Simulation of water and salt transport of uncultivated land in Hetao Irrigation District in Inner Mongolia

Water and salt transport was studied in the uncultivated land of Hetao Irrigation District in Inner Mongolia.Based on field experiment, mechanism of water and salt transport of the uncultivated land in the irrigation district was analyzed, and its water and salt transport dynamics were simulated with HYDRUS-1D model. The uncultivated land in the irrigation district had become salt storage area and the important regulator for water and salt balance in the irrigation district, and study on water and salt dynamic in uncultivated land was of significance for uncultivated irrigation district. The results showed that strong evaporation was the driving force for water and salt transport, EC values in soil layers of 5 cm had increased by 66.10%, and EC values in soil layers of 20 cm had increased by 63.89%. The uncultivated land underwent salt accumulating process in crop growing period but salt losing process in autumn irrigation period. Verification using the experiment data indicated that HYDRUS-1D model had a high precision for the simulation of water and salt transport of the uncultivated land in vertical direction. The results can serve as a scientific basis for regional water and salt management and sustainable development of the irrigation districts.