城市水源地生态风险评价

鉴于保护城市水源地的重要性，参考美国环境保护署(US EPA)的生态风险评价导则，提出城市水源地生态风险评价的基本方法，该方法将城市水源地生态风险评价分为研究区的界定、受体及评价终点分析、风险源分析、暴露及危害分析、综合风险评价等步骤. 以贵阳市的主要水源地——红枫湖为例进行生态风险评价，将红枫湖分为南湖、中湖和北湖3个研究区域，识别出主要生态风险源为点源污染源、面源污染源、湖泊沉积物、酸沉降、干旱和石漠化等. 以水质变化为评价终点，通过暴露、危害分析，采用基于因子权重的评价方法进行综合评价. 结果表明:南湖的生态风险值最高，为0.632 4；北湖的风险值为0.344 9；中湖的风险值相对较低，为0.333 5. 研究还发现，对红枫湖生态风险值贡献较大的因子为红枫湖湖水营养物P和沉积物中的重金属，二者的权重分别为0.205 9和0.175 1. 应用该方法可以找出对水源地危害较大的生态风险因子，更好地保护水源地. 

Ecological Risk Assessment for Urban Water Sources

To protect water sources,this study proposes a framework of ecological risk assessment(ERA) based on the Guidelines of Ecological Risk Assessment of the US EPA.The main procedures of the ERA include: confirming risk assessment range,endpoint and receptor assessment,risk source assessment,hazard assessment,exposure assessment,and synthesis risk assessment.The proposed method was applied to assess the ecological risk of Hongfeng Lake,which is the main water source of Guiyang City.The Lake is divided into thre...