Identification of the Main Factors Influencing Spatial Distribution of Regional Soil Heavy Metals.

Abstract: Identification of main factors influencing spatial distribution of soil heavy metals has provided important implications for further analysis of the causes of soil heavy metal pollution. However, few research focused on quantitative identification of main factors influencing spatial distribution of soil heavy metals. In the present study, a method was proposed and aimed to identify main factors influencing spatial distribution of soil heavy metals. Soil heavy metal concentrations were assigned to the attributes of environmental factors and the study area was divided into different regions according to the attributes of environmental factors in order to calculate the degree of variation of soil heavy metals of different regions. By comparing the degree of variation of heavy metals of different districts, the influencing degree of environmental factors was obtained and main factors that affected the spatial distribution of soil heavy metals were identified. Taking Beijing City as studying region, the results showed that spatial distribution of Cu and Zn concentrations were mainly influenced by artificial activities (industrial activities, atmospheric fallout, population distribution and land use), Cr and Ni concentrations were mainly affected by natural factors (soil parent material and soil type). However, spatial distribution of As, Cd and Pb concentrations were influenced by artificial and natural factors such as soil parent material, atmospheric fallout and soil type. Synergistic effect of industrial activities and atmospheric fallout had greater contribution to the spatial distribution of As, Cd, Cr, Cu and Pb concentrations, that of soil parent material and soil type had greater contribution to the spatial distribution of As, Cd, Cu, Pb and Zn concentrations, and synergistic effect of soil parent material and land use had greater contribution to the spatial distribution of Cr and Ni.