SHEN et al. (2026) Estimation of water savings from farmland fallowing in the tarim river basin under food security and ecological security constraints and threshold effects of driving factors

Identification

• Journal: Irrigation Science
• Year: 2026
• Date: 2026-03-14
• Authors: Liqiang SHEN, Jiaxin Hao, Chenglong Yao, Xinyu Du, Zengyi Cheng, Yuxuan Wang, Fulong Chen
• DOI: 10.1007/s00271-026-01108-2

Research Groups

• College of Urban and Environmental Sciences, Shihezi University, Shihezi, China
• Faculty of Geographical Science, Beijing Normal University, Beijing, China
• Xinjiang Production and Construction Corps Key Laboratory of Oasis Town and Mountain-Basin System Ecology, Shihezi, China
• College of Water Conservancy and Architectural Engineering, Shihezi University, Shihezi, China

Short Summary

This study developed a framework to estimate water savings from farmland fallowing (FLWC) in the Tarim River Basin under food and ecological security constraints. It found that suitable fallow areas and FLWC peaked in 2015, with cotton exhibiting the highest water-saving potential, and identified mean air temperature and mean relative humidity as primary climatic drivers with threshold effects on FLWC.

Objective

• To determine the scale of cropland that should be fallowed under the constraint of ensuring food security.
• To identify how fallow land should be rationally spatially allocated under the constraint of ecological security.
• To quantify the magnitude and spatial distribution of FLWC under the dual constraints of ecological and food security.
• To identify the effects of climatic factor variations on FLWC.

Study Configuration

• Spatial Scale: Tarim River Basin (TRB), Xinjiang Uygur Autonomous Region, China (75°06′–92°50′E, 36°30′–42°10′N).
• Temporal Scale: 2000 to 2020.

Methodology and Data

• Models used:
  • Farmland demand model (for suitable fallow area delineation)
  • GIS technology (for spatial analysis)
  • FAO-recommended Penman–Monteith model (for reference crop evapotranspiration, ET₀)
  • Crop coefficient method (for crop evapotranspiration, ETc)
  • United States Department of Agriculture Soil Conservation Service method (for effective precipitation, Pe)
  • Random Forest (RF) model (for identifying response relationships between climatic factors and FLWC)
• Data sources:
  • Meteorological data: National Climate Center of the China Meteorological Administration (interpolated using Inverse Distance Weighting).
  • Socioeconomic data: Xinjiang Uygur Autonomous Region Statistical Yearbook, China Population and Employment Statistical Yearbook, Statistical Communiqué on National Economic and Social Development of the Xinjiang Uygur Autonomous Region, Xinjiang Uygur Autonomous Region Department of Water Resources.
  • Crop distribution data (cotton, winter wheat, maize): Zenodo, Science Data Bank.
  • Farmland fallow urgency index (SILF) dataset: Derived from previous work by Shen et al. (2025).
  • Farmland area data: Data Center for Resources and Environmental Sciences, Chinese Academy of Sciences.

Main Results

• From 2000 to 2020, the suitable fallow area in the TRB first increased and then decreased, peaking in 2015 at 15,255.4 km² (37.42% of total farmland area), primarily distributed in marginal zones. By 2020, it declined to 8,120.12 km² (19.14%).
• Water savings from farmland fallowing (FLWC) for winter wheat, cotton, and maize varied significantly across growth stages, being relatively low during initial and late stages but higher during developing and middle stages. Spatially, FLWC generally increased from the basin periphery toward the central areas.
• The total FLWC for winter wheat and cotton peaked in 2015 at 1.01 × 10⁹ m³ and 5 × 10⁹ m³, respectively. Maize FLWC peaked in 2020 at 3.12 × 10⁷ m³. The overall FLWC was most significant in 2015, totaling 6.03 × 10⁹ m³.
• Cotton demonstrated the greatest water-saving potential (1472.104 m³), followed by winter wheat (1108.268 m³) and maize (706.331 m³).
• Mean air temperature (Atmp) was the primary driving factor for winter wheat and maize FLWC, exerting a positive effect. Mean relative humidity (Arhu) was the main limiting factor for cotton FLWC, showing a negative effect. These climatic factors exhibited threshold behaviors and interannual variability, indicating complex nonlinear responses.

Contributions

• Developed a novel estimation framework for water savings from farmland fallowing (FLWC) that integrates food security and ecological security constraints for arid regions.
• Provided a detailed spatiotemporal quantification of suitable fallow areas and associated water savings for major crops in the Tarim River Basin.
• Identified crop-specific primary climatic drivers (mean air temperature for winter wheat/maize, mean relative humidity for cotton) and revealed their complex nonlinear and threshold effects on FLWC.
• Offered scientific insights for implementing "precision fallowing" and dynamic irrigation quota management, crucial for sustainable agricultural water use and food security in arid oasis regions.

Funding

• Corps Science and Technology Plan Project (Grant numbers: 2025DB013, 2023ZD064)
• National Natural Science Foundation of China (Grant numbers: 41661040, 52569004)
• Special project for innovation and development of Shihezi University (Grant numbers: CXFZ202217)

Citation

@article{SHEN2026Estimation,
  author = {SHEN, Liqiang and Hao, Jiaxin and Yao, Chenglong and Du, Xinyu and Cheng, Zengyi and Wang, Yuxuan and Chen, Fulong},
  title = {Estimation of water savings from farmland fallowing in the tarim river basin under food security and ecological security constraints and threshold effects of driving factors},
  journal = {Irrigation Science},
  year = {2026},
  doi = {10.1007/s00271-026-01108-2},
  url = {https://doi.org/10.1007/s00271-026-01108-2}
}