江西德兴矿集区水系沉积物重金属污染的时空对比

对比研究矿山开采一定时段内区域环境污染的时空变化特征,对于动态监测矿山开采对区域环境质量的影响情况、污染趋势等,具有重要的科学意义和实际价值。本文在利用2004年野外采集与测试分析的330个水系沉积物样品重金属含量数据基础上,充分利用矿山开采早期(1989)的1:20万乐平幅(As、Hg、Cd、Cr、Zn、Cu、Pb)水系沉积物地球化学图,通过数据预处理,分别对样品采集点重金属元素含量的统计分析和地质累积指数法评价的基础上,采用GIS的三维空间分析功能,对比研究德兴地区水系沉积物重金属污染时空变化。研究结果表明,十几年来,矿山开采对区域水系沉积物已造成了严重的污染,主要集中分布在是德兴铅锌和铜钼矿区德兴河与大坞河流域及其周边地区、乐安河下游沿岸局部地区、西北煤矿区以及乐安河下游乐平附近的煤矿区。

Spatial-Temporal Variation of Heavy Metals Contamination in Sediments of the Dexing Mine,Jiangxi Province

The assessment of the spatial-temporal variation of regional environment contamination is very important for monitoring the environment quality variation and contamination trend. 330 sediment samples were collected in Dexing area and analyzed for As, Hg, Cd, Cr, Zn, Cu and Pb in 2004. Heavy metal levels were determined using inductively couple plasma-atomic emission spectrometry and X-ray fluorescence spectrometry. In order to compare the variation of heavy metals contamination between 1989 and 2004, the authors utilized the geochemical investigation maps compiled in 1989 and conducted studies at the same sampling locations of 2004 by such data preprocessing methods as scanning, vector and projection transform. The geoaccumulation index (Igeo) was used to assess the environment quality. Meanwhile, spatial-temporal contrast was performed using GIS 3-D spatial analysis of original testing data and geoaccumulation indexes. The results show that there existed only slight contamination of As, Cd, Cu and Pb in 1989, which was mainly concentrated within a small area along the middle-lower courses of the Dexing River and that there were different degrees of contamination of As, Cd, Zn, Cu and Pb in sediments in 2004, especially in the areas of the Dexing River, Dawu River and middle-lower reaches of the Le'an River, which were rarely contaminated in 1989. All this indicates that the extent and area of heavy metal contamination in sediments were much more serious in 2004 than in 1989.