Gis In The Middle Reaches Of The Yellow River The Geotechnical Erosion Geological Environment Quality Evaluation

The Yellow River is the second longest river and the mother river in our nation, the Yellow River Basin was the birthplace of China's ancient culture which was once the center of politics, economy culture of China. It is the famous silty river in the world, the bad erosion by wind and rain of the middle reaches led to much silt slipping into the Yellow River especially in recent years, the soil erosion was serious with each passing day, the desolatnisation and salinification of soil is constantly expanded, couapse, landslide and mud-rock flow occurred there frequently, and also surface subsidence, ground cleaves and ground couapses occurred. In accordance with gedogy environmental problems, the departments of water, water protection, farming and forestry have done much work since the Founding of our People's Republic. Owing to the restriction on work aim, scope, precision and technique, lacking of the investigation and analysis, works can not put forward the suitable advices systematically from various angles to prevent and cure the soil erosion. According to geo-environment characteristic, summing up predecessor's experience, the paper has set up geo-environment quality assessment index system and established classifying standard of index. After that, the paper analyzes systematically quantifying method of index, sifting methods of index—comparing one with one method and conditional broad least variance method, and weighting method of index—analytic hierarchy weighting process. The theory of multi-classification fuzzy pattern recognition model is introduced comprehensively, which is based on the relative membership degree and function. The analysis module of multi-classification fuzzy pattern recognition model is developed with C++Builder6.0 software, for the purpose of geo-environment quality assessment. Based on the development platform of MAPGIS6.1, the spatial graph database is established. By linking outside database, the property database is performed. Then GIS transfers the property database with interface, so as to achieve link between graph and property, thus forming spatial database. By middle data documents, the integration is accomplished between the assessment analysis module and GIS, thereby achieving transferring data of both sides and carrying on spatial analysis.This paper based on GIS powerful function on data processing and space analyzing choose the mainly factor which influence the He Long section the middle reaches of Yellow River (Shan Xi and Nei Meng Gu ) to built up its space graph bankand attribute bank, they also analyse and evaluate the environmental quality of corroded rock by using this system, it was cut into four ranks: weak, strong, stronger, the strongest and at the same time they examine the special section in small valley. The result shows that the system is feasible and practical, it affords us a new study method for the evaluation of rock erosion the geo-environment quality assessment.