Hydrogeochemical and water cycle features of groundwater at a western arid coal mine in the Ordos Jurassic coal province, China

摘要

Xiaojihan coal mine, located in the east of the Ordos basin, is typical of the regional hydrogeologic background and it commenced coal mining in 2014. To investigate water quality and water cycle features, 21 water samples were collected from underground aquifers for water quality tests, 14 samples for isotopes of D/~(18)O and T tests, and 6 samples for ~(14)C tests. The characteristics of the Jurassic aquifers are neutral pH, enriched in Na~+, high concentration of SO_4~(2-), large TDS, and polluted with B and E It was drawn that coal mining was inducing a much higher water connected zone than as expected and coal mining was dewatering and increasingly enlaring the depression cone in the Jurassic aquifers. It is urgent to limit the maxmum height of water interconnneted zone and control the further expansion of depression cone in the Jurassic aquifers.