Abstract: Early warning of meteorological risk associated with geological disasters is difficult and it is presently the focus of geological disaster prevention and management. The Longnan area in Gansu Province is one of the most hazardous areas in China with major casualties and property losses caused by natural disasters. This study is aimed to accurately predict the meteorological risk associated with geological disasters in Longnan. By using ArcGIS software, we divided the research area into 250 m×250 m raster and selected 9 factors to assess the areas susceptibility of geological environment by the information value method. Combining effective precipitation and susceptibility we constructed an early warning model system which was verified and tested by 6 historical rainfall events. The system has a statistical prediction accuracy of 83.42%, which is an improvement for the study area. We show that the geoenvironmental susceptibility division, based on the information value method, is objective and sensible. And a second generation early-warning system that integrates underlying surface and meteorological factors should have higher prediction accuracy and applicability in the study area.

Key words: geological disasters, meteorological risk early warning, information value, susceptibility of geological environment