AUTHORS: Shoujuan Li*, Lei Yang, Liding Chen, Fangkai Zhao, Long Sun – Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences
ABSTRACT: Rapid urbanization has significant influences on soil processes, especially for peri-urban areas. The complex land use pattern and intense human activities has significant influences on spatial distribution of heavy metals. Understanding the land use’s influence on spatial distribution of heavy metals in peri-urban soils is important for soil security and ecosystem services. In this study, a typical peri-urban catchment in east China was selected. Totally 3 transects along and perpendicular across the main river with 35 sampling sites were selected to identify the spatial distribution of heavy metals in peri-urban soils. The concentrations of Cu, Zn, Cd, Ni, As, Cr, Pb, and Hg in different soil depth were analyzed. The results the heavy metal concentration in soils were significant influenced by land use type. The farmland had the highest values and forestland had relatively lower values. The spatial variation of heavy metals showed that concentration of heavy metal rapidly increased when the town and village appeared. Spatial analysis showed the concentration of heavy metal increased with increasing percentage of town area in buffer zone. This indicated that land use structure determined the heavy metal concentrations in peri-urban soils, and the influence were correlated with scale and location of towns and villages. The concentration of Cu, Zn, Cd, Pb and Hg in soils were correlated with the altitude, distance from river, distance from town and village, and clay content. Interestingly, results also showed that the heavy metal in forestland that human could arrive were higher than forestland with no human activities, and historic land use still had affection on the concentration of heavy metal in forestland.