中文摘要：

以黑河下游地下水波动带为研究区，根据64个样点的实验数据，采用地统计分析法对区域土壤盐分空间变异函数理论模型进行了选择，同时还利用GIS交叉验证（Cross—Validation）对目前较为薄弱的空间插值方法的适用性选择问题进行了分析。并在此基础上对整个区域土壤盐分空间分布进行了模拟，进而分析了其空间变异特征。结果表明：（1）受地下水影响，黑河下游地下水波动带土壤盐分含量整体较高，且其空间分布具有明显的变异特征。在沿河流流向及垂直于河流流向方向上，各盐分要素在整体规律性变化基础上都存在局部性变异，且这种局部性变异在垂直于河流流向方向上比河流流向方向更显著；（2）各盐分要素的变程为本研究今后合理布置采样点提供了参考依据，同时也为黑河下游地区水文及生态研究提供了有关研究尺度的参考信息；（3）研究区土壤盐分空间分布模拟也为该区植被恢复提供了必要的土壤盐分信息，这对本区乃至整个黑河下游植被恢复及生态重建工作都具有重要指导意义。

英文摘要：

The vegetation plays an important role in maintaining the safety of arid ecosystem. The groundwater fluctuant region is the region where the water level and the extent of affected area by groundwater are changed markedly. It is also a principal region to restore injured vegetation and ecosystem. The soil water and salt conditions are determinant for vegetation in the arid region. So, the study of spatial feature of soil salinity which is affected by groundwater can offer directive significance for restoring regional vegetation in the arid region. Taking the groundwater fluctuant region of the lower reaches of the Heihe River as study area, based on the experimental data of 64 soil samples, the fitted experiential semivariogram models were selected using the geo-statistic methods. And the CrossValidation of GIS was introduced to resolve the problem how to select optimum interpolation method. Then, the pattern of spatial distribution of soil salinity was simulated utilizing the fitted theoretical models and the optimum interpolation method. Lastly, the characters of spatial variance of soil salinity were analyzed based on this pattern. From this study, some conclusions can be drawn out as follows ： （ 1 ） under the effect of groundwater, the content of soil salinity is very high and the variance characters of soil salinity are very obvious in the spatial distribution. Along and across the direction of the river water flowing, all elements of the soil salinity are characterized by the partial variation on the basis of the whole regularity variation. And this partial variation is clearer across the direction of the soil salinity offers a reference for future study how to locate the points for collecting the soil samples. And the range provides the referenced scale information for the hydrological and ecological study ; （ 3 ） the simulation of the soil salinity＇s spatial distribution can offer the information of soil salinity in every point of study area for restoring regional vegetation, it is important r