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Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Graphical abstract Highlights • The appropriate parameters of the SaltMod model were calibrated and validated. • The appropriate water management strategies were proposed. • Irrigation and drainage measures played a significant role in controlling salinity. • Results indicate that the proposed model is useful for soil salinity modeling. Abstract Soil salinity is considered the most serious factor that limits food security and sustainable development of irrigated agriculture productivity, especially in arid and semi-arid regions. Irrigation and drainage management play a critical role in soil water dynamics, soil desalinization, and crop growth and yield. This study was conducted to determine the changes caused by salinization on cultivated lands and salt wastelands in the long term given the present irrigation and drainage practices and under the different water management scenarios. Moreover, this study was aimed at developing appropriate management strategies to decrease the salt accumulation based on long-term simulation results. A SaltMod model was calibrated and validated using data from 2010 to 2016. Leaching efficiencies of F lr = 0.85 and F lx = 0.65 in the root and transition zones and natural drainage of 0.10 m/year were determined, thereby providing the optimal match between the observed and simulated values. Prediction results showed that the salinity of the cultivated land would exhibit slight decrease in the next 10 years under the current irrigation and drainage conditions. The proposed irrigation schemes were analyzed to improve the soil desalination effect in the long-term. Results indicated that autumn irrigation water was increased by approximately 10%–20%, and summer irrigation water was decreased by approximately 15% in the prospective 10 years (2016–2026) based on the present irrigation conditions. Furthermore, the soil salinity will decrease by approximately 1.06%–10.92%, and the total irrigation water will decrease by approximately 50–295 m3/ha, thereby possibly contributing to improved water saving and soil desalination. [ABSTRACT FROM AUTHOR]

The water movement research in irrigation districts is important for food production. Many hydrological models have been proposed to simulate the water movement on the regional scale, yet few of them have comprehensively considered processes in the irrigation districts. A novel physically based distributed model, the Irrigation Districts Model (IDM), was constructed in this study to address this problem. The model combined the 1D canal and ditch flow, the 1D soil water movement, the 2D groundwater movement, and the water interactions among these processes. It was calibrated and verified with two-year experimental data from Shahaoqu Sub-Irrigation Area in Hetao Irrigation District. The overall water balance error is 2.9% and 1.6% for the two years, respectively. The Nash–Sutcliffe efficiency coefficient (NSE) of water table depth and soil water content is 0.72 and 0.64 in the calibration year and 0.68 and 0.64 in the verification year. The results show good correspondence between the simulation and observation. It is practicable to apply the model in water movement research of irrigation districts. [ABSTRACT FROM AUTHOR]