| The 5.12 Wenchuan earthquake happened in eastern middle and high mountain areas of the West Sichuan Plateau. Because the geological environment is fragile, The Earth crust is fractured,the mountain massif is broken. A number of Collapses, landslides and mud-rock flows etc geologic disaster are caused by the earthquake. They are widely distributed, the type is complicated, often causes catastrophes. After the earthquake, the outbreaks of the debris flow in the study area have characteristics of high frequency, large scale and serious potential hazards, which become big obstacles to reconstruction. Against this background, the interpretation of potential debris flow is significant for the reconstruction after earthquake. After the earthquake happened, all satellite remote sensing companies rapidly organized to acquire remote sensing data of disaster areas for disaster relief and provided the first hand of remote sensing images. A number of scientific research institutions and universities and colleges joined in remote sensing investigation and emergency assessment. Viewing the extraction method of the geologic disasters, although making great progress and the precision is increasing ,but which are not suitable for the information extraction of the sudden potential flow that are rarely seen in articles.The paper is based on The Prevention of Geological Disasters and Geological Environment Protection State Key Laboratory "technology relief and rebuild homes" special research fund project "wenchuan earthquake induced slope geological hazards with reference to the remote sensing image interpretation and assessment" and the independent research fund project of State Key Laboratory "the hidden trouble of potential mudslides recognition standard and prediction appraisal method study in the Wenchuan quake areas". Select the area From Yingxiu to Laohuzui which is hit more serious in the earthquake as a study area to high spatial resolution images of the data source, high spatial resolution images as data source. Interpreting and extracting information geologic disasters (Collapses, landslides and mud-rock flows) of study area on the basis of three-dimensional virtual scene using GIS, RS and GPS techniques and human-computer interaction. Interpreting the potential debris flows in the study area on the basis of evaluating and analyzing the active flows. The main results achieved in the paper are shown as following:(1)Building remote sensing images geological interpretation three-dimensional visualization image dynamic analysis picture of study area using images after earthquake and DEM extracted by the images: Combining technology of three-dimensional visualization with remote sensing technology to build three-dimensional remote sensing images dynamic analysis picture of study area, which not only can directly and vividly show the characters of geologic disasters,and still can dynamically observe geological hazards in more perspective and multi-scale, Providing guidance for the two-dimensional image interpretation of geological disasters and field investigation, providing reference for later prevention and repairmen.(2)The interpretation of landslide, collapse and active debris flow: according to established interpreting marks and existing geological, geographical and other related information, combing with the analysis and interpretation of development geological disasters' background and disasters body information, using remote sensing images and three-dimensional model combining field survey, landslide, interpreting and extracting information of collapse, landslide and debris making use of man-machine interactive, determining the types, position and boundary of the geological disasters.(3) The analysis of mudslides impact factor and danger zones classification: With active debris flow gully as sample, referring to the research achievements of predecessors and mud-rock flow distribution, select six relatively stable factors, namely elevation, slope, fracture, land use type and density of landslides, collapse and the day biggest rainfall of the year to analyzed development characteristic of the debris flow gully of study area, and the research area mudslides risk zoning is gained, which is divide into three-level, namely the high-risk areas of mudslides, the middle-risk areas of mudslides and low-risk areas of mudslides.(4) The interpretation of potential mudslides: on the basis of geology, topography, meteorology and water resources etc geological hazards development environmental factors, With the average of active debris flow gully risk as a standard to judge the undetermined gullies. Judging the potential mudslides with three-dimensional visualization technology assistance and in a way of the man-machine interactive to determine the possibility whether landslides will happened.This paper based on post-earthquake remote sensing image interpretation and field investigation data, using the GIS, RS and GPS techniques to interpret mainly as potential debris flows hazards geological disasters in the study area,providing references for disaster prevention and mitigation of potential mudslides and recovery plan of post-seismic. |
PDF Full Text Request