Variation of Land Desertification and Driving Factor Analysis-Taking the Daan Region in the West of Songnen Plain as a Example

Land desertification is one of the main ecological environment problems, and threatening the safety of the ecological environment.Daan region is one of the typical desertification regions in the western Songnen Plain.Based on the GIS and Landsat TM images of 1986,1996 and 2000,the land use maps were complied.The desertification land was transfomed from the other land use types.In recent 15 years,variation of the land use was arable land and the desertification land were main land type;variance ratioof the desertification land was 31.97km~(2)/a,which ranked the first in all land use types.Until 2050,the result of Markov model's forecasting presented that the desertification land will account for 42.30% of the studied region;high-middle covered grasslands,waters and marshes will present different degree of degeneration,only accounting for 48.69%,24.71% and 22.74% respectively of the areas in 1986.The gray incidence analysis presented that the impropersocial and economic actions are main driving factors to the land desertification,such as road building,land reclamation;climate factor is the backgroundfactor,which ispropitious toland desertification process;The hydrological factor overlain human's improper exploitationand use are important factors to the land desertification.