Study On Method For Soil Conservation Monitoring Small Watershed-oriented

Soil erosion is the main cause for the global land degradation and also is the key problem resulting in the ecological environment deterioration, so N.N. FAO takes it as the principal problem of the global land degradation. It is far-reaching and profound for soil erosion to influence the ecological environment, which main directly brings on land productivity losing and crop yield declining, and also induces that reservoirs or rivers are filled up and water bodies are polluted by adsorbing pesticide or fertilizer with soil granule. In addition to the above threats to ecological environment, soil erosion may speed up land desertification because vegetation is destroyed, land surface becomes bare, reflectivity enhances. To control and decrease soil erosion, a lot of soil and water conservation measures were put in practice. For absence of monitoring management, the effect of conservation measures couldn't be trailed and evaluated. The global change, especially climate wanner, land use change, the response of precipitation and vegetation, change of water and carbon recycle will all affect soil loss deeply, finally brings the more challenge for soil and water conservation. The development of remote sensing and geographic information system provides a tool to monitor soil and water conservation effect at spatial or temporal multi-scale. So it is urgent to monitor soil and water conservation measures, and evaluate the effect of measures based on the technology of remote sensing.The paper expounded the meaning of small watershed management firstly, and soil conservation information system was constructed at regional scale. Based on the above, index system for soil and water conservation monitoring was constructed, and each index evaluation method was brought forward by technology of remote sensing and GIS.The main conclusion and innovation were as the following:(1) The research showed that vegetation fraction and leaf area index were not only the key factors restraining soil erosion, but also the most effective measurement factors for effect of soil and water conservation measures. Vegetation fraction describes the horizontal structure of vegetation, and leaf area index indicates the vertical structure of vegetation, then both of them could represent the function of constraining soil erosion, as well as used to monitor effect of soil conservation measures, and both indices can be evaluated and obtained from remote sensing readily.(2) During the construction of the index system for soil and water conservation, not only...