Land Salinization Monitoring Using Remote Sensing In West Section Of Jilin Province

Land salinization is the main problem of land degradation in western Jilin Province. This area appears serious ecological crisis, such as land desertification, soil salinization and vegetation degradation. To detailedly knowing the distribution of land salinization in western Jilin province, it can effectively prevent further land degradation, promoting the sustainable development of agriculture and economy. For this purpose, the author chose three phases which is 1970, 1985and 2000, each phase using landsat MSS, landsat TM and landsat ETM+ images as data sources, carried out salinization investigation based GIS technique in western Jilin province. The following is the main processes of this paper.1,At the beginning of the research, we downloaded the remote sensing images, then pre-processing the data such as geometric correction, band synthesis, spatial resolution fusion, image mosaic and clipping.2,Combining the present land-use map, soil type map, topographic maps and field trips, we interpreted the three periods'remote sensing images. For the purpose of improving the classification precision, this paper mainly adopted visual interpretation. The results of visual interpretation provided basis for the accurate analysis of the dynamic changes of saline and alkaline land.3,According to the principles of landscape ecology combining landscape indices (number Patch, mean patch size and patch density, etc), we further investigate the dynamic changes of saline-alkali land and analyze land fragmentation of the western Jilin Province. The results showed that: with the number of patches increased, fragmentation of the saline-alkali land was increased.4,Contraposing the changes in the ecological environment in the west of Jilin province, the author made an analysis on the driving force factors. Water and grassland resources is an important driving force of ecological environment evolvement in the study area. Because of the effects of precipitation, evaporation, surface water and groundwater, The water resources is lack. Due to overgrazing and predatory development to grassland in this area, ecosystem function is imbalance. The population growth and the way people using the land are the main driving forces for environmental changes.The results showed that: during the 30 years, the degree of land salinization is increased obviously in the west of Jilin province, and lake areas are decreased. Natural and human factors together aggravated the land salinization. Among natural factors, climate, landform, geology and hydrology play the most significant roles. However, the main factors causing this change are human factors, land salinization aggravate gradually with the increase of social pressure. Human irrational economic activities accelerate the process of land salinization. Agro-ecological geological environment is the source of land salinization. To effectively improve the current situation of salinization, we must make the use of land reasonablely, treatting the land salinization comprehensive is the only way to make the use of land resources sustainablely.