1. Sanming Meteorological office, Sanming 365000, Fujian, China; 2. Nanping Meteorological Office of Fujian Province, Nanping 353000, Fujian, China; 3. Fujian Institute of Meteorological Sciences, Fuzhou 350001, China

Geological hazards often occur in northern Fujian. Analying the relationship between geological hazards and precipitation in northern Fujian, the authors establish the relational model ( available precipitation) of the geological hazards, and earlywarning system with GIS has been developed. Analysis result shows that the emergence of geological hazards in northern Fujian are relate with the precipitation in near 10 days, and the closest relationship is intraday heavy rain and the precipitation in near 3 days. Clustering geological hazards are mostly occurred when the precipitation in near 3 days ≥180 mm, or the precipitation in near 3 days ≥100 mm and there are continuity heavy rains in mid 4 days (or far 3 days). The precipitation ( available precipitation) presents exponential relationship with the geological hazards, and the available precipitation of geological hazards occuring in northern Fujian are: 60 mm in the middle and south parts of the highest easily occuring regions, 75��80 mm in the middle and north parts of the moderate easily occuring regions, 100 mm in north part of the lowest easily occuring regions.