葫芦岛市连山区、龙港区土壤重金属汞、铬及镍的空间分布及污染评价

Spatial Distribution Contamination Evaluation of Hg,Cr and Ni in Soil of Lianshan and Longgang Districts,Huludao City

本文利用地理信息系统及地统计学,对葫芦岛地区土壤中Hg、Cr、N i的污染状况进行了分析。结果表明:土壤Hg、Cr、N i的理论模型均为球状模型。N i的C0/(C0+C)为56.6%,说明N i体现为中等的空间相关性,Hg、Cr的C0/(C0+C)均为5.8%,说明这2种重金属体现为强烈的空间相关性。在已有监测数据的基础上,通过克里格插值,对Hg、Cr、N i污染进行单因子评价,制作了该地区土壤Hg、Cr、N i污染的预测表面,得到研究区土壤的分布图。研究表明,龙港区的土壤汞已达到了重度污染的水平,不再适合于农业生产。

Geographical information system （GIS） combined with Geostatistics was applied to evaluate the spatial distribution and variability of Hg, Cr and Ni of soil in the Lianshan and Longgang districts. The results showed that the theoretical semivariogram models of soil Hg, Cr and Ni were best described with a spherical model. The ratio of nugget to sill for was 56.6%, indicating that the spatial correlation of Ni was moderately dependent. The ratio of nugget to sill for Cr and Hg was 5.8%, indicating that the spatial correlation of the two heavy metals was strongly dependent. From the spatial distribution map of soil we could get the contamination index in the region, which indicated that the soil of Longgang country had been contaminated heavily and was unsuitable for agricultural use.