Before the earthquake there occurs obviously a regular variation of the water level and radon concentration in a hot spring well of the Taodong,Yongchun County,which can be used as an important imformation ofshort-term earthquake forecast in the area.
1986年以来台湾省花莲、菲律宾(?)、福建省南日岛海域及蓬壶发生过几次地震,发震前桃东温泉井的水量、水氡含量均有明显的规律性变化,可作为短期地震预报的重要信息。