中文摘要：

本文采用放射性核素Cs-137测年结合碳球粒定年方法，建立大冶市三里七湖浅孔岩芯的年代序列。基于沉积物中10种重金属元素、磁化率和粒度等多指标记录以及大冶市的社会经济统计资料，采用地质累积指数和主成分分析方法，重建了近60年大冶市三里七湖重金属污染演化历史。结果表明三里七湖生态环境演化可以分为三个主要阶段：1951年以前，重金属含量低，反映工农业发展水平较低、人为干扰少，湖泊生态环境处于自然演化阶段；20世纪50年代以来，流域工农业活动发展加快导致重金属富集，尤其是1984年以后，重金属富集进一步加剧；2000年以来Zn、Cd、Ni、Fe、Cr等元素的含量仍呈升高态势，而Cu和Pb含量下降，反映人为活动干扰仍然十分强烈，同时冶炼技术进步和环境治理可能减少重金属污染。相关分析结果显示重金属地质累积指数与工业和农业产值显著相关，且与工业产值相关系数更高。这表明工农业活动引起的重金属输入是三里七湖重金属污染的诱因，其中工业活动影响更大。

英文摘要：

The methods of radioisotope 137Cs and spheroidal carbonaceous particles （SCP） dating were used for establishing the chronology of a short sediment core from Sanliqi Lake （Daye City, SE China）. The last 60-year history of heavy metal contamination was reconstructed based on multiproxies （i.e., grain size, magnetic susceptibility （Xlf）, 10 species of heavy metals） and historical archives, with the method of principal components analysis （PCA）, geo-accumulation index and correlation analysis. Three distinct phases were identified in the sedimentary profile. Between 1945 and 1951, low values in sedimentary heavy metal concentrations, SCP concentration and Zlf indicated poor development of the industry and agriculture, suggesting that the lake was in a natural status. From 1951 to 2000, the expansion of the industry and agriculture caused rapid accumulation of heavy metals, coarse particles, SCP and an increase in 2% In addition, heavy metal enrichment accelerated after 1984. The decoupling of 10 species of heavy metals since 2000, with rising trends in Zn, Cd, Ni, Fe and Cr whilst declining patterns in Cu and Pb, indicated strong human disturbances, as well as slight environmental improvement attributed to improved smelting technology and environmental treatment. The significant correlations between the geo-accumulation indexes and industrial and agricultural outputs revealed that industrial and agricultural activities resulted in environmental degradation in Sanliqi Lake. Industrial activities imposed a more important role on heavy metal pollution than agricultural production.