基于GIS技术的荔城平原区耕地土壤重金属污染程度及其风险评价

Heavy metal contamination in farm soils at Licheng Plainarea and its risk assessment based on GIS

在空间插值基础上，利用Hakanson潜在生态风险指数法，研究了荔城平原耕地土壤重金属的污染程度及其潜在生态风险。结果表明，研究区8种重金属中汞污染指数最高，综合污染指数均值为0．897，处于警戒线水平，但总体上较清洁；在重金属潜在生态危害指数中，汞危害系数较高，达到47．496，处于中度危害水平，其余重金属元素的潜在危害系数为0．362～12．058，均处于轻度危害水平；综合潜在风险指数介于27．742～127．344，均值为68．129，处于轻度危害；并利用GIS软件绘制出污染风险评价分区图。

The pollution on the farm land in Licheng plain area and its potential ecological risk caused by heavy metal contamination were studied based on the spatial interpolation. The result showed that the single highest pollution index of 8 heavy metals was Hg. The average combined pollution index of heavy metals on the farm land was 0. 897, at the warning level. However, the over-all soil condition was acceptable. Among the 8 heavy metals, Hg had the greatest index of potential ecological hazard, i. e. , 47. 496, which was at the medium hazard level. The indices for the other 7 elements ranged from 0. 362 to 12. 058, at the light hazard level. The combined index of potential pollution risk of heavy metals on the farmland was 27. 742 to 127. 344, averaging 68. 129, which is considered a low hazard. A soil quality classification for the area based on the pollution risk index by the GIS technology was presented.