陆浑水库沉积物重金属空间分布特征及风险评价

为了解洛阳市饮用水水源地陆浑水库沉积物中重金属污染程度，采集32个点位的表层沉积物，分析6种重金属（Cd、Cr、Cu、Ni、Pb和Zn）的空间分布特征，并运用地累积指数法、潜在生态风险指数和聚类分析等方法对研究区重金属污染程度进行评价、生态风险评价及源解析.结果表明：Cd、Cu、Pb和Zn含量超过黄河流域河南段重金属土壤背景值，分别是其8.8、2.0、6.5、2.3倍，重金属存在明显富集，且主要污染集中于坝前区域.地累积指数法评价结果显示，Cd为强污染，Pb为中-强污染.潜在生态风险指数表明，陆浑水库沉积物重金属风险呈自上游至下游逐渐增强的趋势，总体处于高度生态危害，潜在生态风险指数均值达到312.94，其中Cd为主要贡献因子.富集系数法和聚类分析结果显示：Cd、Cu、Pb和Zn主要为人为源，Cr和Pb以自然源为主.总体而言，陆浑水库沉积物中重金属Cd和Pb污染相对较重，可能会对水库水环境构成威胁.

Spatial distribution characteristics and risk assessment of heavy metals in sediments of Luhun Reservoir

In order to understand the pollution degree of heavy metals in the sediments of Luhun Reservoir, the drinking water source of Luoyang City, the surface sediments were collected from 32 sites, the spatial distribution characteristics of six heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) were analyzed, and the methods of geo-accumulation index, potential ecological risk index and cluster analysis were used to evaluate the pollution degree of heavy metals, ecological risk assessment and source analysis, respectively. The results show that the contents of Cd, Cu, Pb and Zn are higher than the background values of heavy metals soils in the Henan section of the Yellow River Basin, which are 8.8, 2.0, 6.5 and 2.3 times, respectively. This indicates that heavy metals are obviously enriched and the main pollution is concentrated in the area in front of the dam. The evaluation results of geo-accumulation index method show that Cd is strong pollution level and Pb is medium-strong pollution level. The potential ecological risk index show that the risk of heavy metals in sediments are gradually increasing from upstream to downstream in Luhun Reservoir, and are in High ecological hazard, the potential ecological risk index is 312.94, in which Cd is the main contributing factor. The results of enrichment coefficient method and cluster analysis show that Cd, Cu, Pb and Zn are mainly man-made sources, while Cr and Pb are mainly natural sources. In general, the heavy metals Cd and Pb pollution in the sediments of Luhun reservoir is relatively serious, which may pose a threat to the water environment of the reservoir.