釋雷達觀測數據。從大氣科學觀點分析各種雷達掃描策略，比較其觀測不同降水系統的優勢與劣勢，以及發展即時（外延）預報的效益，研擬一至數種最佳化掃瞄策略。 ; This sub - project , “ the strategy study of the Polarimetric radar quantitative precipitation estimate.” will be one of the most important upstream input for the other subjects of the main project “Urban Inundation-Potential Nowcasting System, A Pilot Study”. Since the severe damage of human casualty and property caused by the flash flood within the cities of Taiwan, this project will provide high time and spatial resolution rainfall product from the dual-polarimetric radar observation as the input of the models which calculate the flood water level from an sophisticated Unban Inundation-Potential Nowcasting model. Because these hydro-models need very accurate rainfall in very high resolution, the observation scanning strategy and data processing will be tested to achieve the most optimum strategy, such as different time interval, elevation angles, scanning speeds, radial resolutions and different products. In the first year the NCU C-pol and disdrometes will be the major instruments, project will carry out observation in different weather systems, specially, the typhoons, Meiyu fronts and mesoscale convective storm, and severe local thunderstorm. Project will also provide the rainfall difference analysis between the poalrimetric radar, ordinary Doppler radar and the disdtrometer.. The close interaction with other related sub-project and the dialog between each sub-projects will also be one of the important task of this project to insure the application. ; 研究期間 9708 ~ 9807
