The spatial combination of stratigraphic structural elements significantly influences the overburden damage caused by mining. However, existing studies have not yet clearly revealed the specific relationship between these elements and overburden damage, nor have they intuitively demonstrated the spatial distribution characteristics of overburden damage. In response, this paper proposes a comprehensive analysis method that can visually and quantitatively characterize the spatial distribution of overburden damage. This method combines stratigraphic model generalization, damage mechanics modeling, numerical simulation, and color mapping characterization. This method was applied to analyze the mining damage characteristics of different structural overburdens in the Yushenfu mining area. The analysis revealed a prevalent stratigraphic combination pattern of sand layers, soil layers, and two sections of mudstone and fine sandstone interbeds. The study shows that mining height and bedrock-soil ratio are important stratigraphic structural factors that affect the fracture/mining height ratio. The ranking of elastic modulus loss and spatial loss in various damaged areas of the overburden is consistent, in the following order: collapse zone > fracture zone > bending subsidence zone. Furthermore, this method reveals the mechanism of increased residual expansion in the overburden caused by coal mining, which, in turn, leads to surface collapse. This method provides a theoretical basis for implementing targeted engineering disposal and safety measures.

In order to determine the current levels, spatial distribution patterns, and potential pollution of trace elements (TEs) in the atmosphere of the Tibetan Plateau (TP), snow pit samples were collected in May 2016 from five TP glaciers: Qiyi (QY), Hariqin (HRQ), Meikuang (MK), Yuzhufeng (YZF), and Xiao-dongkemadi (XDKMD). Concentrations of 13 TEs (Al, Ba, Cd, Co, Cr, Cu, Fe, Li, Pb, Sb, Sr, U, and Zn) in the snow were measured. The spatial distribution patterns and depth profiles of TEs from the studies sites revealed that the influence of dust on TEs was more significant on the MK and YZF glaciers than on the QY, HRQ, and XDKMD glaciers. The spatial distributions of TE EFFe values differed from their concentrations, however. The enrichment factor (EF) values and concentrations of some TEs in the YZF, QY, and XDKMD glaciers revealed that the pollution levels of these elements were significantly lower than those found in previous research. Examination based on EFs, principal component analysis, as well as the calculated non-dust contributions of TEs, revealed that dust was the principal source for most TEs in all five glaciers, while biomass burning was another potential natural source for TEs in some glaciers, such as QY. In contrast, Cd, Ba, Sr, Cu, Pb, Zn, and Sb were occasionally affected by anthropogenic sources such as road traffic emissions, fossil fuel combustion, and mining and smelting of nonferrous metals in and beyond the TP. Air mass backward trajectories revealed that potential pollutants were transported not only from local sources but also from Xinjiang Province in northwestern China, as well as South Asia, Central Asia, the Middle East, and Europe. (c) 2020 Elsevier Ltd. All rights reserved.