Evaluation of Post-Earthquake Geological Environment Carrying Capacity Based on AHP-GIS Coupled Analysis Method

Abstract

Pingwu County, located in the north of Sichuan Province, China, was severely affected by the Wenchuan Earthquake in 2008. The county is part of the Fujiang river basin, and a large number of earthquake-induced geological hazards have developed in the area since the earthquake. Post-earthquake reconstruction in key towns and regional development is important and requires a scientific evaluation of the geological environment’s carrying capacity. In this study, geographic information system (GIS) - analytic hierarchy process (AHP) coupled analysis method is used to combine the post-earthquake geological environment background, disaster point distribution, and social development in the area to construct an evaluation system of geological environment carrying capacity based on ten evaluation indicator layers of geological environment, ecological environment and social environment. The weight of each evaluation indicator is calculated using the AHP analysis method, and the carrying capacity of the geological environment in Pingwu County for each GIS grid is calculated, thereby obtaining a division map for carrying capacity. The results of the evaluation show that the geological environment carrying capacity of the Pingwu County is balanced (critical overload) and surplus (not overloaded). Further, no overload condition is present, and the distribution of loading is related to human construction. In general, the carrying capacity of an area is low in areas with a high degree of construction and other related activities. Based on the evaluation results of the carrying capacity of the geological environment, this study provides suggestions for optimizing the construction of the central area of Pingwu County, controlling the scale of regional construction, maintaining the original nature of ecological species in the natural reserve area and prohibiting development and transformation, and providing a clear direction of development for the post-earthquake development planning of this area.