Evaluation of soil erosion vulnerability in the Zhuxi watershed, Fujian Province, China

Abstract

Soil erosion by water is a serious environmental problem in southern China, particularly in the Zhuxi watershed in Changting County of the Fujian Province, which is characterized by highly erosive rainfall, severely undulating terrain, porous soil, scarce vegetation, and excessive human activity. The evaluation of soil erosion vulnerability is important for soil resources and sustainable development. Using the Zhuxi watershed as an example of soil erosion problems, this study uses the analytic hierarchy process to evaluate soil erosion vulnerability in a coupled human and natural system to determine the proportions of factors in an index system based on the experience of experts. Using GIS, we confirmed that the factors in the utilized index system were exposure, sensitivity, and adaptive capacity to soil erosion. All of these factors were combined to determine the soil erosion vulnerability. The results indicated severe soil erosion vulnerability over large areas. The areas vulnerable to soil erosion accounted for 57.98 % of the watershed; and the areas damaged to a high or very high extent account for over 12.08 % of the watershed. The results also show that the soil erosion vulnerability varies in different locations. For example, soil erosion vulnerability is lower in the eastern part of the study area and higher in the western part. Therefore, an effective approach to reduce soil erosion vulnerability would be to implement measures for regional soil and water conservation and sustainable development.