颱風豪雨經常引發堤防潰堤而使河水泛濫，或者颱風伴隨豪大雨遇到中央山脈的陡峭地形而引發土石流，這些都會造成台灣地區嚴重的氣象及水文災害。本計畫擬討論侵台颱風所引發的地形降水議題，包括中央山脈如何改變登陸颱風環流的降水物理過程與降水粒子收支平衡(water budget)、以及颱風豪雨導致的急速河川逕流變化。首先本計畫將就以納莉(2001)颱風為主要研究個案，針對MM5 數值模擬結果進行模式診斷分析及敏感度測試實驗，探討台灣地形如何改變納莉颱風的雲微物理過程，比較納莉颱風登陸前後之水收支平衡(water budget)。本計畫並發展大氣模式(MM5)及水文模式(FLO-2D)的耦合模式，以探討颱風豪雨如何導致河川逕流（洪水）之迅速變化。最後嘗試將研究結果應用於其他颱風個案中。The heavy rainfalls associated with landfalling typhoons often induce flooding over the river basin or landslide over steep topographic regions, and both situations are the most severe meteorological and hydrological damages over the Taiwan area. In next three years (2008-2011), we will continue our previous efforts to investigate serveal scientific issues of orographic precipitation induced by landfalling typhoons. These issues include how the Central Mountain Range modifies the precipitation physical processes and water budget within the typhoon circultation, and the rapid river runoff variations triggered by typhoon’s heavy rainfalls. First, we will continue our series of MM5 sensitivity experiments and model diagnostics of Typhoon Nari (2001) to investigate how Taiwan terrain affects the microphysical processes, and compare Nari’s water budget before and after its landfall on Taiwan. Second, we will couple the typhoon model (MM5) with a river runoff model (FLO-2D) to study how typhoon-induced heavy rainfalls affect stream flow and discharge. Finally, we will extend our research results of Typhoon Nari to other landfalling typhoon cases. 研究期間：9908 ~ 10007
