库车县土壤微量元素空间变异特征分析

Analysis of Spatial Variability Characteristics of Soil Trace Elements in Kuqa County

基于GIS与地统计学相结合的方法,分析了库车县耕层土壤微量元素的空间分布特征与影响因素。结果表明:1研究区土壤有效锰的平均含量最高,有效锌的平均含量最低,4种微量元素均为中等变异程度,微量元素之间存在显著的相关关系。2通过半方差函数理论模型分析,有效铁和有效铜的最优理论模型为指数模型(R2为0.859和0.862),有效铜和有效锌的最优拟合模型则为指数模型(R2为0.950和0.907)。3从空间格局分布来看,有效铁和有效锌,呈斑块状分布,有效锰和有效铜则以片状分布为主。土壤有效态微量元素的含量呈现出四周高-中心低的空间分布特征,其空间变异主要由地形、土壤类型以及水文条件所影响,此外,还与施肥、耕作和管理水平等随机因素有关。

Based on the combination of GIS and geo-statistics analysis method,the spatial distribution characteristics and impact factors of soil trace elements in Kuqa county were analyzed. The results showed that：（ i） The average content of available Mn of soils was the highest in the tested area,the average content of zinc was the lowest,four kinds of trace elements had moderate variability,and there were significant correlations between their trace elements.（ ii） The theoretical model results of semi-variance displayed： the optimal model of available Fe and Cu were index models（ R2 were equal to 0. 859 and 0. 862,respectively）,the best fitting model of available Cu and Zn were exponential models（ R2 were equal to 0. 950 and 0. 907,respectively）.（ iii） From the perspective of spatial distribution,available Fe and Zn were in spot distributions,and available Mn and Cu were mainly in patchy distributions. The spatial distribution of soil available trace element contents showed： high around-low center. In addition,the spatial variability was mainly caused by terrain,soil type and hydrological conditions,also relating with random factors of fertilization,cultivation and management level.