金昌市城区土壤重金属空间分布及潜在生态危害评价

通过对金昌市区范围内74处土壤的取样研究分析，结果表明：Cd、Cu、Ni、Pb、Zn5种重金属平均含量均超过当地土壤背景值，其中以Cu和Ni最为显著，其平均含量分别达到430mg／kg和361mg／kg；5种重金属变异系数均较大，其中Cu和Ni变异系数达到了11.5％和12.3％，属强变异性；采用克立格最优内插法得到金昌市表层土壤重金属含量的空间分布图，发现Cu和Ni呈局部污染态势，矿业开采和金属冶炼加工等工业活动是Cu和Ni最大的污染源；Pb、Zn和Cd在整个研究区域内都有积累，工矿活动和交通运输是金昌市Pb、Zn和Cd的共同污染源。潜在生态危害评价结果表明，该地区重金属污染已构成中度生态危害。

SpatialD istributionsof Heavy M etalsand Assessmentof Potential Ecological Risk in Jinchang Urban Area

The74 soilsampleswereanalyzed from Jinchang urban area. Theresultsshowedthattheaverage concentrationsofCd, Cu, Ni, Pb, Zn were more than thelocalbackground levels, especially Cu 430 mg/kg and Ni361 mg/kg. The variation ofcoefficientsofthe five elements were allin high levels, and Cu 115% and Ni123% ,to show strong variability. Sketch-mapsofspatialdistributionsofthe five heavymetalswereobtained by Kriginginterpolation toindicatethatmining and smelting had caused localpollution ofCu and Ni. The elementsofPb, Zn and Cd wereobviously accumulatedinthe whole urban area. Theindustrialactivitiesandtransportation had broughtabout;intermediate ecologicalrisk ofheavy metalpollution.