Technical Framework on Monitoring and Assessing of Land Degradation
SUN Wu 1, LI Sen 2 (1.Dept. of Geography, South China Normal University, Guangzhou Guangdong 510631; 2. Dept. of Geography, Foshan University, Foshan Guangdong 528000)
Based on the review of the advance on monitoring and assessing of sandy desertification at home and abroad since the late 1990s, the paper draws an outline of theories and technical lines after conducting desertification evaluation in several regions. Three of theories are important, respectively representing absolute, relative and diversity degradation, they are global assessment of human induced soil degradation(GLASOD), the assessment of the status of human induced soil degradation in South and Southeast Asia(ASSOD), and the theory put forward by Moscow State University and Russia Academy of Science(RUSSIA). Two technical lines are either using image processing software through supervised and unsupervised classifications or selecting different weighed indicators from RS and GIS. Combining the situation in China and under guidance of absolute degradation theory, the paper puts forward the technical framework for monitoring and assessing sandy desertification of China, which include the definition of degradation baseline with temporal and spatial scale, the establishment of indicators database based on 3S for the typical desertified land of all levels and the integration of computer image processing, GIS and ES.