典型干旱区绿洲植被-地下水埋深-土壤盐分的空间分异与耦合分析

The Spatial Variability and Coupled Analysis for Groundwater Depth,Soil Salinity and Vegetation of A Typical Oasis in Arid Area

干旱区绿洲内部植被与水土的相互作用直接影响到绿洲的稳定。为了探索绿洲植被-地下水埋深-土壤盐分的空间分异与耦合关系,本文以典型干旱区绿洲——新疆和田地区克里雅绿洲为实例,根据归一化植被指数(NDVI)、地下水埋深和土壤盐分数据,采用地统计、3S技术、回归分析及K-S检验等方法,在耦合系数模型的基础上,研究植被覆盖、地下水埋深及土壤盐分的空间分异规律及相互关系。结果表明:(1)植被覆盖空间格局围绕克里雅河新老河道、平原绿洲内稻田区和绿洲外围过渡带等景观呈梯度分布;(2)克里雅绿洲区域内地下水埋深整体上由北向南逐渐增加,土壤表层含盐量整体上由西至东呈带状分布;(3)研究区植被覆盖、地下水埋深及土壤盐分的空间分异趋势比较一致;(4)克里雅绿洲地下水埋深、土壤含盐量及植被覆盖指数三者存在较高的耦合关系,耦合度在0.6以上,属中级协调。

The interaction between vegetation and water-soil affects aosis＇ s stability enormously in arid area.We studied,with taking Keriya Oasis as a case,the spatial variability and interaction for groundwater depth,soil salinity and vegetation based on NDVI（ Normalized Difference Vegetation Index） data,groundwater depth data,soil salinity data,with the methods as geo-statistics,3S,regression analysis,K-S test,and the coupling coefficient model. The results showed that： The spatial pattern of vegetation presented a gradient distribution around new and old riverways,paddy area,and ecotone; The groundwater depth had a overall increased trend from north to south,and the surfacing soil salinity had a overall zonal trend from west to east; The vegetation,groundwater depth and soil salinity had the same trend on spatial variation; We established a coupling equation between groundwater depth,soil salinity and NDVI,and the coupling degree was above 0. 6,as a mid-level coordination.