湖南矿区县域耕地重金属污染空间特征及潜在风险评价

运用单因子指数法和潜在生态危害指数法,借助GIS技术,对研究区耕地土壤Cd、Cr、Pb、As和Hg的污染状况进行了评价和预警。单因子指数评价结果显示,研究区各重金属的污染指数大小依次为CdAsHgCrPb;潜在生态风险评价结果显示,研究区各重金属单项潜在生态风险系数大小依次为:CdHgAsPbCr,其中八团乡和高垅镇的Cd污染风险相对较大;研究区耕地土壤重金属的综合潜在生态风险程度中等,各个乡镇的综合潜在生态风险指数从大到小依次为:高垅镇八团乡潞水镇思聪乡平水镇严塘镇秩堂镇腰陂镇火田镇洣江乡虎踞镇下东乡;综合潜在生态风险预警结果显示,巨警区主要集中在高垅镇、八团乡、潞水镇、平水镇、思聪乡以及桃坑乡。研究结果可为研究区域的重金属污染综合防控和农业安全生产布局提供科学依据。

Spatial Characteristics and Potential Risk Assessment of Heavy Metal Pollution in Farmland in Hunan Mining Area

The pollution status of Cd, Cr, Pb, As, and Hg in cultivated land in County was evaluated and analyzed by using the single factor index method and potential ecological risk index method, with the help of GIS technology. The results of single factor index showed that the pollution index of each heavy metal in the study area is Cd, As, Hg, Cr, Pb. The potential ecological risk assessment results indicated that the potential ecological risk coefficient of each heavy metal in the study area was Cd, Hg, As, Pb, Cr, and the risk of Cd pollution in the Batuan town and the Gaolong town was relatively large. The comprehensive ecological risk of heavy metals in the cultivated soil of County was moderate, its index of each township from high to low is Gaolong Town, Batuan Town, Lushui Town, Sicong Town, Pingshui Town, Zhitang Town, Yantang Town, Yaopi Town, Huotian Town, Mijiang Town, Huju Town, Xiadong Town; The results of the risk warning showed that the giant police areas are mainly concentrated in Gaolong town, Batuan Township, Lushui Town, Pingshui Town, Sicong Town and Taokeng Town. The results can provide a scientific basis for the comprehensive prevention and control of heavy metal pollution and the layout of agricultural safety production in the study area.