Assessment of agricultural water-saving potential in arid regions based on an integrated sustainable management framework

Arid and semi-arid regions face multiple interrelated challenges, including water scarcity, soil salinization, and agricultural nonpoint source pollution. In addition, existing irrigation measures and management systems remain suboptimal, underscoring the need for sustainable irrigation management frameworks. In this study, an integrated sustainable management framework was developed to enhance water utilization coefficient while controlling soil salinity in arid regions. The framework couples a water-salt process simulation model with a multi-objective optimization algorithm (NSGA-II), using maximized economic benefits, minimized surface water diversion, and reduced agricultural nonpoint source nitrogen loads as optimization objectives. This integrated framework enables a systematic exploration of efficient water allocation strategies under different water-saving and salinity-control pathways. It also quantifies the maximum water-saving potential of the Hetao Irrigation District (HID), China. The results indicate that Yellow River water diversion to the HID can be reduced to 3.69 billion m³ . This can be achieved by limiting groundwater extraction to no more than 700 million m³ , improving the canal system water utilization coefficient, and prioritizing the adoption of water-saving irrigation technologies. Furthermore, optimization of the cropping structure can achieve a high-efficiency allocation with an economic water productivity of 2.41 yuan/m³ . This is achieved by increasing the share of salt-tolerant and water-efficient crops, ensuring a priority irrigation quota of 2386 m³ /ha for wheat, and optimizing sunflower irrigation to 1544 m³ /ha. The results also show that single water-saving measures have limited effectiveness and may introduce secondary environmental risks. An integrated, system-level strategy is therefore needed to address water scarcity and salinization constraints in arid irrigation districts. Overall, this study provides a robust scientific basis and a transferable technical framework for water resource optimization and agricultural green transformation in similar arid and semi-arid regions.