Abstract:

China is a country seriously affected by desertification it is the main content of combating desertification to protect the environmental resources forits sustainable development, to keep informed about the spatial and temporal changes of desertification for an effective implementation of macro control and management. For this purpose, the coverage of vegetation, the occupation ratio of bare sandy land and the soil texture are determined as three evaluation indicators of sandy desertification degree, depending on the configuration and ecotope of the earth surface. These 3 indicaltors show the productivity of a specific land from different aspects. A comprehensive mathematical model to evaluate sandy desertification degree was set up. According to the national conditions and the requirements of desertification monitoring by remote sensing, these evaluation indicators proposed in this paper audio-visual are, convenient and practical, which can be used not only to evalue the desertification degree of land but also to draw desertification distribution maps through visual interpretation on satellite images or on computer screen with digital imagety on pixel level. This monitoring and evaluation indicator system is testified to be applicable to classification and assessment on spatial distribution of desertification by using remote sensing and computer techniques after field investigation and verification in arid, semi-arid and dry affected sub-humid areas.

Key words: Desertification, Sandy desertification, Evaluation indicator