Effect of environmental factors on accumulation of trace metal in a typical shale gas exploitation area: A comprehensive investigation by empirical and geodetector models

Abstract Whether a certain relationship is exist between shale gas exploitation and accumulation of trace metals in soil is a controversial issue in recent years. To date, few study clearly reveal the intrinsic correlations between environmental factors and accumulation of trace metals in soil of shale gas exploitation area. This study investigated the content and pollution level of trace metals in a typical shale gas exploitation area, and the relationships between environmental factors and spatial distribution of trace metals were evaluated. The results showed that there were 10.33%-25.87% proportion of soils were considered as pollution by trace metals, and the content of Ba contributed the most to the pollution index ( P n ). Although SOM and CEC were considered as dominant factor influencing the content of trace metals, the results of MLR model based on natural factors strengthen the need for considering anthropogenic factors. Furthermore, the interaction between natural and ananthropogenic factors showed a siginifacnt nonlinear enhancement effect on accumulation of Cr, Ba and Sr, and the highest value of explanatory power ( q ) was 0.38 for SOM and distance. This study proved that the potential metal contamination was related to shale gas exploitation and provide reference for controlling soil pollution in shale gas exploitation area and making management strategy.