Modeling and Assessing Regional Agro-hydrological Response to Water Saving Managements in an Arid Irrigated Catchment with Shallow Groundwater

Water saving managements (WSMs) is important for maintaining the water resources sustainability in arid region, while WSMs influence the agro-hydrological process in arid irrigated catchments. In this study, the Hetao Irrigation District (Hetao) located in the upper Yellow River basin, was selected as the case study area. We have recorded the existing agricultural managements and accordingly set the WSMs scenarios (described the irrigation allocation reduction and the decreased groundwater storage). These scenarios were fed to an enhanced hydrological model (SWAT-AG), which based on the framework of the SWAT with significant improvements on describing the interactions of the vadose zone water, groundwater, salt and plant growth. The simulation results include the soil water/salt dynamic, groundwater fluctuation and crop growth. Result under baseline scenario revealed that the shallow groundwater and capillary rise are important for the crops growth and natural eco-system sustainability. Results under WSMs scenario were compared to show the water saving potential and the impacts of WSMs. Our study quantitatively described the response of the agro-hydrological process to WSMs and provided useful information for agricultural management in arid irrigated region.