Gis System Of Quality Assessment Of The Regional Geological Environment

As the overall development of geological hazard survey and zoning in the national counties and cities, which started by Ministry of Land and Resource, how to judge the degree of good and badness of geo-environment quality according to a great quantity of investigating information becomes more and more important. Because of powerful data tackling ability and spatial analysis function, Geographic Information System (GIS) provides a new study method for regional geo-environment research.The thesis has analyzed main control factors influencing regional geo-environment synthetically. On the basis of summarizing predecessors' experience, the thesis has determined geo-environment quality assessment index system and established classifying standard, which aiming at the characteristic of geo-environment quality. Vector principal component analysis and paired-comparisons method have been adopted to sift and optimize assessment indexes. Hierarchy analytic process has been applied to find the weight of assessment indexes. According to the characteristic of assessment model, the thesis has adopted mainly expertise to quantify qualitative indexes, while quantitative indexes get their value through fuzzy membership function on the basis of classifying standard. According to the characteristic of regional geo-environment quality assessment, the thesis has chosen two kinds of simple and practical mathematical methods, fuzzy comprehensive assessment and information method to establish assessment models, and then the two assessment results have also been compared. The analysis module is developed with C++Builder6.0 software. Based on the development platform of MAPGIS6.5, 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.Taking Hancheng City of Shaanxi province as example, the thesis has analyzed its geology environment background, chosen the main factors influencing geo-environment quality, and established the spatial graph database and property database of Hancheng City. Based on this system, the geo-environment quality of Hancheng City has been assessed, and the results show that the geo-environment quality can be classified into four classes: best, good, moderate, worst. So, it further indicates that the system is feasible and very practical and that the assessment models are rational.