Xu et al. (2025) From grain to ground: How hydrologic uncertainty drives shifts in crop patterns across the Yellow River Basin

Identification

• Journal: Agricultural Water Management
• Year: 2025
• Date: 2025-12-08
• Authors: Zhongwen Xu, Shiqi Tan
• DOI: 10.1016/j.agwat.2025.110058

Research Groups

• College of Economics and Management, Nanjing Forestry University, Nanjing, China
• Business School, Sichuan University, Chengdu, China
• Graduate School of Engineering, The University of Tokyo, Tokyo, Japan

Short Summary

This study developed a robust bi-objective optimization model to optimize agricultural resource allocation in the Yellow River Basin under hydrologic uncertainty, finding that adaptive crop patterns and irrigation technology are crucial for balancing water use efficiency and inter-provincial fairness.

Objective

• To develop a robust bi-objective optimization model for the joint allocation of water and cultivated land resources within the land-water-food nexus, explicitly incorporating surface water availability uncertainty. The model aims to enhance agricultural water-use efficiency while simultaneously ensuring minimum crop production, sustainable land-use outcomes, and inter-provincial fairness in the Yellow River Basin.

Study Configuration

• Spatial Scale: Yellow River Basin, China (covering nine provinces).
• Temporal Scale: Mean values of indicators from 2010 to 2019.

Methodology and Data

• Models used: Robust bi-objective optimization model, Non-dominated Sorting Genetic Algorithm II (NSGA-II) for multi-objective optimization, implemented in MATLAB using the Global Optimization Toolbox.
• Data sources: Yellow River Water Resources Bulletin, National Bureau of Statistics database, China Urban Food Waste Report 2021. Data included surface water quantity, groundwater quantity, water consumption by various sectors, population, crop planting area, crop yield per unit area, minimum per capita annual grain demand, water quotas for irrigated areas, cultivated areas, and unit irrigated areas for nine provinces and three crops (paddy, wheat, maize).

Main Results

• Optimal planting patterns exhibit significant regional variation to balance efficiency and equity, with maize and wheat dominating and paddy rice being minimal or absent in water-scarce regions.
• Under scenarios of 10–30 % water reduction (low to high uncertainty), water-intensive paddy areas decrease by up to 15 % (e.g., Sichuan's paddy area reduces from 2.10 million hectares to 1.88–1.91 million hectares), while wheat and maize areas expand by 5–12 %, particularly in arid regions (e.g., Ningxia's wheat area increases from 0.10 million hectares to over 0.19 million hectares under high uncertainty).
• Increasing risk-awareness (robustness coefficient Γ from 0 to 0.8) marginally reduces overall water-use efficiency (from 3.13 kg/m³ to 3.10 kg/m³) but significantly enhances inter-provincial fairness (index increases from 0.74 to 0.87).
• Improvements in irrigation technology (e.g., a 5 % reduction in crop irrigation quotas) substantially enhance agricultural water use efficiency (from 3.28 kg/m³ to 3.89 kg/m³) and fairness (from 0.77 to 0.89), leading to a reduction in agricultural water consumption by up to 10.32 billion cubic meters.
• Despite water constraints, the total grain planting area remains stable, decreasing only slightly from 3.02 million hectares to 3.00 million hectares, indicating that efficiency gains enable stable food production within existing land limits.

Contributions

• Integration of hydrologic uncertainty into a basin-scale land-water-food nexus optimization framework using robust uncertainty sets, providing a more realistic and resilient representation of the system compared to deterministic or stochastic approaches.
• Development of a novel bi-objective robust optimization model that jointly maximizes irrigation water-use efficiency and minimizes inter-provincial inequality, explicitly quantifying trade-offs under varying uncertainty levels.
• Application of the model to the Yellow River Basin to generate region-specific adaptation strategies, including evaluating the effectiveness of technological improvements in irrigation for achieving efficiency and equity.
• Quantitative validation of the model's effectiveness, demonstrating an increase in agricultural water use efficiency of 43.7–45.5 % compared to real-world scenarios.

Funding

• Key Project of System Science and Enterprise Development Research Center (Grant No. Xq24B05)
• Fundamental Research Funds for the Central Universities (Grant No. 2024ZY-SX16)
• Program of China Scholarship Council (Grant No. 202506240052)

Citation

@article{Xu2025From,
  author = {Xu, Zhongwen and Tan, Shiqi},
  title = {From grain to ground: How hydrologic uncertainty drives shifts in crop patterns across the Yellow River Basin},
  journal = {Agricultural Water Management},
  year = {2025},
  doi = {10.1016/j.agwat.2025.110058},
  url = {https://doi.org/10.1016/j.agwat.2025.110058}
}