Study On The Inoculation Law And The Accumulation Of The Landslide In The Chang'an District Of Xi'an

Xi’an Chang’an District has diverse topographies, like mountains, plain and loess tableland. Landslide collapse and geological disasters of north slope of Qinling mountains and the edge of the loess tableland are widespread and have, its wide bad effect on people’s life. It is one of the counties which are most dangerous area in Shaanxi province. The landslide collapse and geological disasters are serious threats to the safety of this area people’s lives and property all the same time, and these disasters affect the regions economic and social development.Chang’an District is the study area in this paper. We analyze the features and the regularity of distribution of the landslide and other geological disasters in detail in Chang’an District, combined with investigation data where collapse and landslide happens with natural geography, weather, hydrology, regional geological environmental conditions and so on that we collected. We make a research on the breeding rule of landslide collapse disasters applying Geo-Informatioin-Tupu and the CF method of Deterministic coefficient in GIS and we apply fuzzy comprehensive evaluation (FCE) to divide the places where collapse and landslide happens easily or not. Thus, we get the partition map of geological disaster susceptibility.The present condition of the collapse and landslide in Chang’an District:there are 103 zones of the collapse and landslide in total, including 67 zones of landslide, accounting for 65%. And the rest 36 zones of collapse accounting for 35%.The regularity of distribution of the areas exists collapse and landslide:duing to the variety of the landscapes and the large diversities of geomorphic conditions, the distribution of collapse and landslide is extremely uneven. Collapse and landslide and other geological disasters are easy to break out together in the south of Qinling Mountain, the east of the Loess Platform region and the flood alluvial area at the mountain front.But to the contrary, the western flat alluvial plain around Weihe river hardly develops geological disasters. As stated, we can see the areas developing collapse and landslide concentrated in Wangmang, Wangqu, Weiqu, Ziwu and other subdistrict offices.The law of collapse and landslide developing in Chang’an District:collapse and landslide mainly develop in loess and engineering geological rock groups consisted of loose clayey soil and crushed stones.Landslides develop at areas the altitude is under 1350 meters, the slopes are between 10 degree and 30 degree and the direction is towards south.Collapses develop at areas the altitude is between 450 meters and 900 meters, the slopes are between 15 degree and 30 degree. And collapse and landslide develop evidently at areas that are away from fault zone 1000 meters and away from water system 500 meters.On the foundation of the law of collapse and landslide developing in Chang’an District, we apply the theory of gray system to make sure the weight of impact factor and we also use fuzzy comprehensive evaluation (FCE) to divide whether collapse and landslide develop easy or not in Chang’an District, based on factor membership via Trapezoidal function. So we can draw a conclusion that the areas where collapse and landslide break out easily or not. the results are as follows:About six zones are high probability to happen geological disasters, including A1,A2,A3,A4,A5,A6 and three zones are middle probability, including B1,B2,B3 and one zone for low probability C and one zones hardly happening geological disaster is D.