The Influence of Terrain on the Tropical Rainfall Potential Technique in Taiwan

The tropical rainfall potential (TRaP) technique is a simple concept that serves as a useful tool for forecasters in predicting the accumulated rainfall from typhoons. This research seeks to propose an algorithm for improving the accuracy of the results retrieved from the TRaP technique by taking into account the terrain's influence on a typhoon's rainfall pattern over Taiwan. The climatological percentages of the accumulated rainfall in Taiwan for six different typhoon tracks were established via statistical methods. By using the rainfall percentages with the original TRaP technique, results showed that the original TRaP technique could retrieve a graphical representation of the accumulated rainfall from typhoons for both oceans and flat land areas. When factoring in Taiwan's terrain, the accuracy in a typhoon's accumulated rainfall estimation is seen to further improve.