Development and testing of an integrated APEX-SWAT-GW model for simulations of agro-hydrological processes in a groundwater-fed plain in China

Groundwater depletion due to irrigation pumping in major food-producing regions has become a global concern. There is a need to establish a useful tool that can simulate the Soil-Plant-Atmosphere-Groundwater Continuum (SPAGC) system to evaluate various water-saving measures and agronomic practices for groundwater conservation and food security. This study developed an integrated APEX-SWAT-GW model, that could make full use of the advantages of APEX and SWAT-GW. The APEX-SWAT-GW model is applied to a representative groundwater overexploited area (22,753 km2) in the North China Plain (NCP). Good agreements were obtained in simulated results of wheat and maize yields, evapotranspiration (ET), and groundwater table depth in comparison with statistical data, remote sensing data, and monitoring well data. By testing simulations of water-limited irrigation and sprinkler irrigation, the model was found to be a useful tool for simulating agro-hydrological processes in areas where groundwater is over-exploited and selecting alternative irrigation management practices.