GIS支持下的土壤侵蚀动态变化研究:浙江一例

土壤侵蚀是土地退化的主要原因，也是导致生态环境恶化的重要因素，开展土壤侵蚀动态模拟研究具有重要意义．地理信息系统(GIS)因其强大的空间分析功能，为土壤侵蚀动态分析研究提供了有力支持．根据美国通用水土流失方(USLE)，以GIS软件为支持，以浙江省横溪流域为例，对该流域1990年至2003年土壤侵蚀动态变化进行模拟，并对流域内不同土地利用方式下的土壤侵蚀进行了动态评估，探讨了土壤侵蚀变化与土地利用变化的关系，为横溪流域今后的土壤侵蚀动态预测提供参考．

Dynamical Changes of Soil Erosion Based on Geographical Information System: An Example from Zhejiang, SE China

Soil erosion is a main factor to the soil and environmental deterioration and thus the dynamic study of soil erosion is of great importance. There are many factors can affect the soil erosion including the natural and human factors. In a general way, climate, soil, geology, landform and natural vegetation are the natural factors that can leads to soil erosion and the human factors are mainly due to the improper use of the soil, such as over-depasture and over-farming. The universal soil loss equation (USLE) is an empirical model for predicting the average annual soil loss. It predicts soil loss for a given site as a product of six major factors, whose values at a particular location can be expressed numerically. Based on the spatial analysis, Geographic Information System (GIS) gives strong support for the dynamic study of soil erosion. In this paper, we used USLE and GIS technique to simulate the change of soil erosion from 1993 to 2003 in Hengxi watershed in Zhejiang province and then to predict the soil erosion under the different land use. Our results showed that the amount of soil erosion in 2003 decreased remarkably than in 1990 and the erosion area, according to the soil erosion classification, also changed apparently. This study offered the reference for the further researches on the dynamic of soil erosion in Hengxi and other watersheds.