Research on the eco-geological environment carrying capacity in pingwu county after the wenchuan earthquake based on the modified AHP

Abstract

Many counties in southwestern China were devastated by the Wenchuan earthquake, and this earthquake also induced several geological hazards. Therefore, evaluation of the eco-geological environment in the disaster area is essential for county restoration and ecological remediation. This research considers Pingwu County, which is located 89 km from the epicenter of the Wenchuan earthquake, as the study area to evaluate the eco-geological environment carrying capacity. First, three evaluation index layers are built for an eco-geological environment carrying capacity model after the earthquake, including the geological, ecological and social environments. Then, the evolutionary algorithm is used to modify the analytic hierarchy process (AHP). By optimizing the consistency ratio of the AHP, the most consistent evaluation matrix can be obtained. Finally, we calculate the eco-geological environment carrying capacity in Pingwu via the best consistent evaluation matrix and obtain a hierarchical map of the eco-geological environment carrying capacity through grid rasterization. The results indicate that the current eco-geological environment carrying capacity in Pingwu County mainly contains two states, equilibrium and surplus states. According to the hierarchical map, this study suggests that focusing on ecological protection and disaster monitoring in the eastern and northern areas of Pingwu, large infrastructures should be built in the central and southern areas, and the land use capability should be further improved. Moreover, construction in the central area of Pingwu should be optimized, the scale of regional construction should be controlled, and the original ecological species in the natural protection area should be maintained.