Prevention work in the watersheds is the most important task, explains Chin Kuo. The 921 quake left open gashes on the face of many mountains in central Taiwan. Whenever there was heavy rain, the exposed soil and rocks would flow downstream.
源頭整治的部分最重要，許多山頭被震出裂縫，一旦遇上大雨，裂縫中的土石，就會形成土石流一路衝到下游來，自然工法便在坡頂源頭及稜線地帶尋找大地的裂縫，將其填補起來。