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Given the typical disturbances in the aqueous environment in the alpine area because of mining activities in Northwest China, a case study highlighting the enhanced effect of mining dust diffusion on the melting of the adjacent glacier is presented here. Initially, a three-dimensional numerical model of the local airflow field was established by considering the effects of both mines and glaciers using the FLUENT software. Then, the diffusion path and size range of dust particles from the mines were simulated by feeding the mining dust parameters into the above numerical model. Finally, a physical simulation experiment was performed to evaluate the influence of mining dust coverage on the glaciers. The major conclusions of this study were as follows: (1) The local airflow field in the target alpine area is controlled by the ‘heat and cold double-island effects’ formed by the mine and the glacier, and the wind circulation always takes place in a clockwise direction between the mining pit on the left and the glacier on the right. (2) In a given airflow field, there is a spread of mining dust from the mine to the glacier along the upper airflow. The arrival rates of the dust are 16.9% and 13.3% in winter and summer, respectively, and the horizontal distance of dust diffusion is inversely proportional to its particle size. (3) For an ice sample with a sectional area of 225 cm2 and a volume of 1000 mL, the melting rate increased by 4.5 mL/h with an increase of dust coverage by 10%. Furthermore, when compared with a control group without dust cover, the effect of a 28% increase in dust coverage is approximately equivalent to the effect of a 1 °C increase in temperature on the ablation speed of the glacier. The study results can provide a useful reference for the selection of mining sites and the control of mining dust diffusion in alpine regions with glaciers, thereby facilitating environmentally friendly mining in alpine regions.

Glaciers, known as solid reservoirs, are important water supply sources in northwest China. In this paper, mineral dust collected from a Chinese alpine mining area (Beizhan iron mine) and an ice cube (with a 225 cm2 section and a volume of 1000 mL) were employed via a delicate physical experiment to study the ablation of glaciers covered by mineral dust in alpine regions. After that, the ablation mechanism was revealed using the energy conservation theory. The main findings are as follows: (1) When the solar radiation intensity is 993 W/m2, the glacier ablation rate increases by 13.9% (from 282 to 321.2 mL/h) as the mineral dust coverage rate increases from 0% to 42.7%. (2) When the mineral dust coverage rate remains at 30%, the glacier ablation rate increases by 11.6% (from 291.8 to 325.78 mL/h) as the solar radiation intensity increases from 1007 to 1153 W/m2. (3) When the solar radiation intensity and mineral dust coverage rate remain unchanged, the ablation rate of the glacier covered by the mineral dust inversely increases with the dust particle size. The ablation rates of the particle size gradings C, B, and A (the dust particle sizes of gradings A, B, and C in 0.0375–0.075 mm, 0.075–0.125 mm, and 0.125–0.25 mm accounted for 5%:50%:45%, 30%:40%:30%, and 70%:30%:0%, respectively) were 293.4, 301.2, and 305.6 mL /h, respectively, and the corresponding ablation rates increased by 2.7% and 1.5%. (4) The smaller the average particle size of the mineral dust, the greater the contribution to the ablation rate; a 1 °C temperature increase to the glacier ablation rate is equivalent to 29.1%, 33.6%, and 40.6% increases in dust coverage for particle size classes C, B, and A. (5) The mineral dust covering the glacier surface could not only reduce the reflectivity of the glacier surface to solar radiation but could also continuously transfer the absorbed radiant energy and its own chemical energy to the glacier body, accelerating the glacier’s meltwater speed. The findings of this paper can provide the necessary theoretical basis for mineral dust control and glacier water conservation in alpine mining areas.

Constructing reservoirs can make more efficient use of water resources for human society. However, the negative impacts of these projects on the environment are often ignored. Optimal reoperation of reservoirs, which considers not only in socio-economic values but also environmental benefits, is increasingly important. A model of optimal reoperation of multi-reservoirs for integrated watershed management with multiple benefits was proposed to alleviate the conflict between water use and environmental deterioration. The social, economic, water quality and ecological benefits were respectively taken into account as the scheduling objectives and quantified according to economic models. River minimum ecological flows and reservoir water levels based on flood control were taken as key constraint conditions. Feasible search discrete differential dynamic programming (FS-DDDP) was used to run the model. The proposed model was used in the upstream of the Nanpan River, to quantitatively evaluate the difference between optimal reoperation and routine operation. The results indicated that the reoperation could significantly increase the water quality benefit and have a minor effect on the benefits of power generation and irrigation under different hydrological years. The model can be readily adapted to other multi-reservoir systems for water resources management.