A STUDY ON DESERTIFICATION OF WEST JILIN PROVINCE BASED ON REMOTE SENSING AND GIS TECHNIQUES

摘要

"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 suf-fered 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 westJilin Province is 819 100 ha, making up 12. 5% of the total land area. Among desertification types, in Jilin Provincelight desertification is the major, then is medium dersertification, hevey desertification is the least. According to the compari-son 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 increased6130 ha, making up 0. 8% of the desertification area, change scale is less than 1%. Evidently, desertification is con-trolled mostly, but some areas are continuing deterioration. The desertification process of China can be divided into threetypes according to origin nature, they are sandy steppe desertification, fixed sand area(sand land) activation anddunes transfer invasion. Reasons of desertification of West Jilin Province are analyzed, they include natural factors (suchas material source factors, chimate factors) and artificial factors(such as destroying grass to reclaim, steppe decreasinggreatly, illegally feeling shelter forest stands, constructing reservoir to influence eco-environment etc. ) . Some sugges-tions are put forward as follows: establishing the social project for ecological reconstruction of degenerated land; intensify-ing planning and management of land use, reverting farmland into forestland or pasture in a planned way. The key desertifica-tion control is to depend mainly on policy and management, then control techniques.