Mountain torrent (JOESCO Bastion) precursory phenomena happened mostly has close relation with rainfall intensity.

1. The mountain trees rustle slightly disturbing noise, mountain mountain of abnormal sound.

2. Water level within a gulley decreased dramatically.

3. The gulley very turbid water.

4. There are abnormal smell.

5. With trees tearing sound.

6. Animals have abnormal behavior, such as a cat's a loud whinny.