荒漠绿洲过渡带农业绿洲土地退化动态特征

为量化荒漠-绿洲过渡带农业绿洲土地退化动态，运用遥感与GIS技术，结合地统计学理论，对研究区自1960年土地开垦以来，耕地开发利用的结构变化以及1983～2005年土地利用类型与表层土壤(0～20 cm)土地退化时空变异规律关系分析研究。结果表明：农业绿洲经历4个阶段：过渡垦荒阶段、适度土地利用阶段、土地撂荒阶段、土地利用综合治理阶段。23年间农业绿洲景观改变的人为影响程度加剧是造成景观多样性和景观破碎化的主要动因。从1983～2005年，沿沙漠区向农业绿洲内部土地退化的程度降低，灰漠土退化面积明显高于盐

Dynamic characteristics of land degradation development in agricultural oasis of desert-oasis ecotone

To explore the evaluation of land degradation in agricultural region of desert-oasis ecotone,the spatial heterogeneity of topsoil(0~20 cm) and the relationship of such heterogeneity and land use type were studied using a combination of semivariogram and GIS methods.Results show that the development of oasis can be divided into four stages,i.e.,excessive land reclamation,moderate land use,land abandonment,land integrated management;human activities are the key factor that results in the increasing of landscape diversity and the fractionizing of the landscape in the last 23 years;from 1983 to 2005,the extent of land degradation was heavier in the area near desert resign than that in oasis;the area of land degradation in gray desert soil was larger than that in solonchak soil and aquert soil,and land degradation was weaker in the regions of bad quality than that in the regions of good quality.