Hazard Assessment Of Geological Disasters In Taibai County, Shaanxi Province

As a disaster-prone country, China is facing serious threats on human life and property. With the development of west regions and rapid constructions of mountain road, the geological disasters emerged in central and western mountains have a character of intensive and massive, especially in the flood season. Compares to the experience of western countries in risk management, the work in China has just started, and there is not an uniform technical standards until now. In this paper, by introducing the international landslide risk management method, the hazard assessment of geological disasters in Taibai county is carried out on the basis of research work already done. The specific contents are as follows:â‘ The feature analysis of geological disaster in Taibai county. On the basis of the datailed investigation, we conclude that the main types of geological disasters in study area are landslide, collapse and debris flow, and by generalizing the investigation data, a significant spatial and temporal distribution was found in this area. The formation of disaster is influenced by internal and external dynamic and a potential hazard is obviously existed.â‘¡The geohazard susceptibility of Taibai county. Topography, lithology and structure, human engineering activities are selected as the three calculation indicators of the regionalization, which are further divided into eight elements, are given weights by means of AHP. In the same time, the information values of different elements are obtained by the information method in ArcGIS platform. By combining the weights and the values, the study area can be divided into high-prone, middle-prone and low-prone regions, and the geohazard susceptibility map could be generated at last. The evaluation showed: the high-prone region of geological disaster in Taibai county is mainly distributed along the highroad and valley, which account for 7.9% of the whole area and where the human engineering activities are strong, the probability of geological hazards is significant. The middle-prone region accounts for 45.3% of the area, and the probability of disasters is comparatively large. The low-prone region accounts for 46.8% of the area, it is less prone to suffer geological hazards.â‘¢The hazard assessment of Taibai county. On the basis of the study of geohazard susceptibility, further considering the inducing factors of geological disasters and form the hazard assessment model. The hazard assessment of Taibai county is achieve in the ArcGIS platform, and the area is divided into three regions of high-risk, middle-risk and low-risk. The evaluation showed that the high-risk region of geological disaster in Taibai county is mainly distributed along the highroad and valley, which account for 6.8% of the whole area and where the human engineering activities are strong, the vegetation cover is relatively low. The reconstruction of the environment is strong, and the average annual rainfall distribution is high. In this region, geological disasters are especially prone to generate in rainy season, and the road and the safety of pedestrian are threatened seriously. The middle-risk region is covered for 50.0% of the area, which is the main distribution area of popolation and has a comparative high annual rainfall, is prone to generate geological disasters. The low-risk region accounts for 43.2% of the area, where the population density is low and the average annual rainfall is only 500-600mm, the geological disasters are relatively less prone to generate.