A study on desertification of west Jilin Province based on remote sensing and GIS techniques

“West Jilin Province” in this paper means Zhenlai, Baicheng, Taonan, Da’an, Tongyu, Fuyu, Songyuan, Qian’an, Changling, also includes Gongzhuling, Shuangliao, Lishu, Siping and Nong’an which have been suffered from desertification. In west Jilin Province there are three sand zones passing through, they are Xiang(Xianghai)-Wu(Ulan Tug) sand zone, Hai-Feng sand zone, and Tao’er River right bank sand zone. The desertification area of west Jilin Province is 819 100 ha, making up 12.5% of the total land area. Among desertification types, in Jilin Province light desertification is the major, then is medium dersertification, hevey desertification is the least. According to the comparison of the interpretation results of the Landsat images of the 1980s and the 1990s by remote sensing and GIS techniques, it can be seen that the desertification area in west Jilin Province basically didn’t change on the whole, only increased 6130 ha, making up 0.8% of the desertification area, change scale is less than 1%. Evidently, desertification is controlled mostly, but some areas are continuing deterioration. The desertification process of China can be divided into three types according to origin nature, they are sandy steppe desertification, fixed sand area(sand land) activation and dunes transfer invasion. Reasons of desertification of West Jilin Province are analyzed, they include natural factors(such as material source factors, chimate factors) and artificial factors(such as destroying grass to reclaim, steppe decreasing greatly, illegally feeling shelter forest stands, constructing reservoir to influence eco-environment etc.). Some suggestions are put forward as follows: establishing the social project for ecological reconstruction of degenerated land; intensifying planning and management of land use, reverting farmland into forestland or pasture in a planned way. The key desertification control is to depend mainly on policy and management, then control techniques.