Study On The Fractal Dimension Of Spatial Distribution Of Geological Disasters In Chongqing Based On Gis

Combined effect of unique geology, topography, climate and hydrological conditions making Chongqing become China’s geological disaster-prone areas. And with the accelerating urbanization, the number of geological disasters that human-induced gradually increasing in Chongqing. Throughout the course of social and economic development of Chongqing, as a whole, disaster that as a negative economic, plays a negative role on the social economic development of Chongqing. Thus, strengthening research of geological disasters, especially the spatial distribution of geological disasters, has practical significance.Based on1:500,000geological disaster-prone Zoning Picture, thesis analyze the causes and spatial distribution of geological disasters in Chongqing. The main factors affecting the formation of geological disasters in Chongqing are geological factors, landforms factors, heavy rain factors and human factors, and the spatial distribution of geological disasters are mainly affected by lithology, geological structure and topography. In addition, the spatial distribution of geological disasters in Chongqing also has the obvious characteristics of the strip that centralized distribution along the river and transit.Based on fractal dimension theory and using the grid method, thesis analysis the fractal characteristics of the spatial distribution of geological disasters in Chongqing and calculate its fractal dimension from the perspective of different studies. First, thesis analyze the space fractal characteristics of geological disasters in Chongqing and its main counties and the geological disasters spatial distribution of the main counties has significant fractal nature and the no-scale interval is mainly concentrated in the2-8km.Fractal dimension of the spatial distribution of geological disasters in the counties are large different and the maximum is1.3621(Yunyang County), the minimum is0.2813(Dazu area). Fractal dimension of the spatial distribution of geological disasters along the Yangtze River that Fengjie to Fuling is large and this is a prone areas of geological disasters in Chongqing. Fractal dimension of the spatial distribution of geological disasters in west area of Huaying Mountain is small and has less geological disasters in Chongqing. Second, fractal dimension of the spatial distribution of geological disasters in different rock group has significant fractal nature and fractal dimension of the spatial distribution of geological disasters in different rock group are large different. Fractal dimension of the spatial distribution of geological disasters in sand and mudstone rock group is maximum(1.4382) and this is a major geological disaster-prone stratigraphic in Chongqing. Third, the spatial distribution of geological disasters in Chongqing has obvious height differentiation. The density and the number of geological disasters at an altitude of200-1000m is the largest and the fractal dimension value of the spatial distribution of geological disasters is also the largest. Based on cutting depth analysis, the number of geological disasters, density and the dimension value of the spatial distribution of geological disasters is the largest in the cutting depth50-800m area.The degree of geological disasters are large different between different geomorphic types. Erosion low mountain is the geological disaster-prone areas and the value of the fractal dimension of the spatial distribution of geological disasters is maximum. Fourth, within each river’s lkm buffer zone of Chongqing, the spatial distribution of geological disasters have fractal dimension features and the no-scale interval mainly concentrated in2-10km, but the value of fractal dimension is quite different.Based on analysis of fractal dimension of the spatial distribution of geological disasters in Chongqing, thesis further explore the factors that influence fractal dimension values of spatial distribution of geological disasters in Chongqing. First, the value between fractal dimension of spatial distribution of geological disasters that along the river and transit and fractal dimension of river and transit has some relevance, namely, the erosion of river and construction of transit are induced factors of geological disasters in Chongqing. Second, the value of the fractal dimension of spatial distribution of geological disasters and the number of geological disasters in the study area are highly and universal correlated. The value of the fractal dimension of spatial distribution of geological disasters and density of geological disasters in the study area has some relevance. Third, the value of fractal dimension of the spatial distribution of geological disasters is related to its spatial pattern types, The pattern of spatial distribution of geological disasters in Chongqing is given priority to aggregate type distribution, the second is random distribution and random aggregate type distribution. The value of fractal dimension of aggregate type distribution＞the value of fractal dimension of random aggregate type distribution＞the value of fractal dimension of random type distribution.