Evaluation Of Geological Hazards In Luohe River Basin In Loess Plateau

Luohe River which is in the middle part of Loess Plateau has representative characters of Loess Plateau. Human engineering activities and natural factors including rainfall and river erosion triggered the main geology hazard in it is landslide.In this paper, by taking the whole Luohe River region as the research object, build a database by the GIS platform to collate the existing geological disasters data. Using the MapGIS to edit functional data and ArcGIS to analyze data, summarize the development types and regularities of distribution of geological disasters throughout the whole study area. And the establishment of evaluation model by the method of weighted information to evaluate the extent of the geological disaster-prone areas. The main work of this paper is as follows:(1) By collating the existing geological disasters data and using MapGIS, draw a geological map, topography map of loess plateau (1:1000000). Intercepting the part of the Luohe River from the maps is as the maps of the basis geological datas.(2) According to the existing geological data, combined with the actual situation in the field survey, the statistical data of developed geologic disasters in the study area is about 2886, and the landslide is serious, accounting for 82% in the statistical data of the total geological disasters, followed by collapse and unstable slopes, which together account for 17% in the total statistical data, and account for 1% of in the total statistical data are other geological disasters. The information of raster database which is analyzed by ArcGIS provides a wealth of basic data for the evaluation of regional geological hazards.(3)According to the statistics information of geological disaster through GIS, founded that the composition of the majority of the landslide and other geological disasters is soil, mostly medium-sized. They mainly developed in the loess liang, mao and yuan with valleys and gullies around the middle part of the luohe River and on the both sides of its tributaries. At the same time, the landslides, avalanches and other geological disaster is triggered by rainfall, and resident engineer activities.(4) 8 evaluation factors selected is as the susceptibility evaluation indicators: disaster point density, slope, slope type, formation lithology, rivers, vegetation, rainfall and resident activity. They are weighted by AHP, and their information is statistics by the information model. And then according to their weight and information, the geological disaster-prone areas zoning map of Luohe basin was drown. Statistical analysis shows that high-prone area accounted for about 43% of the total area, which is mainly distributed in the region which Luohe River flows through. The middle prone areas accounted for 30% of the total area, mainly distributed in the region which the level tributaries of the Luohe River. The low-prone areas accounted for 26%, mainly in Luohe source or a two, and other tributaries of the region.The research result can provide a reference for the prevention and control of geological disasters and economic layout in the Luohe River basin.