Straw mulching is an effective agricultural technology to reduce soil water loss in arid and semi-arid areas. Herein, the soil temperature and soil water content of bare land (LD) and 5 cm (JG5), 10 cm (JG10), 15 cm (JG15), 20 cm (JG20) and 30 cm (JG30) straw mulch thicknesses were measured through field experiments performed to assess the soil water evaporation using the simultaneous heat and water model during a freeze–thaw period. The results showed that the inhibiting effect of straw mulching on soil water evaporation during the freeze-thaw period reached 24–56.7%, and straw mulch reduced the range of daily soil water evaporation by 2.02–2.48 mm, the effects of random factors on the daily soil water evaporation were significantly decreased. The highest soil water evaporation rate occurs during the unstable freezing stage, and the lowest occurs during the stable freezing stage. When the straw mulch thickness exceeded 10 cm, the effect of increasing straw mulch thickness on daily soil water evaporation was reduced. The straw mulch layer could not completely inhibit the effect of the external environment on soil water evaporation even when the straw mulch thickness was increased to 30 cm. This research results can provide a basis for the scientific evaluation and prevention of soil water evaporation in arid and semi-arid areas.

Reservoir sediment severely impacts water supply in water-scarce regions, making reservoir dredging an urgent global issue. The investment required for deep-water dredging far exceeds that for dry land dredging. Therefore, against the backdrop of the national water network construction, this study focuses on a typical inter-basin water transfer project in Northern China. To increase the proportion of dry land dredging volume and save costs, this study uses compensation reservoirs to replace the emptied reservoir in undertaking water supply tasks as a constraint. Single-objective optimization models for single reservoirs and multi-objective optimization models for reservoir groups are established, using game theory comprehensive subjective and objective weighting methods to select the optimal solution. The following conclusions are drawn from comparing the water supply effects under various emptying sequences: the optimal sequence for emptying reservoirs should be determined through precise quantitative analysis; as the dredging is completed, the water supply tends to stabilize; the satisfaction with the water supply and the variance of the water shortage rate are primarily related to reservoirs with a large inflow and storage capacity; dredging occurs according to the descending order of the storage capacity of reservoirs; and the startup proportion of pump stations shows an increasing trend.

At the request of the authors, the article ‘Optimization of water supply reservoir scheduling with insufficient regulating capacity’ has been withdrawn from Water Supply.