矿区农田土壤重金属的空间变异:以陕西省某金矿区为例

Spatial Variability of Farmland Soil Heavy Metal in the Mining Area:Taking agold mine in Shaanxi as a case

为矿区周边农田环境质量及安全生产管理提供依据,在陕西省某金矿区外农业生产区采用地统计学和地理信息系统(GIS)相结合的方法,研究了表层46个样点土壤Hg、Cd、As的空间变异特征及空间分布规律。结果表明:1)研究区受Hg、Cd污染严重,As污染程度轻。2)3种重金属在一定范围内存在空间自相关性,相关程度为Cd>Hg>As,土壤Hg、As的最优拟合模型为高斯模型,Cd为指数模型。3)3种重金属含量估测值的拟合分布图显示As分布均匀,无高含量集中区;Hg和Cd分布有明显的地域性,东南高,西北低。

In order to provide a basis for the farmland environmental quality and safety production management around the mining area,the authors researched the spatial variation characteristics and distribution of Hg,Cd,As in 46soil samples in an agricultural area near a gold mine in Shanxi Province by using a combination methods of geo-statistics and geographic information system(GIS).Results:Hg and Cd contaminated seriously in the study area and the As polluted light.Spatial autocorrelation of the three heavy metals existed in a certain range and the relevant degree was Cd>Hg>As,the optimal fitting model for Hg and As in soils was Gaussian model,and for Cd was exponential model.The distribution maps of heavy metal contents showed that As distributed evenly in the study area and did not have high level centralized distribution,but the distribution of Hg and Cd had an obvious regionalism with a high level in southeast and a low level in the northwest.