A Research On Geological Disaster Risk Assessment Of Dadu River From Jiajun To Detuo

In mountain areas, landslides, avalanches, landslides and other geological disasters are common, which power has caused extensive attention. Region of interest is located in the middle part of the Dadu River which is a complex terrain, height mountains bordere on medium height mountain, valley and basin connecte. In the region of interest, the terrain is steep, the relative height is large and the faults are developed. In the structure, it is located Dadu River and Moxi fault zones. The era of exposed area is from the Proterozoic to the Quaternary. The groundwater resource is also very rich, which is mainly including loose deposits layers water and bedrock fissure water. Human activity is intense mainly including in transportation construction, water conservancy hydroelectric development and farming and so on. The complex geological environment conditions lead to geological disasters which mainly landslides, avalanches and unstable rock and debris flows.This theme study the geological hazards of Detuo-Gajun segment of Dadu River, through investigating total 57 points of geological disasters in the region of interest, including 7 landslides, 39collapse and dangerous rock body, 11 debris flows. Based on the comprehension the geological background of geological disasters, we analyze the development characteristics of geological hazards and affect factors, combined with GIS technology and the AHP model, and further analyze and evaluate geological disasters for risk in the study area, mainly get the following results:(1) The distribution of geological disasters in the study area has obvious regularity and regional concentration, distribution of geological hazards is obviously controlled by tectonic activity, with a dense distribution along the tectonic lines and densely distributed along the river.The main distribution near the fault zone and the Dadu River and its tributaries on both sides of the main types of disasters as landslides, avalanches, unstable rock and debris flow body.(2) Based on field survey of geological hazards characteristics and distribution, we further analyze the main factors, and evaluate the risk zone with selecting the 6 factors including geological structure, lithology, terrain slope, rivers distribution, height distribution and human activities, Also,through the AHP mathematical model we calculate the weight of each factor.(3) Summarize the evaluation and analysis the risk of a geological hazard method, what is Characteristics of geological hazards analysis-control factors-the weight control factor analysis-GIS overlay analysis- a comprehensive evaluation. We get a good interpretation to the process by taking advantage of ARCGIS, and get the result figures ultimately.(4) In the GIS software platform, we divided the study area into three grades hazard zones: high-risk zones (28.03%), moderate-risk zones (39.13%), low-risk zones (32.83%). Comparative analysis shows that the results of hazard zones division accord with the development status of the existing points of geological disasters.