The medium and long-term demand prediction for water resources is critical to the country’s macro-allocation of water resources and the formulation of a long-term regional economic development strategy. However, the official prediction report of China’s water resources was created ten years ago, and its results are far from accurate in practice making it difficult to direct China’s water resource planning in the coming ten years. By introducing the demand forecasting method for the first time, this study built a mathematical prediction model that integrates “data constraint + mathematical prediction + actuarial prediction”. The conclusions are as follows: (1) The new method developed in this research is more accurate than previous prediction methods and has a higher degree of matching with actual data. Despite the problem of trend extrapolation, this model can accurately understand the long-term trend. However, the amount of data must be calculated. (2) China’s consumption of total water, agricultural water, industrial water, domestic water, and ecological water will predict to be 552.9 billion m³, 319.1 billion m³, 95.7 billion m³, 95.5 billion m³ and 42.6 billion m³ in 2030, respectively, as well as 504.7 billion m³, 281.1 billion m³, 61.4 billion m³, 101.4 billion m³, and 60.8 billion m³ in 2050, respectively, indicating obvious structural changes. (3) China’s industrial structure evolves frequently; therefore, water resource forecasting must account for changes in industrial structure as well as geographical variances. In North China, agricultural water demand will fall, but ecological water investment will rise. The planning and distribution of the nation’s water resources will significantly be influenced theoretically and practically by the development of this methodology study. This method is universal and can be used for long-term prediction of future water demand in other countries.

Research on control factors of coal deformation has great significance in guiding coal resource assessment and coal mining exploitation, prediction of coal gas outburst, evaluation on coalbed methane producibility. The deformation of coal and coal measure is controlled by the rock mass structures. This paper try to probes into the mechanism of coal deformation by theories and methods of rock mechanics and other new subjects, meanwhile, the effect degree of controlling factors on coal deformation are quantized. The conclusions have been verified by comparing the calculation results in several mining districts with different types. The results show that the factors which effect the coal deformation are the thickness of coal seam, the thickness of brittle and ductility rock stratum at a certain layer of coal seam roof and floor and the lithology of roof and floor of coal bed.

The workover operations are related to the efficiency of coalbed methane (CBM) and directly decide whether the CBM production target can be achieved. To reduce the damage to the coal reservoir caused by the workover duration, a series of experiments related to the damage to the coal seam by the workover duration, such as permeability experiment, stress–strain experiment, velocity sensitivity experiment, and stress sensitivity experiment, was carried out. The results show that the permeability of the coal sample increases first and then declines with the increase of the immersion time and the changed rate of coal samples is unbalanced. The permeability of the coal sample begins to decrease after 384 h of immersion. The mechanical properties of the coal sample did not change much when the water immersion time was short, but it showed a zigzag change when the water immersion time increased, and the stress–strain peak appeared earlier after 384 h of water immersion, and the elastic modulus became smaller. The consequences of stress sensitivity experiments show that the longer the immersion time, the weaker the recovery of permeability after pressure relief; especially after 384 h, the recovery of permeability is even weaker. Speed sensitivity test results show that the degree of damage to the sensitivity of the coal sample is moderate, but when the coal sample is immersed in water for more than 96 h, the permeability damage is generally greater than that of the dry coal sample. The experimental results prove that the effect of the workover duration has a significant impact on coal reservoir damage, and the workover duration is reasonably arranged. If we can make use of the phase characteristics of physical property changes of coal samples under different immersion times and complete the workover operation in the most appropriate time, then the coal reservoir can be well transformed, and it is possible to obtain good results. Both the production efficiency and production volume of CBM wells will increase.

Xinjiang is rich in coal resources, but the extremely shortage of water resource in some regions has significant impact on coal exploitation. Water is required in coal exploitation, as well as cleaning, utilization and upgrading of coal, so the shortage of water resource is impacting the fate of coal directly. Xinjiang area is the 14th coal base of our country, a foothold of the strategy of West-Development in China, and a support point of national strategic layout of the Belt and Road Initiative. If the problem of coal and water is solved, the problem of energy safety and nationality will be solved. Based on the comprehensive analysis of coal geological conditions and water resources conditions in Xinjiang, we have studied the spatial distribution relationship between coal resources and water resources in this paper, and find that the whole water resource is short in regions of Xinjiang with rich coal resource. In this paper, some feasible suggestions have been put forward to solve the problem of asymmetric distribution of water and coal resources as the key problem at present, in order to provide reference for departments of resource development and planning.

Workover operations significantly impact the service life and gas production capacity of coalbed methane (CBM) wells and are crucial for optimizing resource exploitation. To investigate workover operations’ impact on coal seam reservoirs, the authors designed a series of experiments and obtained the following results: (1) The workover operation induced a phase transition in the solid-liquid composition produced by the CBM well, indicating changes in the coal reservoir’s internal structure. (2) During the stable production stage before and after the workover, the proportion of Na⁺, Cl⁻, Ca²⁺, and Total Dissolved Solids (TDS) in the water samples showed a downward trend as a whole, while the HCO₃⁻; after the workover, the Na⁺, Cl⁻, Ca²⁺, and TDS all increased suddenly, while the HCO₃⁻ decreased. (3) While inorganic minerals predominated in the precipitation material during the stable production stage pre-workover, their proportion decreased post-workover, with a noticeable shift in their qualitative composition. (4) It is an indisputable fact that workover operations cause physical and chemical damage to coal seam reservoirs. During workover operation, how to avoid damage and conduct benign reconstruction to the reservoir will be the direction of our future efforts. The experimental results provide valuable insights that can guide the optimization of CBM workover operations and inform the strategic planning of subsequent drainage activities.

The ecological consequences of hydraulic engineering on riverine environments have intensified the need for scientifically grounded ecological flow regimes. To ensure habitat suitability during critical fish spawning periods, this study developed habitat preference curves by correlating physiological parameters with key hydro-environmental drivers. A habitat suitability index (HSI) model was established using fuzzy logic, integrated with a genetic algorithm (GA) to simultaneously optimize fuzzy membership functions and inference rules. This model was applied to simulate the relationship between the weighted usable area (WUA) and discharge for various fish egg types in the reach downstream of the Fengman Dam, ultimately facilitating the determination of an optimized ecological pulse flow hydrograph. The results reveal distinct hydro-environmental preference variations among species. Specifically, drifting eggs require specific hatching cycles supported by higher flow magnitudes and velocities. Conversely, adhesive eggs experience a significant reduction in suitable habitat area under high-flow and high-velocity conditions. These findings suggest that reservoir water resource allocation must be tailored to the life-history requirements of target species to maximize spawning success. This study provides a robust scientific framework for eco-friendly reservoir scheduling and the conservation of regulated river ecosystems.