Study On Dynamic Change Of Vegetation And Desertification Assessment In Zhenglanbanner Based On RS And GIS

Based on TM image, investigation and statistics data, the process of vegetation cover change, desertification assessment and driving mechanism of Zhenglanbanner are profoundly studied based on a case study carried out in Zhenglanbanner, Inner Mongolia, by using integrated TM image processing, quantitative analysis and model simulation techniques.To estimate the Zhenglanbanner vegetation cover from TM images, a model is set up using NDVI and a dense sub-pixel vegetation model. The quantitive and spatial characteristics of vegetation cover change over Zhenglanbanner in 1987 and 2001 are studied on the basis of above approach, and the results indicate that the area of high cover vegetation has increased greatly and the area of medium, low, cultivated vegetation have steadily increased from 1987 to 2001. The type of vegetation cover change focus on vegetation degrading, which is 85.17% of the area that has experienced the change of vegetation coverage type. The tendency of vegetation cover over zhenglanbanner is generally decline, which lead to serious deterioration of its ecological enviroment.Applied the rain-use efficiency of vegetation as a key assessment indicator, regarded the situations in 1987 as a benchmark, the desertification degree over Zhenglanbanner in 2001 is assessed. The results indicate that desertification area is more than half of the assessment area in 2001, the situation of desertification is serious, however, the area of medium and less desertification area is 89.9% of the desertification area, it is implied that desertification degree of the assessment area is not serious in 2001, the difficulty to control desertification is relatively small.