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Wuqi County, which is in the northwest of Yan’an city in Shanxi province, locates in the region of loess plateau. The ecological environment of this area is one of the most vulnerable regions in our country and the special natural geography and geological environment cause the landslide, collapse and debris flow and other geological disasters take place frequently, which seriously threats people’s lives and properties. In recent years, with the intensification of human being’s engineering activities, the geological disasters present an aggravating tendency. Therefore, it has been an urgent task that brook no delay to prevent and control the geological disasters.The detailed geological disasters investigation of Wuqi County chooses the remote-sensing data of French SPOT-5 satellite, the resolution is 2.5m black- white and 10m full colors combination and the biggest image scale reaches 1: 25000. Based on these data, remote sensing interpretation of geological disaster in Wuqi County is carried out, combined with regional physical geography, geological environment and previous relevant information.First, interpretation keys of remote- sensing image and geological disasters body and points for attention in interpreting the geological disasters are introduced. Second, visual interpretation formula of remote- sensing image and basic procedures of remote- sensing interpretation and geological disasters survey are presented. Last, by use of the results of remote- sensing interpretation, taking which as guidance in ground survey of geological disaster, remote- sensing technical advantages are brought into play, thus, work efficiency and investigation accuracy are improved greatly.Geological disaster spots identified in actual ground investigation are 784 in total. among which, landslides are 721, collapses are 53, unstable slops are 9 and debris flow is 1, accounting for the total count of geological disasters in this area 92%, 6.8%, 1.1% and 0.1% respectively. Through the analysis of above data, geological disasters development characteristics and distribution law I in Wuqi County are summed up. Finally, the forming conditions of geological disasters are analyzed from the aspects of landforms and physiognomy, rock-soil body structure, water, vegetation and engineering activities of human beings.To sum up, the research of this thesis provides important basic materials and scientific basis for alleviating and controlling the geological disasters in Wuqi County . Also, it has important directive significance to find out the detail survey method and experience of geological disasters in Loess Plateau region and improve the《Detailed Investigation Code for disasters of landslide, collapse and debris flow》(1:50000).
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