Research on Eco-geological Environment Carrying Capacity for Pingwu County after Wenchuan Earthquake Based on Modified AHP

Abstract Many counties in southwestern China are devastated by the Wenchuan earthquake, and the earthquake also induced lots of geological hazards. So evaluation of the eco-geological environment in the disaster area is essential for county restoration and ecological remediation. This research accounts for Pingwu County, which is 89 km to the epicenter of the Wenchuan earthquake, as a study area to evaluate eco-geological environment carrying capacity. Firstly, three evaluation index layers are built to the eco-geological environment carrying capacity model after the earthquake, including geological environment, ecological environment, and social environment. And then, the evolutionary algorithm(EA) is used to modify Analytic Hierarchy Process(AHP). Through optimizing consistency ratio of AHP, the best consistent evaluation matrix can be obtained. Finally, We calculate the eco-geological environment carrying capacity of Pingwu by the best consistent evaluation matrix, and obtain hierarchical map of the eco-geological environment carrying capacity through grid rasterization. The results show that current eco-geological environment carrying capacity in Pingwu county mainly contains two states, equilibrium and surplus. According to the hierarchical map, this study suggests optimizing the construction of the central area in Pingwu, controlling the scale of regional construction, and maintaining the original ecological species in the natural protection area.