Analysis Of Geo-hazard Influencing Factors At Gansu Segment In The Bailongjiang River Basin

The formation and distribution of geo-hazard are mainly affected by geological environment and human activities. With the development of society and economy, more and more geo-hazards have relationship with the human activity. However, the impact of human activities on geo-hazard was more qualitative analysis due to its complexity and uncertainty. It has great significance to the regional disaster prevention and mitigation that quantitative analysis the impact of human activities on geo-hazard.Based on GIS, AHP (Analytic Hierarchy Process) and information entropy model, this paper quantitative assessed the quality of geological environment and the human activity intensity in the Gansu segment of the Bailongjiang River Basin. And then the influencing factor of geo-hazard was analyzed quantitatively in the study area. The main conclusions are as follows:(1) There are 2632 geo-hazards in the study area including landslides, debris flows, collapses and unstable slopes. The scale of geo-hazard is given priority to with small and medium. And it concentrated distribute in both sides of main roads and rivers in study area. The area which geo-hazard developed most has a relative advanced economy and intensive residential areas distribution.(2) The distribution area of good quality (Ⅰ), about good quality (Ⅱ), general quality (Ⅲ) and poor quality (Ⅳ) of the geological environment respectively account for 21.63%,37.66%,28.60% and 12.11% of the total study area. The distribution of the geological environmental quality is that Kang County and Tanchang County is the best, Wen County and Biebu County follows, Wudu County and Zouqu County is relative to the worst.(3) The distribution of the human activity intensity is that Wudu County, Tanchang County and Wen County is the biggest, Zhouqu County and Kang County follows, Diebu County is relative to the minimum. In the spatial distribution of human activity intensity, the bigger areas throughout the main rivers and roads on both sides, and with the increase of altitude human activity intensity gradually weakened. It is concluded that AUC (Area Under Curve) is 0.845 and the result has good effectiveness using ROC (Receiver Operating Characteristic Curve) and geo-hazard points to the results validity check.(4) In geological environmental aspects, with the increase of the elevation, the slope, the relief amplitude, the distance of the active fault, the index of NDVI and the quality of the geological environment in the study area, the density of geo-hazard is the power exponential decline. And in human activity aspects, with the increase of the residential areas density, the roads density, the population density, the economy density and the human activity intensity in the study area, the density of geo-hazard is the power exponential increase.(5) Human activity is the main factors affecting the distribution of geological hazards. And residential areas and roads are the most important factor influence on the distribution of geological hazards in the study area. The impact of residential areas and roads in the study area to geological hazards are the power exponential decline with distance. The biggest influence scope is similar to different level residential areas and positively correlated to the levels of the roads.