Agricultural water consumption accounts for more than 90% of water resources in Central Asia (CA). However, notable uncertainties remain regarding future variations in both net irrigation water demand ( \({\text{IWD}}_{\text{net}}\) , mm) and actual irrigation water demand ( \({\text{IWD}}_{\text{actual}}\) , m3) for major crops, as well as the underlying drivers of these changes. These uncertainties pose significant challenges for sustainable water management practices in the region. This paper investigates future changes in \({\text{IWD}}_{\text{net}}\) and \({\text{IWD}}_{\text{actual}}\) for four primary crops: corn, cotton, rice, and winter wheat. Using the partial derivative method, we analyze the factors contributing to these changes. The results indicate that \({\text{IWD}}_{\text{net}}\) for corn, cotton, and rice is expected to increase by 20–40%, 5–20%, and 5–20%, respectively, primarily due to rising vapor pressure deficit (VPD). Conversely, \({\text{IWD}}_{\text{net}}\) for winter wheat is projected to decrease, particularly under the SSP126 scenario, due to an increase in effective precipitation ( \({\text{P}}_{\text{eff}}\) ). In terms of \({\text{IWD}}_{\text{actual}}\) , the dominant influencing factor is the crop-planted area, with winter wheat showing a significant decrease in \({\text{IWD}}_{\text{actual}}\) . Understanding these dynamics is crucial for effective agricultural water resources management in CA. This knowledge will support the development of strategies to ensure sustainable water use in the region.
