广东省揭阳市土壤铅的空间分布特征及影响因素

以广东省揭阳市土壤为研究对象,采集了表层土壤(0~20 cm)样1 330个和深层土壤(>150 cm)样331个,测定了土壤Pb含量。利用GIS空间分析技术、半变异函数拟合和方差分析等方法研究土壤Pb含量的空间结构、特征和影响因素。结果显示: 揭阳市不存在明显的土壤Pb污染,表层土壤Pb含量平均值39.26 mg/kg,低于揭阳市土壤Pb背景值(43.71 mg/kg),略高于广东省土壤Pb背景值(36.00 mg/kg);富集因子表明研究区表层土壤Pb富集程度主要为无富集和轻微富集,分别占52.11%和42.63%,Pb富集不明显;研究区表层土壤Pb空间分布呈中等自相关性;表层土壤Pb高值区主要分布在人类活动影响强烈的东部和南部地区。按土地利用、成土母质、土壤类型及其理化性质的分类统计表明,林地及未利用地表层土壤Pb含量最高;页岩风化形成的土壤Pb含量显著高于其他成土母质区土壤;黄壤Pb含量相对较高;有机碳和pH值均与土壤Pb含量呈显著正相关。

Spatial Distribution Characteristics and Influencing Factors of Soil Lead in Jieyang City,Guangdong Province

Taking the soil in Jieyang City as the research object, 1,330 surface soil samples (0-20 cm) and 331 deep soil samples (>150 cm) were collected, and the Pb content in soil was determined. GIS spatial ana-lysis technology, semivariogram fitting and variance analysis were used to study the spatial structure, distribution characteristics and influencing factors of soil Pb content. The results showed that there was no obvious Pb pollution in Jieyang city, and the average Pb content in surface soil was 39.26 mg/kg, which was lower than the background value of Pb in Jieyang City (43.71 mg/kg) and slightly higher than that in Guangdong Province (36.00 mg/kg). Enrichment factors showed that the enrichment degree of Pb in the surface soil of the study area is mainly no enrichment and slight enrichment, accounting for 52.11% and 42.63%, respectively, and Pb enrichment is not significant; The spatial distribution of Pb in the surface soil of the study area showed mode-rate autocorrelation. The Pb high value areas of surface soil are mainly distributed in the eastern and southern parts where human activities have a strong influence. According to the classification statistics of land use, soil parent material, soil type and its physical and chemical properties, the Pb content in surface soil of woodland and unused land is the highest; The Pb content in the soil formed by shale weathering is significantly higher than that of other soil-forming parent materials; Pb content in yellow soil is relatively high; Organic carbon and pH were positively correlated with Pb content in soil.