本文在调查了米脂县土壤侵蚀现状和土地利用现状的基础上,对目前由于不合理的土地利用结构和耕作方式而造成人为加速侵蚀的问题作了分析,并认为土壤侵蚀是制约黄土高原丘陵沟壑区农业经济发展的根本原因。构成黄土高原丘陵沟壑区的基本地貌组合单元是小流域,它几乎包括了该区域的所有土地类型、地貌要素以及土壤侵蚀类型。因此以小流域为侵蚀系统的研究边界,分别对峁边线以上的面蚀、细沟侵蚀区和峁边线以下的沟蚀、重力侵蚀区进行土壤侵蚀的遥感定量分析,建立相应的侵蚀定量模型。在此基础上,探讨了为土壤侵蚀动态监测、水土保持和土地资源合理利用决策服务的土壤侵蚀信息系统的设计思想。该系统以小流域为基本设计单元,侵蚀定量模型为专业接口,重点考虑了系统的地学分析和专业数学模型的建立与应用功能。

On the basis of a survey of soil erosion and land use with remote sensing, severe accelerated erosion is considered to be the primary cause of poor agricultural ecnomical condition in the hill and gully region of the Loess Plateau. It is a result of intensive cultivation and unreasonable land use. Both of these two have a long history. This paper tries to introduce a methodology of quantitative analysis of soil erosion with remote sensing information. Small watershed is taken as the study unit of the erosion system. Thus, two mathematical erosion models which predict the sheet erosion, the rill erosion and the sediment yield of small watershed are developed, according to systematical experimental data and field survey results as well as remote sensing data. Finally, the principles of Soil Erosion Information System (SEIS) are discussed. They are used for dynamically monitoring soil erosion, land use planning and soil conservation.