Spatial-Temporal Variation of Heavy Metals Contamination in Sediments of the Dexing Mine,Jiangxi Province
江西德兴矿集区水系沉积物重金属污染的时空对比

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.