Lian et al. (2026) Climate and land use change driving divergent surface water dynamics in the Northern China agro-pastoral ecotone

Identification

• Journal: Journal of Hydrology Regional Studies
• Year: 2026
• Date: 2026-01-06
• Authors: Jie Lian, Yulin Li, Xuyang Wang, yanqing Li, Yang Zhang, Jing FENG, Na SU, Y. F. Li
• DOI: 10.1016/j.ejrh.2025.103098

Research Groups

• Inner Mongolia Naiman Agroecosystem National Field Observation and Research Station/State Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
• College of Environment and Resources, Guangxi Normal University, Guilin, China
• School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou, China

Short Summary

This study quantifies surface water dynamics in Northern China's agro-pastoral ecotone (APE) from 1986-2020, revealing a net surface water loss and divergent watershed trends where anthropogenic interventions, especially irrigation and revegetation, have become more influential than climatic drivers in reconfiguring water distribution.

Objective

• Quantify the spatiotemporal dynamics of surface water bodies and net water yield (NWY) across the Northern China agro-pastoral ecotone (APE) watersheds.
• Investigate the effects of climate patterns and land use changes on these hydrological dynamics.

Study Configuration

• Spatial Scale: Northern China's agro-pastoral ecotone (APE), encompassing five major watersheds: Songhua River Basin (SHB), Liaohe River Basin (LB), Haihe River Basin (HB), Yellow River Basin (YB), and Inner Mongolia Endorheic Basin (EB).
• Temporal Scale: 1986–2020

Methodology and Data

• Models used:
  • Theil-Sen slope estimation
  • Sequential Mann-Kendall test
  • Piecewise Structural Equation Modeling (SEM)
  • GLEAM v4 (Global Land Evaporation Amsterdam Model version 4)
  • MODIS MOD16A2GF v061 (Terra Moderate Resolution Imaging Spectroradiometer)
• Data sources:
  • "Monthly Water History" global surface water product (European Commission Joint Research Centre, based on Landsat 5, 7, and 8 imagery via Google Earth Engine).
  • Historical land use/cover vector data (1:100000 scale) from Data Center for Resources and Environmental Sciences, Chinese Academy of Sciences (Landsat imagery).
  • China’s irrigation map (CIrrMap250, 250 m resolution, 2000–2020).
  • GlobPOP global gridded demographic dataset for population dynamics.
  • Gridded precipitation (PP) dataset (1 km resolution) from Science Data Bank (integrates records from >2400 meteorological stations).
  • Observed latent heat flux data from five eddy covariance flux tower sites (Inner Mongolia Station, Xilinhot Station, Duolun Station, Naiman Station) for evapotranspiration (ET) validation.
  • Observed annual discharge from representative hydrological stations (Tongliao, Taihekou, Daxingye in LB; Bayangol, Toudaoguai in YB) for Net Water Yield (NWY) validation.

Main Results

• The APE experienced marginally significant hydrological aridification during 1986–2020, characterized by a net surface water loss of -4140 hectares per year (p = 0.052) and a decline in water body numbers of -158.7 per year (p = 0.092).
• Watershed trends exhibited pronounced divergence:
  • Most severe depletion occurred in the Liaohe River Basin (LB) with -1523 hectares per year and -55.7 water bodies per year.
  • Moderate declines were observed in the Inner Mongolia Endorheic Basin (EB) with -716 hectares per year and -7.2 per year.
  • Significant expansion was found in the Yellow River Basin (YB) with 1169 hectares per year and 46.2 per year (p < 0.001).
• Major lakes and reservoirs across the APE underwent significant shrinkage, with Relative Water Area (RWA) declining at -1.22 % per year (p < 0.05), and the maximum shrinkage rate in the LB (-3.29 % per year, p < 0.001).
• A declining aridity index and intensified land use, particularly irrigation expansion and revegetation, amplified evapotranspiration (ET). Cropland areas since 2000 showed average ET increases of 1.9 ± 2.6 millimeters per year (GLEAM) and 6.5 ± 2.5 millimeters per year (MODIS), thereby diminishing Net Water Yield (NWY) across the APE.
• Structural Equation Modeling (SEM) revealed that anthropogenic interventions have outweighed climatic drivers in reconfiguring surface water distribution. Net Water Yield (NWY), despite being a climatic water surplus, showed a direct negative relationship with surface water area (-0.1292*), indicating human interception of water resources.

Contributions

• Quantified the complex interactions between climate forcing, land use intensification, and surface water dynamics across the Northern China agro-pastoral ecotone, providing a detailed spatiotemporal assessment.
• Demonstrated that anthropogenic interventions, such as irrigation expansion and revegetation, have become the dominant force in reconfiguring surface water distribution, often outweighing climatic wetting signals.
• Highlighted the "irrigation efficiency paradox" in the APE, where water-saving technologies can inadvertently lead to increased net regional water consumption due to agricultural expansion.
• Emphasized the critical need for watershed-specific water allocation frameworks and governance strategies to align human water use with bioclimatic thresholds for long-term regional water sustainability.

Funding

• “Open Bidding for Selecting the Best Candidates” Program of Inner Mongolia Autonomous Region (grant 2024JBGS0020)
• National Natural Science Foundation of China (41807525 and 42577550)
• Youth Innovation Promotion Association of Chinese Academy of Sciences (grant 2023449)
• Open Fund of Guangxi Key Laboratory of Environmental Processes and Remediation in Ecologically Fragile Regions, Guangxi Normal University (Grant EPRZR2025–03)

Citation

@article{Lian2026Climate,
  author = {Lian, Jie and Li, Yulin and Li, Yulin and Wang, Xuyang and Li, yanqing and Li, yanqing and Zhang, Yang and FENG, Jing and SU, Na and Li, Y. F. and Li, Y. F.},
  title = {Climate and land use change driving divergent surface water dynamics in the Northern China agro-pastoral ecotone},
  journal = {Journal of Hydrology Regional Studies},
  year = {2026},
  doi = {10.1016/j.ejrh.2025.103098},
  url = {https://doi.org/10.1016/j.ejrh.2025.103098}
}