| The reach area of Jing River Basin located in the middle of Longdong Loess Plateu.Under the inducing of some natural factors such as rainfall,river erosion and human engineering activities,consisting mainly of geological disasters landslides widely developed.In this paper,we chose the whole Jing River Basin as the research area,and establish the data base rely on the GIS platform, synthesize the data from geological survey which we have already known.and use the function of mapping data from MapGIS and the function of analyzing data from ArcGIS,we summarize development type and regularities of distribution of geological disaster in the whole researcher area. And establishing the evaluation model by the method of weighted information to evaluate the extent of the geological disaster-prone areas. The main work of this paper is as follows:(1) By collating the existing geological disasters data and using MapGIS, draw a geological map, topography map of loess plateau(1:1000000). Intercepting the part of the Jing River from the maps is as the maps of the basis geological datas.(2) synthesizing the data from geological survey, the statistical data of developed geologic disasters in the research area is 2536, and the landslide is the most serious, accounting for 66% in the statistical data of the total geological disasters, followed by collapse, which together account for 21% in the total statistical data, and account for 13% of in the total statistical data are debris flow. The information of raster database provides a wealth of basic data for the evaluation of regional geological hazards.(3)According to the statistics information of geological disaster through GIS, founded that the composition of the majority of the landslide and other geological disasters is soil, mostly medium-sized. Which is mainly developed in the area of Liupan mountain which is the head of Jing river and Longdong loess plateau in the middle of Jing river. The disaster of the research area is mainly influenced by the river. At the same time, the landslides, avalanches and other geological disaster is triggered by rainfall, and resident engineer activities.(4) 7 evaluation factors selected is as the susceptibility evaluation indicators: slope, slope type, formation lithology, rivers, vegetation, rainfall and resident activity. They are weighted by AHP, and their information is statistics by the information model. And then according to their weight and information, the geological disaster-prone areas zoning map of Jing river basin was drown. Statistical analysis shows that high-prone area accounted for about 46% of the total area, which is mainly distributed in the head of Jing river and the drainage line of Jing river upstream and Malian river upstream which is the biggest tributary of Jing river.The middle prone areas accounted for 30% of the total area, mainly distributed in the region which the big tributaries of the Jing River fiow through. The low-prone areas accounted for 24%, mainly in the north of Jing river which has less tributaries and Guanzhong plain in the downstream of Jing river. |
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