土壤侵蚀普查对于土地资源保护和自然灾害防治具有重要意义.为了测试抽样方法和土壤侵蚀模型在土壤侵蚀普查中的适用性,该文以陕西吴起县为试点,采用1％均匀抽样方法,调查39个抽样单元的土壤侵蚀影响因子,使用中国侵蚀预报模型CSLE (Chinese soil loss equation)估算土壤侵蚀模数,并与基于遥感数据的水蚀分级分类方法进行比较.两种方法估算的全县平均土壤侵蚀模数分别为4571和5504 t/(km2·a),但不同分级侵蚀强度的面积和空间分布存在较大差异.抽样方法在土地利用与覆盖、水土保持措施及土壤特性方面获得的信息量大于遥感方法,同时对于区域具有很好的代表性;使用模型估算土壤侵蚀考虑的影响因子与分级方法相比,还包括了土壤可蚀性、坡长因子以及水土保持措施因子等,由此计算的土壤侵蚀模数和强度具有更高的可信度.因此,虽然基于抽样方法和土壤侵蚀模型的土壤侵蚀普查方法也存在一定的问题,但与土壤侵蚀分类分级方法相比具有明显的优越性.%Soil erosion survey is important for land resources protection and natural disasters prevention. A new soil erosion survey method was proposed and Wuqi county in Shaanxi province was taken as a research object. 39 units were sampled by 1% uniform sampling ratio. Chinese soil loss equation (CSLE) was used to calculate soil loss, which was compared with soil loss estimated by "standards for classification and gradation of soil erosion". Average soil erosion modulus by two methods was 4 571 t/(km2-a) and 5 504 t/(km2-a) respectively, but the area and spatial distribution of soil loss in each grade were obviously different between them. More information was obtained on land use/land cover, soil conservation practices and soil properties by uniform sampling survey than that obtained by remote sensing and the information was properly representative of the whole survey region. Compared to "Standards for Classification and Gradation of Soil Erosion", soil erosion effecting factors include else factors such as soil erodibility, slope length and soil conservation practices were considered in CSLE. Therefore, survey results based on sampling and soil loss prediction model are more reliable than those based on remote sensing and "standards for classification and gradation of soil erosion".
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