Evaluation Of Eco-environmental Geological Quality In Baiyu County Based On GIS Technology

Recently, a series of environmental problems, which are related to human survival closely, have been emerging. Human faces a lot of problems, such as population expansion, resource shortage, environment pollution, etc. They influence human harmonious and sustainable development. In these problems, the eco-environmental geological problems occupy prominent position. In order to solve this urgent problem, the further research of eco-environmental geological condition, the practical survey of eco-environmental geology and the reasonable evaluation of eco-environmental geology are all imperative. The scientific evaluation of eco-environmental geology is the basis of quality division and management. It could help to protect human eco-environmental geology system effectively.In this evaluation of eco-environmental geological quality, the general evaluation objective is divided into evaluation of natural eco-environmental geological quality and residential eco-environmental geological quality. On the basis of the thorough discussion of eco-environmental geological condition in Baiyu County, two sets of evaluation index system which are pertinent, leading, comprehensive and maneuverable, are constructed by GIS. Two different types of evaluation unit and the corresponding different methods of index gaining and assignment are utilized to evaluate the two decomposition objectives. The eco-environmental geological quality grade for each evaluation unit in Baiyu County is determined by the use of three evaluation models which are called principal component analysis, B-P neural network and hierarchical analysis. The three evaluation results are combined together so that the final grade belonging of each evaluation unit is obtained. The main achievements in this research are as follows:(1) The survey of eco-environmental geology in Baiyu County is introduced. The main problems of eco-environmental geology, such as soil, petrology, vegetation, geological hazard, and so on, are analized. The necessity of the evaluation of eco-environmental geological quality in the region is expounded.(2) The evaluation objective of eco-environmental geological quality is divided into evaluation of natural eco-environmental geological quality and residential eco-environmental geological quality. The respective evaluation index system is built pertinently. It provides reference for the evaluation of eco-environmental geological quality in plateau mountainous region.(3) According to the evaluation characteristics of the two decomposition objectives, the township administrative region and the administrative headquarters are consided as the basic evaluation unit. It improves the evaluation maneuverability.(4) According to the index assignment requirements of the two different types of evaluation unit, the different methods are applied in the course of index data access. In the characterization form, the similar meaning index is made a difference between the two different evaluation index systems, so that the efficiency and accuracy of index data access are improved.(5) The three sets of disparate evaluation theory of PCA model, B-P neural network model and AHP model are used to evaluate the objectives, and then the quality grade is divided. The final grade belonging of each evaluation unit is the result which is integrated with three kinds of mathematical model algorithm. Therefore, the accident of evaluation results is reduced as greatly as possible.(6) The evaluation result of the natural eco-environmental geological quality and the residential eco-environmental geological quality in Baiyu County indicates that the overall quality of the western alpine canyon area is superior to the central valley area and eastern demo shape plateau area. The evaluation results could provide scientific reference for the governance of eco-environmental geological problems and the protection of ecological environment and geological environment, and also guide the ecological, urban and rural planning and construction in Baiyu County.