上海长兴岛典型农用地土壤重金属特征分析与生态风险预警评估

Characteristics of Heavy Metals Pollution and Ecological Risk Warning Assessment of Agricultural Soil in Changxing Island,Shanghai

以上海长兴岛典型农用地为研究对象,对采集的104份土壤样品中的4种重金属(Cu、Zn、Pb、Cr)进行检测,分析农用地表层和底层土壤中4种重金属的含量水平、污染特征和污染成因,并采用潜在生态危害指数法进行生态风险预警评估。结果表明,长兴岛农用地表层和底层土壤中4种重金属的空间差异不大,表层土壤相比底层土壤受干扰略严重,但只受到轻微污染,即土壤中重金属含量超标主要归因于自然因素。表层和底层土壤重金属潜在生态危害指数均<20,均呈轻微生态风险态势,表明长兴岛农用地有重金属轻度富集的现象。

104 soil samples from Changxing Island, Shanghai are analyzed concerning 4 kinds of heavy metals （Cu, Zn, Pb, Cr）. The concentrations, the pollution characteristics and sources of soil heavy metals in the topsoil and subsoil are obtained. The potential damage index method is used for ecological risk assessment. The results show that the topsoil is a little more dis- turbed than the subsoil, but both are only slightly polluted which indicating that the heavy metals in soil of Changxing Island are mainly derived from the natural factors. The potential ecological damage indexes of heavy metals in the topsoil and subsoil are both less than 20,indicating a slight ecological risk trend. The research shows that enrichment of heavy metals exists in the agricultural land of Changxing Island.