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[Display omitted] • Ancient reservoir sediments can be used as a potential tool for reconstructing long-term history of human activity and water level. • Anthropogenic activities had significantly affected vegetation conditions in the western Guizhou Plateau since ∼ 1700 CE. • Human-modulated dramatic fluctuation in the water level can markedly change reservoir ecosystem. Knowledge of the responses of reservoir ecosystems to anthropogenic and climatic impacts on multi-centennial timescales is relatively poor, but is crucial for the management of numerous reservoirs in China. In this study, the history of an ancient reservoir system was reconstructed for the last ∼ 700 yr based on multiple dating methods (210Pb, 137Cs, and 14C) and geochemical data (e.g., the mass accumulation rates, loss-on-ignition values, total organic carbon, total nitrogen, total phosphorus contents, and stable carbon isotope ratios of organic matter) obtained for sediment cores from Gongqing Reservoir in Guizhou Province, southwestern China. Combined with historical literature and regional climatic records, the response of the aquatic ecosystem in Gongqing Reservoir to water level fluctuations, anthropogenic activity, and climatic changes during the last ∼ 700 yr was assessed. The results suggest that dramatic changes in the water level due to dam heightening in 1950 s significantly changed the aquatic ecosystem of Gongqing Reservoir. During periods of low water levels (average water depth = 1–2 m; 1345–1957 CE), aquatic macrophytes contributed more to the sedimentary organic matter, whereas phytoplankton increasingly contributed more during periods of high water levels (∼ 5 m; 1957–2020 CE). During the late stage (1700–1957 CE) of low water levels, the reservoir ecosystem was significantly affected by human activities. Combined with regional geological and historical records, we consider that increased population and enhanced human activities have markedly affected vegetation conditions in western Guizhou Province since ∼ 1700 CE. After 1957 CE, anthropogenic activities were key in affecting the aquatic ecosystem of Gongqing Reservoir. Especially in the last decade, large housing developments and enhanced agricultural activities in the watershed have led to enhanced catchment erosion and transport of more nutrients into the reservoir, thus promoting the algae productivity. These results provide new insights into how reservoir ecosystems respond to water level fluctuations, anthropogenic activity and climatic changes on multi-centennial timescales. [ABSTRACT FROM AUTHOR]

• Constructed a groundwater numerical model by Visual MODFLOW and studized the feasibility of mine water recharge to aquifers. • Analyzed the impact of mine water recharge on the water level and inflow of aquifers. • To ensure the safe mining in the future, the dynamic water inflow under different mining levels was predicted. Water inflow poses a critical safety concern in coal mining. The pressing challenge in current mine water inflow research is the need to enhance the prediction of dynamic changes in mine water inflow across different mining stages. In this study, the hydrogeological conditions and aquifer structural characteristics of the Wutongzhuang Coal Mine in Hebei Province, China were analyzed, and the results were combined with pumping test and drilling data. A numerical model of groundwater flow in the study area was established using Visual MODFLOW and the model was calibrated and verified by comparing its results with the measured values to ensure that it realistically reflected the state of groundwater movement in the study area. The results of numerical simulation indicated that: (1) The water level of the Ordovician aquifer varies significantly by season. A large exposed area of Ordovician limestone in the western mountainous region receives a large amount of rainfall infiltration recharge in the summer rainy period that raises the water level of the Ordovician aquifer in the study area. (2) The groundwater system in the study area is in an equilibrium state, with the water inflow approximately equal to the outflow. (3) The recharge of mine drainage water has a slight positive effect on the Ordovician water level and the floor water inflow, with the impact on the water level of the aquifer decreasing as the distance from the recharge well and the import of Ordovician limestone water increase. In cases in which there is mine water recharge, the water level of the Ordovician aquifer is approximately 0.33 to 1.37 m higher than in cases without recharge, resulting in an increase in water inflow of approximately 10.6 m3/d. (4) In cases in which there is recharge of all drainage water, the maximum water inflow into the fifth mining area is 3,491.3 m3/d, which is 12.5 m3/d higher than in the case without recharge. These results provide important technical references for the formulation of mining schemes and water prevention measures in mining areas. [ABSTRACT FROM AUTHOR]