【摘要】 为阐明社会经济发展对湖泊沉积物重金属时空富集的影响,采集了长江中游湖南省大于10km²的湖泊沉积物,通过¹³⁷Cs和²¹⁰Pb放射性核素计年法、地化学背景值稳定层法及多元统计学法解析了湖南湖泊沉积物5种重金属的背景值;基于背景值结果,识别了重金属高背景区不同经济发展水平的岳阳南湖（城区）、黄盖湖（近郊）和华容东湖（远郊）的主要生态毒性风险元素,利用岭回归估计构建STIRPAT扩展模型,分析了人口总数、人均GDP、城镇化率、第二产业占比、第三产业占比、采掘业与制造业生产总值等6种社会经济发展指标与特征重金属的时空关系.结果表明,沉积物中Cr、Cu、Zn、Cd和Pb的地化学背景值分别为98,30,78,0.22和26mg/kg,分别是湖南土壤背景值的1.46,1.11,0.82,2.75和0.96倍;地累积指数显示,重金属总生态毒性风险顺序为岳阳南湖>黄盖湖>华容东湖,Cd是岳阳地区湖泊生态毒性风险主要贡献元素;STIRPAT扩展模型中,人口总数、城镇化率、实际人均GDP、第二产业占比、第三产业占比、采掘业和制造业生产总值的标准化系数分别为0.1396,0.0969,0.1922,0.1367,0.1264和0.1929,表明采掘业与制造业、人均GDP、人口总数对Cd污染影响最大.因此,采用土壤背景值评估湖泊生态环境不太准确,流域人口城镇化过程中采掘与制造业对湖泊Cd的富集量影响较大.更多还原

【Abstract】 To investigate the impact of economic development on the spatial-temporal distribution characteristics of heavy metals in lake sediments,lakes （≥10km²） in Hunan Province along the middle reach of the Yangtze River were collected.The sediment background values （GB） of heavy metals were analyzed by ¹³⁷Cs and ²¹⁰Pb radionuclide methods,geochemical background method,and multivariate statistic method.According to the results,the main toxicity risk element in Yueyang South Lake （urban area）,Huanggai Lake （suburb）,and Huarong East Lake （suburb） with different economic development levels were identified.Ridge regression estimation based on the STIRPAT extended model was used to investigate the spatial-temporal relationships between socio-economic indicators （total population,actual GDP per capita,urbanization rate,secondary industry ratio,tertiary industry ratio,mining and manufacturing） and the most important pollutants.The results showed that the GB of Cr,Cu,Zn,Cd and Pb were 98,30,78,0.22 and 26mg/kg,respectively,which were 1.46,1.11,0.82,2.75 and 0.96 times of the soil background values in Hunan.The total ecological risk posed by the metals in the study area followed the trend Yueyang South Lake>Huanggai Lake>Huarong East Lake.And Cd was the most widely contributed and most concentrated element.In the STIRPAT expansion model,the standardized coefficients of the total population,urbanization rate,actual GDP per capita,the secondary industry ratio,the tertiary industry ratio,the mining and manufacturing were 0.1396,0.0969,0.1922,0.1367,0.1264 and 0.1929,respectively,indicating that the mining and manufacturing production,actual GDP per capita,and the total population had the greatest impact on Cd pollution.Therefore,the mining and manufacturing had a great impact on Cd pollution in lakes.The conclusion was not accurate to assess the lake sediment risk through soil backgrounds.This study provides important guidance for watershed environmental baseline study,pollution prevention,environmental management,pollution control,and especially supporting the protection of the Yangtze River.更多还原