The Study Of Geological Disaster Susceptible Division In Leiyang Based On ArcGIS

Leiyang, tectonically belongs to southern of Hengyang Basin, is located in the southeast of Hunan province. It possesses rich mineral resources and is one of the top 100 counties rich in coal resources in China. With the rapid development of national economic and long-term mining activities, the geological disasters frequently take place, which do serious harms to people and property, and hamper the sustainable development of society. Based on the detailed survey of geological disasters in Leiyang, the geological hazard susceptible evaluation was carried out. The study results have stimulative effect on geological disaster susceptibility evaluation method at hilly region, south China, and have the guiding significance to the geological disaster prevention and disaster reduction in Leiyang.On the basis of field inspection, detailed statistic and analysis of geology datum, the main types, scales and the development features of geological disasters in Leiyang are summed up. The research shows that the main types of the geological disaster are unstable slope, landslide, collapse and surface collapse. The geological disasters are given priority to small scale with frequency of occurrence. The distribution and density of geological disasters have close relation with the geological background such as stratum and lithology, topographty, geological structure, rock mass structure, rainfall, and human engineering activities.Based on the analysis of influence factors as well as the local condition in Leiyang, density of disaster, slope gradient, density of gully, rock structure, vegetation index, geological structure, precipitation index and human engineering activity, were selected as evalution indexes of geological hazards evaluation system. Using analysis hierarchy process, the selected evalution factors were quantified. Finally, based on spatial overlay and statistical functions of ArcGIS system, the geological disasters susceptible evaluation and regionalization in Leiyang are made. The evaluation result shows that, 2 high-prone, 5 middle-prone and 2 low-prone areas are regionalized in Leiyang. The high-prone area is about 708 km2, accounted for 26.7% of all regions. The middle-prone area is about 934 km2, accounted for 35.2% of all regions. The low-prone area is about 1014 km2, accounted for whole area 38.1%.