为探明西北干旱区土壤水分和盐分的空间分布特征，在乌兰布和沙区布设38个样点，获取3个土层(0～10cm、10～30 cm、30～50 cm)的土壤含水率和土壤EC数据，利用空间信息科学——统计学，同时结合经典统计学与长序列上的谱分析，对干旱区土壤水盐参数的空间分布特征进行分析。结果表明：干旱的乌兰布和地区土壤含水率、土壤EC的变异系数分别介于38%～57%和35%～98%，均属于中等偏弱变异程度，且两者变异系数随土层深度自上而下逐渐增大；研究区0~50 cm土层的土壤含水率和EC均值分别为7.09%～12.01%和0.16～0.28 μS/cm，30～50 cm 土层含水率均值最大，对于整个干旱沙区，土壤水分和盐分含量普遍较小；由块金系数可知各深度土层的土壤含水率及EC值变化具有较强的空间相关性，最小变程大于采样间距，网格布设基本满足空间分析要求，但应缩小采样间距，增加采样点，以寻求最佳采样点间距；克里格插值结果显示，不同土层含水率呈逐月升高的趋势，土壤盐分则逐月降低，5月土壤表层（0～10 cm）盐分均值最大、分布最广；谱分析结果显示EC值在含水率序列上随生育期呈现先长程正相关（5月）后长程负相关（6-8月）。
英文摘要:
In order to find out the spatial distribution characteristics of soil water and salt in the arid area of Northwest China, 38 sample sites were set up in Ulanbuh sandy area to obtain soil water content and EC data of three soil layers (i.e. 0-10 cm, 10-30 cm, and 30-50 cm respectively). The spatial distribution characteristics of soil water and salt parameters in the arid area were classified using geostatistics of spatial information science, combined with the classical statistics and long-range spectrum analysis. The results showed that the coefficients of variation of soil water content and EC were 38% - 57% and 35% - 98% respectively, both showing moderate and weak variations, and the variation gradually increased with the depth of soil layer from top to bottom. The average of soil water content and EC values were between 7.09%-12.01% and 0.16 μS / cm-0.28 μS / cm, respectively. The soil layer of 30-50 cm had the greatest average values. In the whole studied area, both soil water content and salt content was relatively small. There were strong spatial correlations between soil water content and EC in each depth of soil layers judged from the nugget coefficients, the minimum variation was greater than the sampling interval, and the grid layout basically met the requirements of spatial analysis. It is suggested to reduce sampling interval and increase sampling sites in order to find the optimal sampling site interval. Kriging interpolation results showed that the water content of different soil layers increased and the soil salt decreased month by month. The average values of salt in the soil surface layer (0-10 cm) were the largest and distributed the widest in May, 2018. The spectrum analysis showed that the EC had a positive correlation with the growth period in May and then a negative correlation from June to August, 2018.