典型地震灾区农业土壤重金属分布特征与评价

在典型地震灾区彭州市通济镇新黄村选取29个农业土壤样品,其中水田土壤分层采样,研究土壤Cd、Cu、Pb、Zn空间分布特征和污染程度。结果表明:该村土壤重金属含量不等,由高到低依次为Zn、Cu、Pb、Cd。区域内耕地土壤平均重金属含量高于非耕地,安置点土壤重金属平均含量高于非安置点。水田土壤重金属含量随着土层深度增加,含量逐渐减少。在同一土层,安置点土壤重金属含量高于自然水田。土壤Cd为重污染,Cu为轻污染,Zn预警,未受Pb污染,其综合污染指数为Cd>Cu>Zn>Pb。34.48%样点受污染,绝大多数为冲积平原与丘陵交界处安置点水田土壤。

Distribution and Evaluation of Heavy Metals of Agricultural Soil in Typical Earthquake Disaster Area

Xinhuang village,Pengzhou city is a typical "5·12" earthquake disaster area,from which twenty-nine soil samples were chosen.Among these,soil profile of paddy field was sampled according to soil layers.The study was made mainly on space distribution and pollution evaluation of Cd,Cu,Pb,Zn.The content of heavy metals in the soil samples of this village was different,with the order being Zn>Cu>Pb>Cd.Average content of heavy metals of the farming soil was higher than that of the non-farming,and average content of heavy metals of the soil under settlement spot was higher than that of the non-settlement spot.Heavy metals content of the paddy field soil reduced gradually along with the soil layer deepening,and heavy metal content of the soil under settlement spot was higher than that of the natural paddy field in the identical soil layer.Soil Cd was the heavy pollution,Cu was the light pollution,Zn was the early warning,and Pb was not polluted.Sequence of soil comprehensive pollution index was Cd>Cu>Zn>Pb.34.48% of samples were polluted,most of which were sampled from paddy field under settlement spot.