Analysis Of Relationship Of Topography And Topographic Evolution With Landslides Based On GIS

ABSTRACT:China is one of the countries that suffer landslides mostly, especially in southwestern China. Based on the973project, and taking the Lushan earthquake region as the study area, the control action of topography and geology on landslide was analyzed by summarizing relevant information home and abroad, then1215landslides were obtained by the interpretation of Lushan earthquake-triggered landslide on GIS, finally a landslide group and geological information database were established besides a3-D geological analysis model through on-the-spot investigation on the lithology, hydrometeorology and topography of the study area, meanwhile through the application of GIS, quantitative description of the influence mechanism of topography on landslide was carried out and the elevation of landslide was explored, also the relationship between landslides and terrain and its evolution was revealed. The main research contents of this paper are as follows:(1) According to relevant information, a3-D geological analysis model was set up, then the spatial analysis and interpretation of Lushan earthquake-triggered landslide were carried out, finally,1215landslides were obtained. Also, a landslide group and geological information database were established.(2) Based on the3-D geological analysis model and database, the terrain parameters of Lushan region was analyzed, and relationships between landslide parameters and terrain feature parameters was established. The topography conditions dominate the occurrence of landslides:elevation of0.9to1.3km is the sensitive areas of landslide development; terrain slope of30°is the "threshold" for landslide occurrence, and the probability density of landslide is a normal distribution whose mean is30°; there are close relationships between landslides and faults and rivers, the closer to the faults and rivers, the more easily landslides occur.(3) Statistical analysis on the major terrain parameters--elevation, slope and distance from faults and rivers--that affect the occurrence of landslides was carried out through Matlab. The probability density of landslide distribution under the four factors was calculated respectively, and the landslide impact model for the four factors was set up through the function fitting of the probability density.(4) Take the valley landforms of Ling Guan River in Lushan as an example, according to historical data and topographic and geological characteristics of the region, the elevation law of terrain was explored, then the simulation of evolution of landslides and terrain was carried out, finally the sliding mechanism of landslides of Lushan region was analyzed. The general rule of evolution of geomorphology and landslides in Lushan was revealed.