Analysis of the spatial relationship between heavy metals in soil and human activities based on landscape geochemical interpretation

Abstract

The development and formation of chemical elements in soil are affected not only by parent material, climate, biology and topology factors, but also by human activities. The pollution sources of heavy metals in the environment are mainly derived from anthropogenic sources, and heavy metal elements in soil have been considered to be powerful tracers for monitoring the impacts of human activities. The present study attempts to analyze whether and how a connection can be made between macroscopical control and microcosmic analysis, to estimate the impacts of human activities on heavy metals in soil, and to determine a way to describe the spatial relationship between heavy metals in soil and human activities, by means of landscape geochemical theories and methods. In addition, the disturbances of human activities on Zn, Cr, Cu, Pb, Hg, Cd, Ni and Ag are explored through the analysis of the spatial relationship between human disturbed landscapes and element anomalies, thereby determining the diversified rules of the effects. The study results show that the rules of different landscapes influencing heavy metal elements are diversified, and that the Zn, Ni, Pb, Hg and Ag elements are closely related with city landscapes, but Cu and Cd are not significantly affected by city landscapes; furthermore, the elements Ni, Pb, Hg, Ag and Cd are shown to be closely related with river landscapes, while evidently Zn is not affected by river landscapes; the relationships between mine landscapes and the elements Cr, Cu, Pb, Ni and Hg are apparent, among which Zn is not included; the relationships between the elements Zn, Cr, Cu, Pb, Hg, Cd, Ni and Ag and road landscapes are quite close, which shows that road landscapes have significant effects on these elements. Therefore, the conclusion is drawn that the response mechanism analysis of human disturbance and soil chemical element aggregation is feasible, based on the landscape geochemical theories and methods. The results of the study provide the possibility for applying spatial information techniques, such as remote sensing and geographic information systems, to study chemical elements in soil, thereby realizing the effective combination of macroscopic spatial information and microscopic mechanism of soil element migration research.