A Simulation-Based Optimization Model for Control of Soil Salinization in the Hetao Irrigation District, Northwest China

Abstract

The average annual water diversion of the Hetao Irrigation District (HID) from the Yellow River is 4.5 billion cubic meters, mainly used for surface irrigation. Because the groundwater depth is shallow, strong evaporation conditions and unmatched irrigation conditions lead to serious soil salinization in the area; thus, the irrigation area’s ecological environment is fragile. Based on the current situation of the Yellow River irrigation project in the area, an interval two-stage robust stochastic optimization model is proposed to address the problem. In 2015, the Shuguang Experimental Station in the middle of the HID, Inner Mongolia, discussed the impact of different degrees of water–salt coordinated regulation on water consumption, yield and price of wheat, maize and sunflower under drip irrigation conditions. The obtained results provide the water shortage and water distribution targets of multiple water sources and multiple water levels in five irrigation areas of the HID. Those water distribution targets were used as the main input parameter and entered into the SALTMOD model based on the principle of water and salt balance. The output included data on groundwater mineralization and groundwater depth. It was observed that (1) integrated interval two-stage robust stochastic programming and the SALTMOD Model to couple optimization model under uncertainty can simulate a model together; (2) systemic risk issues were considered; and (3) the proposed method can be applied to the HID in northwest China to solve the soil salinization control problem. This approach is applicable to arid and semiarid regions that face similar problems.