Landslide Risk Zoning And Prediction Based On GIS

Goe-harzads(landslide,collapse,debris flow ) is one kind of natural hazards which lead to death and economical loss and casualty. Many research focused on single hazard, mostly landslide. The research of regional distribution proceeds quite slowly. It is essential for goe-hazards prevention to carry out the research into regional goe-hazards risk evaluation, and to establish a scientific, complete and practical evaluation method of regional goe-hazards risk zonation.Longsheng county of Guangxi Zhuang minority region is chosen as the research target in the paper. Based on the rich practical data, this paper makes the in-depth research into various factors affecting the occurrence of goe-hazards, conducts an overall analysis on the relationship between the time-space distribution of goe-hazards and all factors, and explores the method of evaluation of regional goe-hazards. It preliminary establishes the system of risk evaluation of regional goe-hazards. The key researches, approaches and conclusions are as follows:The paper proposes the CF logic regression model to address the consolidation of different data layers during the Goe-harzads critical evaluation through GIS-based statistical analysis model and the determination of data layer superposition weight. By combining the certainty coefficient (CF) and logic regression model (Binary Logistic) and with the assistance of SPSS statistical analysis software, the factor selection, heterogeneity data consolidation and the data layer superposition weight are solved and the precision and efficiency of goe-hazards susceptitvty zoning are improved.Sensitivity analysis on the landslide impact factor in the research area is carried out by using the goe-hazards certainty coefficient; Key factors affecting the goe-hazards in the research area are determined by the consolidated inspection on the certainty coefficient. Logic statistical analysis predictive model is established, and through homogeneous meshing, the space quantitative evaluation on goe-hazards susceptivity is realized.Research shows that goe-hazards is mostly likely to happen at the slope of 20°～40°and northwest, south and west , as well as elevation between 320～800 m. Key factors affecting the goe-hazards risk include the aspect of slope, elevation, petrofabric, inclination and road construction.Based on the calculated cell goe-hazards probability of occurrence, the goe-hazards risk in Longsheng County is divided into 4 grades, namely extremely unstable, unstable, basically stable and stable.Inspection is carried out on the new landslide sites of longsheng .The result shows that in the extremely unstable area and unstable area, the density of goe-hazards quantity is 0.0395 per km2 and 0.0251 per km2 , more highly than the stable area. So the evaluation result is in reasonable agreement with the actual landslide.