长江三角洲典型区工业发展影响下土壤重金属空间变异特征

以长三角江苏省宜兴市为例,研究工业发展影响下土壤重金属空间变异特征。结果表明:(1)点源周围元素富集程度较强,其中固体点源周围含量最高,液体次之,气体相对较低;富集元素种类取决于点源排放废物类型;元素含量随距离的增加呈明显下降趋势,气体点源影响范围最大,固体次之,液体相对较小。(2)与点源相比,面源排放下元素富集程度较弱,元素含量随距离的增加变化规律不明显,但影响范围大。(3)面源排放下重金属空间分布的方向性,除受盛行风向的影响,还受到工业布局的影响;由于富集元素种类复杂,加之交叉复合效应,使其空间变异更为复杂,从而加大了重金属治理的难度。

Spatial Variability Characteristics of Soil Heavy Metals due to Industry Development of Typical Regions in Changjiang River Delta of China

The main objective of this study was to evaluate the spatial variability characteristics of soil heavy metals due to industry development of Yixing, an area with intensive industrialization in the Changjiang (Yangtze)River Delta of China. To do that, concentrations of heavy metals in soils with different distances from solid-, liquid-and gas point sources and non-point sources were measured. The results show that 1)different point sources can induce the strong enrichment of different heavy metal elements in soil and the concentration around solid point source is the highest, followed by liquid, and gas is relatively low. Concentrations of heavy metals in soils are significantly decreased with distance. And affected by the prevailing wind, the influenced area due to gas point source is the largest, followed by solid, and liquid is relatively small;2)compared with point source, the enrichment of heavy metals in soils around non-point source in industrial town is relatively weak, but its element types are complex. There are no significant changes of concentrations of heavy metals in soils with distance, but the influenced area is larger;and 3)affected not only by the prevailing wind direction, but also by industry layout, concentrations of soil heavy metals due to non-point source are of difference in different directions around industrial town. Due to the complexity of the enrichment element’s types of soil heavy metals and their combined effect in non-point source, the spatial variability is more complex. It means that taking effective measures to control non-point source is especially difficult.