Evaluation Of Cbers-01's Data And Appraisal In Land Desertification Monitoring

CBERS-01 is an earth resource satellite developed by China and Brazil, which lifted off in 1999.The CBERS-01 spectrum data of 2,3,4 bands are consistent with corresponding wave band of LANDSAT TM, so we can carry on a comparison between them. We Use the CBERS-01 data and earlier data to monitor land desertification in the project. The fellow is major result:1. Based on wave band analysis of CBERS-1 data, we found that the 2nd band has inerratic stripe noise, the 3rd band has irregular spot noise, the 4th band texture is clear, and the combination image of band 2, 3, 4 has a displacement. According this, we use noise reduction and band matching methods to give the solution.2. After surveys, the ground pix-resolution of CBERS-1 data in Gulang is 19.97m, it's higher than TM data; The characteristic resolution of combination image is higher than corresponding combination image of TM, so the combination image of CBERS-1 has more information content, the data can be used in desertification monitor.3. Based on 1987 TM and 2000 CBERS-1 image data, the land-use type and the Status of desertification in Gulang County were analyzed. The monitor results indicated that: from 1987 to 2000,the county-wide land utilization change showed, the large area of clay-Gobi and fixed sandy land was opened up into irrigable land in the south of Tengger desert, in southern mountainous area and middle drought plain area, because many dry lands converted into forest and grassland, the county-wide farmland area reduced; The area of irrigable land and middle-low coverage grassland increased, the mountain arid land and plain arid land reduced a lot, the Gobi and fixed sandy area reduced. The county-wide high-coverage grassland and natural forest all located in higher elevation mountain area, its area decreased because of over grazing and exploitation; the total area of sandy land reduced, but some sand dune became shifting sandy land because of sandy grazing and continues drought climate in recent years. In Gulang County, the desertification can be divided into three types, wind erosion, water erosion and sandy degradation. The total area of desertification land decreased, but various types change is different, The area of extremity desertification land increased about 10525.6hm~2,the area of heavy desertification land reduced about 47348.02hm~2, the moderate desertification land increased 50064.75hm~2, the mild desertification educed 22153.17hm~2; In desertification land change, the change rate of half-mobile sandy land achieves 81.60%, was the biggest, The second is the fixed sand, achieves 55.73%, it showed that artificial activity affects greatly on desertification development.4. Gulang is an mid-desertification County, its desertification index was 2.209 in 1987 and 2.162 in 2000, that decreased by 0.047.From 1987 to 2000, In its governs 25 administrative areas, the desertification index reduced in15 villages and towns, two of them reducing scope surpass 0.5, and one fell below 1; The desertification index increased in 10 villages and towns, and the increasing is lowly. Meanwhile, in non-administration Tengger desert, because of poor management, the desertification development speed is quickest, has achieved the heavy desertification degree.5. In Babusha Eco-construction area, the desertification tendency is the same with county-whiled. The reduced area of farmland is mainly drought plain land and mountain dryland, and the increased area is mainly irrigable land; The total area of sandy land decreased; From 1987 to 2000, the desertification index reduced from 1.753 to 1.635, the desertification reverting is higher than county-wide level. It indicated that under artificial intervention, desertification may reverse.6. The reason of modern desertification in Gulang County is various, and the human activity is the main factor. The population growth caused the increase demand of land resource, upstream reservoir establishment reduced the surface runoff, lead to desertification, the unreasonable land utilization lead to rapidly degeneration of pasture. Based on desertification cause, we can prevent and control desertification by controlling population growth, improving the human quality, enlarging desertification preventing and controlling investment, establishing key ecology project, adjusting the local industrial structure, using land resource reasonably, enhancing management, strengthen the law enforcement and so on.