新疆艾比湖绿洲土地退化遥感动态监测

层次分析法是一种将决策者对复杂系统的决策思维过程模型化、数量化的过程.采用层次分析法,对影响和指示土地退化的生物量、归一化植被指数、土壤水分指数和土壤盐碱化4个影响因子进行分析.通过计算每个影响因子的权重,基于ASTER,SPOT,TM,MODIS产品以及野外调查数据等多源数据,对新疆艾比湖地区2000年8月至2004年8月的土地退化状况进行了评价,并且分析了层次分析法应用于土地退化研究的适用性及其优缺点.研究表明:艾比湖地区耕地退化现象普遍,占耕地总面积的55.78%,分布广,程度重.

Remote Sensing Dynamic Monitoring of Land Degradation in the Ebinur Lake Region

Analytical Hierarchy Process(AHP) is a process to make decision-thinking process of complex system numerable and structural.In this paper,the 4 factors affecting and indicating land degradation,including the biomass,NDVI,soil moisture index and soil salinization or alkalization,are analyzed using AHP.After calculating the weights of the factors affecting land degradation,the land degradation status in the Ebinur Lake region in Xinjiang Uygur Autonomous Region during the period from August 2000 to August 2004 is appraised based on the remote sensing means and the ASTER,SPOT,TM,MODIS products as well as the field investigation data.Moreover,the application,advantages and disadvantages of AHP in researching land degradation are also analyzed.After mapping the maps of land use/cover types and land degradation,it is found that the degradation of cultivated land in the study area occurs extensively,the area of degraded cultivated land occupies 55.78% of the total cultivated land area,and the land degradation is serious.Soil salinization or alkalization is the main cause of land degradation in the Ebinur Lake region,because discharge of the Jinghe River and Bortala River is reduced,the irrigation water consumption in the farming area in the lower reaches is decreased,the water area of the Ebinur Lake is shrunk,and the partial lake basin is dried up.The degradation of steppes and woodlands is not so significant.