盐城海岸带表层土壤重金属的空间分布及其影响因素研究

以盐城海岸带为研究对象,分析了Cr,Cu,Fe,Mn,Ni,V,Zn,Co,Cd 9种重金属元素在二维空间分布的异质性,以及沿着经纬度方向的梯度变化,并通过主成分分析和元素区域背景值的分析,探讨重金属元素的可能来源.结果表明:自陆向海存在着逐渐减少的格局梯度,而在区域的北部分布着重金属元素的峰值；二维分析的结果表明,重...

Analysis of the spatial distribution and the influence factors of the heavy metals in the top soil layer of the Yancheng coast

We analyzed the heterogeneity in the spatial distribution of nine heavy metals (HM; Cr, Cu, Fe, Mn, Ni, Cd, V, Zn, and Co) in the coastal region of Yancheng. Inverse distance weighted interpolation was performed to study the gradient patterns of these metals from inland to coast and from south to north. Principle component analysis (PCA) and the background value analysis were then used to explore the possible sources of the heavy metals. It is found that the metal content decreased from inland to coast, while peaking in the northern region. The interpolation analysis indicated a high degree of heterogeneity in metal distributions. The heavy metal content was high in the northern region, regions with high human disturbance, inland of the coast, and the estuaries. The PCA results showed that the 9 HM could be divided into two groups. The PC1 included Cr, Co, Fe, Mn, Ni, and V, and the rotation sum of squared loadings was 63.31%. The PC2 was Cd, and the rotation sum of squared loadings was 22.81%. Compared with the background value, the PC1 was interpreted as HM from exogenous input, while the PC2 was composed of the heavy metal from background source. Cu and Zn were the metals with both exogenous inputs and background sources. At present, the ecological risks caused by heavy metals were not serious in this region. However, human induced HM deserves attention with increasingly intensified human activities in the region.