You et al. (2025) Growth in agricultural water demand aggravates water supply-demand risk in arid Northwest China: more a result of anthropogenic activities than climate change

Identification

• Journal: Hydrology and earth system sciences
• Year: 2025
• Date: 2025-11-18
• Authors: Yang You, Pingan Jiang, Yakun Wang, Wenè Wang, Dianyu Chen, Xiaotao Hu
• DOI: 10.5194/hess-29-6373-2025

Research Groups

• Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling, China
• Xinjiang Agricultural University, Urumuqi, China

Short Summary

This study quantifies water supply-demand risks in the arid Tailan River Basin under 24 climate-land change scenarios, revealing that continuous agricultural expansion and the resulting surge in irrigation demand are the primary drivers of increasing water scarcity and risk, rather than climate change.

Objective

• To determine land change trends under six development scenarios and identify high-contribution factors driving these changes.
• To clarify the dynamics of water supply and demand under 24 land-climate combination scenarios and analyze their key drivers.
• To quantify water supply-demand risks under these land-climate patterns and identify the main influencing factors.

Study Configuration

• Spatial Scale: Tailan River Basin (TRB), an inland river basin in arid Northwest China, covering an area of 4218 km².
• Temporal Scale: Analysis and projections for the period 2020–2050, with historical data from 2000–2020 and future climate data extending to 2100.

Methodology and Data

• Models used:
  • PLUS (Patch-generating Land Use Simulation) model: For land use change prediction and driver analysis.
  • InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) model (Water Yield module): For water supply forecasting based on the Budyko framework.
• Data sources:
  • Land Use Data: RESDC (https://www.resdc.cn/), derived from Landsat MSS, TM/ETM, and Landsat 8 images.
  • Future Climate Data: TPDC (https://www.tpdc.ac.cn/), from the Coupled Model Intercomparison Project (CMIP6) using the MRI-ESM2.0 model, under SSP119, SSP245, and SSP585 scenarios.
  • Socio-economic Data: WorldPop (https://hub.worldpop.org), Aksu Prefecture National Economic and Social Development Statistical Bulletin, Aksu Prefecture Territorial Spatial Plan, Xinjiang Uygur Autonomous Region Territorial Spatial Plan, Xinjiang Uygur Autonomous Region Water Resources Bulletin, Wensu County and Aksu City Statistical Yearbooks.
  • Topographic Data: Digital Elevation Model (DEM) from https://www.gscloud.cn/.
  • Soil Data: FAO (https://www.fao.org/) for soil type and plant available water content, Yan et al. (2020) for root restriction layer depth.
  • Vegetation Data: Normalized Difference Vegetation Index (NDVI) from RESDC.
  • Spatial Resolution: All datasets harmonized to 30 m resolution.

Main Results

• Land Use Change: Cultivated land area is projected to expand significantly (average increase of 524.87 km²), while grassland area is expected to degrade (average reduction of 535.36 km²) from 2020 to 2050. Under the Balanced Economic and Ecological Development Scenario (BES), an additional 531.2 km² of cultivated land could be developed by 2050. Population is identified as the core driving factor for the evolution of most land types.
• Water Supply Dynamics: Climate change, particularly precipitation, has a more pronounced influence on water supply than land use changes. Water supply in the TRB is projected to fluctuate between 2.53 × 10⁷ m³ and 1.62 × 10⁸ m³ under different climate scenarios relative to the Natural Increase Scenario (NIS) baseline.
• Water Demand Dynamics: Human activities, especially land use changes, exert a more substantial influence on water demand than climate change. Water demand is projected to fluctuate between 1.887 × 10⁸ m³ and 5.316 × 10⁸ m³ under different climate scenarios relative to the NIS baseline. Agricultural irrigation consistently accounts for over 70 % of the total water demand across all scenarios, with its total volume continuously increasing.
• Water Supply-Demand Gap and Risks: Under the BES, the minimum water demand is projected to reach 4.87 × 10⁸ m³, while the maximum regional water supply is only 0.16 × 10⁸ m³, leading to a significant supply-demand gap exceeding 4.71 × 10⁸ m³. By 2050, the entire TRB is predicted to face a water supply-demand crisis, with at least 46 % of the area experiencing severe (Level III) or higher risks, including no less than 10 % at critically endangered (Level II) risk.
• Primary Driver of Risk: Continuous cultivated land expansion driven by agricultural activities, which drastically increases irrigation water demand, is identified as the root cause of intensifying water supply-demand conflicts and high risks in the TRB.

Contributions

• Systematically evaluates the combined impacts of multi-scenario climate and land use changes on water supply-demand patterns and associated risks in a typical arid basin, addressing a gap in literature that often focuses on unilateral impacts.
• Provides a scientific basis for optimizing regional water-land resource allocation and promoting agro-ecological sustainable development in arid regions.
• Establishes a comprehensive water supply-demand risk assessment framework integrating PLUS and InVEST models under 24 climate-land change scenarios.

Funding

• Major Science and Technology Project of Xinjiang Autonomous Region (2023A02002-1)
• Key Research and Development Plan of Shaanxi Province (2023-YBNY-270)

Citation

@article{You2025Growth,
  author = {You, Yang and Jiang, Pingan and Wang, Yakun and Wang, Wenè and Chen, Dianyu and Hu, Xiaotao},
  title = {Growth in agricultural water demand aggravates water supply-demand risk in arid Northwest China: more a result of anthropogenic activities than climate change},
  journal = {Hydrology and earth system sciences},
  year = {2025},
  doi = {10.5194/hess-29-6373-2025},
  url = {https://doi.org/10.5194/hess-29-6373-2025}
}