The Effects of Planting Structure on Groundwater Depletion and Optimization Strategies in the North China Plain

Abstract Planting structure drive agricultural water use and is critical to groundwater depletion in the North China Plain (NCP). However, the effects of planting structure changes on groundwater depletion are rarely quantified, and severely depleted areas are often overlooked in previous planting structure optimization studies. This study developed a groundwater stress index (GWSI) to assess current groundwater drought and future risks and identify high groundwater stress zones (HGSZ). Groundwater depletion was estimated by integrating land surface model and AquaCrop outputs. A structural equation model was developed to assess the effects of planting structure to groundwater depletion, and a GWSI‐based optimization model was proposed to alleviate groundwater depletion, particularly in HGSZ. Results identified an HGSZ near the Henan–Hebei border, where the groundwater decline rate (−21.90 mm/year) was more than twice the NCP average (−8.73 mm/year). Under present planting structures, groundwater use remained unsustainable, with annual consumption exceeding recharge by 46.53 mm/year across the NCP and 97.09 mm/year in the HGSZ. Depletion was primarily affected by the planting area and spatial dispersion of winter wheat. Planting area expansion mitigated the effect of spatial redistribution on groundwater depletion, and it varied by crop. The optimization model reduced net groundwater depletion by 30.61 mm/year in the NCP and 63.23 mm/year in the HGSZ. The results highlighted the need to adjust planting structures, and revealed the effects to groundwater depletion, and demonstrated that partially converting rotation areas to single‐season cropping and shifting the rest southeastward effectively alleviated groundwater depletion. These findings provided an evidence base for designing region‐specific groundwater‐resource management strategies in the NCP.