都柳江上游沿岸喀斯特地区土壤重金属污染特征及风险评价

采集都柳江上游沿岸喀斯特地区62个土壤样品，利用地累积指数法、潜在生态风险指数法、克里金插值方法综合研究Sb、Cd、As、Cr和Pb五种重金属元素累积污染特征和潜在生态风险。结果表明，研究区土壤中Sb和Cd元素平均含量分别超过贵州省土壤环境背景值4.085倍和1.876倍。空间分布上，Sb元素严重污染面积占研究区总面积37.87%，主要受区内赋矿层位望城坡组、尧梭组和鸡窝寨组的影响。而Cd元素轻度累积污染面积为59.76%，其与碳酸盐岩分布密切相关。研究区土壤重金属污染潜在生态风险属于低风险等级，但是Cd和Sb元素单项污染潜在生态风险概率较大，Cd污染最高概率风险地层主要是石牛栏组和邦寨组，而Sb污染最高概率风险地层为邦寨组、鸡窝寨组和独山组。因此，研究区应重点防控石牛栏组、邦寨组、鸡窝寨组和独山组土壤Cd与Sb污染的潜在生态风险。 

Pollution characteristics and risk assessment of heavy metals in soils along the upper reaches of the Duliu river

Sixty-two soil samples were collected from the karst area along the upper reaches of the Duliujiang river，Guizhou Province. The purpose was to study the cumulative pollution characteristics and spatial pattern of potential ecological risks of five heavy metals，Sb，Cd，As，Cr and Pb by comprehensive utilization of the geo-accumulation index，potential ecological risk index and Kriging interpolation methods. The results show that the average contents of Sb and Cd in the soil of the study area exceed the environmental background values of Guizhou Province by 4.085 times and 1.876 times，respectively.In terms of spatial distribution，the local serious pollution area of Sb element accounts for 37.87% of the total，which is mainly controlled by the distribution of Wangchengpo formation，Yaosuo formation and Jiwozhai formation，the ore-bearing strata in the area.However，the proportion of slightly accumulated pollution area of Cd element is 59.76%，and the distribution of carbonate rocks is the main influencing factor for its general enrichment.The potential ecological risk in the study area is of a low level，but the probability of single potential ecological risk with medium or above Cd and Sb is relatively high. The highest probability risk group of Cd is mainly distributed in the strata of Shiniulan formation and Bangzhai formation，while that of Sb is distributed in the strata of Bangzhai formation，Jiwozhai formation and Dushan formation.Therefore，special attention should be paid to the prevention and control of potential ecological risks of soil Cd and Sb in the strata of Shiniulan formation，Bangzhai formation，Jiwozhai formation and Dushan formation in karst areas.