Effects of multi-factors on the spatiotemporal variations of deep confined groundwater in coal mining regions, North China

Hydrochemical Characterization and Quality Assessment of Groundwater in the Southern Plain of Hebei Province, China

“…This also confirmed the conclusions in Figure 7 above. The molar ratios of Ca 2+ and SO4 2− (Figure 9b) revealed that most groundwater samples plotted along a 1:1 line, implying SO4 2− and Ca 2+ in phreatic and confined groundwaters are probably sourced from the dissolution of sulfate minerals (gypsum (13) and anhydrite ( 14)). Some phreatic groundwater samples were observed above the 1:1 line (Figure 9b), suggesting that there may be other sources of SO4 2− in the Ion ratios are useful to improve understanding in depth of hydrogeochemical processes in groundwater [42] Most of the water samples were observed below the 1:1 line (Figure 9a), indicating that Na + concentrations in both aquifers are excessive relative to the Cl − content, besides, halite dissolution (10), ion-exchange (11) and silicate-dissolution (12) processes are also material sources of Na + in groundwater.…”

“…This also confirmed the conclusions in Figure 7 above. The molar ratios of Ca 2+ and SO 4 2− (Figure 9b) revealed that most groundwater samples plotted along a 1:1 line, implying SO 4 2− and Ca 2+ in phreatic and confined groundwaters are probably sourced from the dissolution of sulfate minerals (gypsum (13) and anhydrite ( 14)). Some phreatic groundwater samples were observed above the 1:1 line (Figure 9b), suggesting that there may be other sources of SO 4 2− in the phreatic aquifer besides dissolved sulfate minerals [43].…”

“…Hydrogeochemical research is the theoretical basis for realizing the rational utilization of groundwater resources and the effective protection of the groundwater environment, which can reveal the influence and relationship of various hydrogeochemical effects and anthropogenic activities on various geological phenomena during the formation of groundwater [13,14]. Further understanding the hydrochemical characteristics and quality status of groundwater resources is essential to help people select suitable water sources, formulate scientific water management policies and prevent groundwater pollution [15,16].…”

Deep Groundwater Flow Patterns Induced by Mine Water Injection Activity

“…As stated in the introduction, the high frequency coal mining activities in Jurassic Formation have induced a large amount of groundwater to be overexploited and drained to the surface. Due to the little rainfall and arid environment, increased groundwater depletion resulting from mining activity leads to water scarcity and adverse ecological impacts on the coal mining claims [ 22 ]. According to the statistical data, 1.2 billion tons coal was mined out in 2021 and 2.5 billion cubic meters of groundwater was pumped.…”

Statistical analyses of hydrochemistry in multi-aquifers of the Pansan coalmine, Huainan coalfield, China: implications for water-rock interaction and hydraulic connection

“…As reported by National Bureau of Statistics of China, coal accounts for 56.8% of total energy consumption in 2020. In recent years, inrush water has become an increasing threat to coal production because of the gradual increase in mining depth [ 3 ]. Most practices have proven that quickly and accurately identifying the source of the inrush water and then implementing countermeasures is the key to minimize the loss [ 4 ].…”