Distribution Characteristics and Risk Assessment of Soil Heavy Metal in Karst Peri-urban Areas in Guanshan Lake District, Guiyang City

PurposeTo study the distribution of heavy metals in the soil of peri-urban areas in karst area, providing scientific basis for the safe use of land resources.

MethodsThe peri-urban area of Guanshan Lake District in Guiyang City was selected as the study area. Soil samples were collected to detect and analysis the contents of five heavy metals: Cd, Hg, As, Pb and Cr in soil. Risk assessment was adopted through single factor evaluation, Nemerow comprehensive evaluation and potential ecological risk index evaluation method. Kriging interpolation method was adopted to study the spatial distribution characteristics.

ResultsSingle factor evaluation result showed that the pollution degree of elements in the study area was as followed Cd<As<Pb<Cr<Hg. Nemerow comprehensive evaluation result showed that the soil heavy metal pollution level in this area was heavy pollution. The risk degree of elements in potential ecological risk index result showed that: Cr<Pb<As<Cd<Hg, and the comprehensive potential risk was medium level. The distribution of Hg, As and Pb content were low in the middle and high around the area, and the distribution of Cd and Cr content were zonal transition.

ConclusionThe spatial distribution of heavy metals in karst peri-urbanl area are different. The soil in the study area was polluted by a variety of heavy metals, which had a medium degree of potential ecological risk.