盐城滨海滩涂表层沉积物重金属生态风险评价

Ecological risk assessment of heavy metals in surface sediments in Yancheng coastal mudflat

使用Arc GIs软件对江苏盐城国家级珍禽自然保护区内核心区外围滩涂表层沉积物中的镉(Cd)、铬(Cr)、铜(Cu)、铅(Pb)、锌(Zn)及镍(Ni)6种重金属含量及其分布特征进行空间插值分析,并采用环境风险指数法(HPERI)和Hakanson潜在生态危害指数法(ERI)进行重金属生态风险评价,旨在为滨海湿地生态系统健康和环境保护提供科学依据,为滨海保护区的开发利用提出合理化建议。研究结果发现,Cr、Ni、Pb的含量均高于背景值;Cu、Zn、Cd、Pb 4种重金属含量均低于国家I类标准,属I类沉积物;Cr为Ⅱ类沉积;环境风险指数法表明该区域Cr对环境污染的影响最大,综合环境风险由东南至西北呈现先增大、后减小、再增大的趋势;Hakanson潜在生态危害指数法结果表明Cd的潜在生态危害最大,综合潜在生态风险与环境风险指数的变化规律大致一致,以新洋港入海口和渔业活动最密集处为最高。六种重金属的综合潜在生态危害指数RI值均在40以下,远小于150,总体也属非常轻微程度的生态危害。

Kriging interpolation analysis was conducted with Arcgis 9.3 to find out the distribution characteristics of six heavy metals including Cr, Ni, Cu, Zn, Cd, and Pb, in the surface sediments in the core area of the Yancheng National Rare Bird Nature Reserve. Environmental Risk Index （ ERI） and Hakanson Potential Ecological Risk Index （ HPERI） were used to assess their extents of pollution in this area. According to the research, Cr was found to contribute the most to the pollution status based on ERI method. Cd produced the greatest potential ecological harm according to HPERI method. ERI and HPERI were both high in the southeast and northwest, where human impacts were significant, which suggested that there was a tendency that pollution caused by human activities had turned into the most important impacting factor on the environmental quality in the core area of the Yancheng National Nature Reserve.