The Establishment And Application Of Leshan City's Urban Geo-Environmental Database

With the development of the urbanization of construction and economy, the influence and pressure of city geological environment have increased steadily, which constrain the urban development as well as affect people's normal life .In order to solve the geological problems and disasters around city, people all over the world has began working on it for many years, and the enhancement should be implemented in our country imperatively as well.Leshan city, located in the southwest of Sichuan province, belongs to coteau and highland area. Recently, with the fast process of urbanization, lots of environmental geological problems have strongly restricted the further development of city, such as landslide, landslip, pollution of water and soil. Therefore, it is very necessary to get down to the research on city environmental and geological problems.The paper documents and manual management are difficult to satisfy the demand of regional survey development due to the complex and abundant environmental geologic space and non-space information in city, which make it is urgent to find more effective management and analysis method. MAPGIS is powerful to manage the space information which makes it suitable for regional study. In this paper, Geo-environmental database has been established using MAPGIS in Leshan city for 2020 planning, and the environmental geology evaluation has also been done.In this paper, based on the investigation and previous work of geological information in the study area, the main environmental geological problems in Leshan city have been determined. According to the analysis, among the various drivers of environment geological quality, the terrain slope, rock properties, groundwater resource, geological hazard, foundation stability and water environment pollution are chosen as the evaluation factors, and corresponding weight are determined through the fuzzy comprehensive evaluation method. And then the Geo-environmental database is established as well as maps generation. Using the function of spatial analysis and the input-output of MAPIGS, the indexes of evaluation factor are extracted automatically and exported as the data source of fuzzy comprehensive evaluation model. Through the fuzzy comprehensive evaluation model, the unit hierarchical of environment geological quality is calculated, and the final results of the environment geological quality partition are produced.Besides all mentioned above, the 3d geological model for geologic study in the use of GOCAD is built for Leshan city which makes its geological structure more intuitionist. This work also makes up the weaknesses of MAPGIS system in the aspect of 3d model.