寒地黑土典型县域土壤重金属空间分布及影响因素分析——以海伦市为例

The Spatial Distribution and Influencing Factors of Farmland Heavy Metals in the Cold Black Soil Region: A Case of HailunCounty

农田土壤重金属问题长期以来一直备受各界关注,科学揭示重金属空间分异特征及影响因素,成为新常态下耕地质量管理的重要组成部分。以海伦市耕地为研究对象,通过反距离权重插值法得到整个研究区8种重金属元素空间分布特征,利用地理探测器模型诊断自然因素、区位因素、生产生活因素对8种重金属空间分异的解释力。结果表明,Cr、Cu、Ni、Pb、Zn变异程度强,As、Hg、Cd变异程度较弱。8种重金属空间分异显著,不同重金属元素含量空间分布也存在差异,空间分布呈现西北向东南方向阶梯变化。不同影响因素具有不同的作用机制,对不同重金属元素空间分异的影响具有差异性,Hg、Cd、Pb、Zn的主要因素是区位因素与自然因素,As、Cr、Cu、Ni的主要影响因素是区位因素和生活生产活动因素,总体上区位因素的影响力大于生产生活因素,生产生活因素的影响力大于自然因素,土壤重金属在原本固有含量的基础上受到类人为因素的强烈扰动进行了新的空间排列,逐渐改变了原有的空间分布特征形成新的分布格局。

Heavy metal pollution of farmland soil has attracted a great attention for a long time. To scientifically reveal its spatial differentiation characteristics and influencing factors is an important part of arable land quality management. The spatial distribution characteristics of eight heavy metals were obtained with the method of IDW interpolation in Hailun City. Geographical detector was used to diagnose explanatory powers of natural, locational, production and living factors. The results showed that the variation degrees of Cr, Cu, Ni, Pb and Zn were greater than those of As, Hg and Cd. All of them had significant but different spatial gradient variations from northwest to southeast. Each factor had its unique mechanism that affected the spatial heterogeneity of heavy metals differently. The main influencing factors of Hg, Cd, Pb and Zn were location and nature, while those of As, Cr, Cu and Ni were location, production and living. In general, the influences of location factors were greater than those of production and living factors, and the influence of natural factors wasthe smallest. Affected by intense human disturbances, the inherent contents of soil heavy metals were shaped into a new spatial arrangement.