A Sampled Method of Classification of Susceptibility Evaluation Unit for Geological Hazards based on GIS

In order to enhance evaluation precision for the susceptibility of regional geological hazard, this paper proposes a new method by which a large-scale study area can be automatically divided into minimum suitable evaluation units with taking slope unit as an object of study using geographical information system (GIS) and hydrological analysis tools. Based on this new method, Huangling County in Shaanxi Province has been classified into 6258 minimum suitable evaluation units, with a model for score of contribution to geological hazard susceptibility, the distribution of susceptibility score for each evaluation unit could be calculated, and then the susceptibility of regional geological hazard in Huangling County could be evaluated by each region accordingly. Evaluation results are as follows: 5 regions with different level of geological hazard susceptibility are divided in the area of Huangling County according to susceptibility score, among of them, regions with High Susceptibility account for 9.94% of total area in whole county, mainly situated in Luo River, Ju River and KouJia River Valley which are the key areas for prevention and cure of geological disaster in the future. The Sampled method can be extended to division of geological hazard susceptibility of other similar areas.