城市扩张过程对土壤重金属积累影响的定量分离

定量提取人为活动对土壤重金属积累的影响是进行土壤污染模拟的基础。本文研究了1949年来宜兴城区的扩张过程及在其影响下土壤中Cd、Cu、Pb和Zn等重金属的积累过程。利用变量分离法提取了重金属含量中的人为影响分量和自然背景分量,并估算了城市扩张影响下的积累通量。研究结果发现随着宜兴城区扩张快速,土壤中的重金属元素含量随着城市建设年限的增长而升高。变量分离法较成功的解释了重金属元素积累的影响因素,Cd、Cu、Pb和Zn的人为影响分量的均值分别占各实测含量均值的16.6%、18.4%、33.22%和2.7%。空间分布上4种重金属元素的趋势分量沿城市扩张方向均表现出明显的递减趋势,而自然背景分量无明显的空间变化趋势,主要受土壤理化性质的影响。最后,进一步推算了土壤重金属元素输入通量空间变化方程,这可为进一步模拟城市化背景下重金属积累提供有效的参数。

Quantitative partitioning of impacts of urban sprawl process on heavy metal accumulation in Yixing, China

Quantification of the impacts of human activities on accumulation of heavy metals in soil is essential to modeling of soil pollution.Urban sprawl process of Yixing city,China,since 1949,and its impact on accumulations of Cd,Cu,Pb and Zn in the soil were studied.The method of variable partition was used to separate anthropogenic effect from the impact of natural background and accumulative flux as affected by urban sprawl was estimated.Results show that during the past three decades,Yixing city has been grow...