我国土壤侵蚀与地理环境的关系

A STUDY OF THE RELATIONS BETWEEN SOIL EROSION AND GEOGRAPHICAL ENVIRONMENT IN CHINA

本文论述我国土壤侵蚀类型与自然地带性和非地带性因素的关系,分析影响侵蚀强度时空分布和侵蚀泥沙输移的环境因素及流域条件。

With a mean annual soil erosion amount of 50 × 108 t and a variety of soil erosion types and patterns, China is one of the countries with the most serious soil erosion in the world. The spatial distribution of soil erosion types is controlled by both zonal factors (including horizontal and vertical zonal factors) and azonal factors. The macro spatial areal differentiation of soil erosion intensity in China is found to be dependent on naturel factors such as precipitation, vegetation, topography, surface materials and geological structures, while the temporal variation in soil erosion intensity is dependent on human activities. In China almost all the areas with the highest soil erosion intensity are located in semi-arid zones. This study indicates that the transport amount and distance of the eroded materials have nothing to do with drainage basin area, but they are in close relation with the geographical environmental factors in the drainage basin such as the geological structures, neotectonic movement features, landforms, surface materials, runoff conditions and the economic development.The study also indicates that the erosion-protection strategy which is made on the basis of geographical conditions related to sediment delivery process and areal differentiation of erosion types and intensity will greatly promote the development of water and soil conservation and the improvment of ecological environment.