Yan et al. (2026) Attribution of runoff changes in the semi-arid Xiliao River Basin – A Budyko-elasticity approach to deconstructing compound climate and human impacts

Identification

• Journal: Agricultural Water Management
• Year: 2026
• Date: 2026-03-14
• Authors: Xiangzhao Yan, Yanwei Zhao, Xiong Zhou, Weiqi Xiang, Yongpeng Chen, Jiaqi Chen
• DOI: 10.1016/j.agwat.2026.110288

Research Groups

• State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
• Institute for Energy, Environment and Sustainable Communities, University of Regina, Regina, SK S4S 0A2, Canada

Short Summary

This study quantified the contributions of climate change and human activities to runoff reduction in the semi-arid Xiliao River Basin from 1980 to 2022 using a Budyko-elasticity framework, revealing an abrupt runoff decline in 2002 with significant spatial heterogeneity: upstream areas are climate-driven, while middle-downstream areas are human-driven, primarily due to agricultural irrigation.

Objective

• To quantify the contributions of climate change and human activities to runoff reduction in the Xiliao River Basin from 1980 to 2022.
• To analyze the spatiotemporal variation characteristics of land use and ecological conditions within the basin.
• To detect trends and change points in runoff time series and divide the study period into baseline and change periods.
• To evaluate the sensitivity and contribution rate of climate factors (precipitation, potential evapotranspiration) and underlying surface factors to runoff changes using the Budyko-elastic coefficient attribution framework, and reveal the intrinsic mechanism of spatial heterogeneity of runoff driving factors.

Study Configuration

• Spatial Scale: Xiliao River Basin (130,977 square kilometers), divided into sub-basins based on six hydrological stations (upper, middle, and lower reaches). Data resolutions: 90-meter Digital Elevation Model (DEM), 1-kilometer monthly climate data, 30-meter land use data, 0.1-degree monthly sectoral water use data.
• Temporal Scale: 1980–2022 (43 years), divided into a baseline period (1980–2001) and a change period (2002–2022) based on an abrupt change point in 2002.

Methodology and Data

• Models used: Budyko-elasticity framework, Mann-Kendall (M-K) trend test, Pettitt’s change-point test, Theil-Sen slope test.
• Data sources:
  • Runoff data (1980–2022) from six hydrological observation stations in the Xiliao River Basin.
  • 90-meter resolution Digital Elevation Model (DEM).
  • Annual precipitation and potential evapotranspiration datasets (1-kilometer monthly) from the China 1-km Monthly Dataset.
  • Multi-year land use data (30-meter).
  • NDVI data (1981–2023 daily).
  • Water use data for various sectors (0.1-degree monthly) from the High-resolution Sectoral Water use Dataset (HSWUD) for China.

Main Results

• The annual runoff in the Xiliao River Basin underwent an abrupt decline in 2002. After this change (2002–2022), runoff decreased significantly compared to the baseline period (1980–2001), with declines ranging from 51.59% to 98.08% across sub-basins. The average runoff during the change period was 0.63 mm, a decrease of 6.61 mm.
• Runoff changes exhibited significant spatial heterogeneity, characterized as "upstream climate-driven, middle-downstream human-driven."
• In the upstream sub-basins (e.g., BLQ, HRS), climate change was the dominant driver of runoff decline, with precipitation reduction contributing 52.6%–64.1%. The upstream region showed a significant upward trend in the drought index in nearly 45% of the area.
• In the middle and lower reaches (e.g., CF, MX, ZJT sub-basins), changes in underlying surface parameters were the primary factors, contributing 75.7%–78.9% to runoff reduction.
• Decomposition of underlying surface parameters confirmed that high-intensity direct water withdrawal for agricultural irrigation, rather than indirect ecological effects of vegetation restoration, was the fundamental cause of runoff depletion in the middle and lower reaches. Agricultural irrigation water use increased by over 40% annually in these areas.
• A superimposed effect was identified, where upstream climate-induced drought exacerbates downstream water shortages.

Contributions

• This study overcomes the limitation of treating large watersheds as homogeneous units, revealing significant spatial heterogeneity in runoff drivers (climate-driven upstream, human-driven middle-downstream) in a semi-arid agro-pastoral ecotone, thereby refining the theoretical framework for hydrological responses.
• It decomposes the comprehensive impact of underlying surface parameters in the Budyko framework into indirect (vegetation restoration) and direct (water withdrawal) pathways, clarifying that direct agricultural irrigation is the primary human activity driving runoff depletion in the middle and lower reaches.
• The study reveals interactive effects on watershed hydrological response, demonstrating that downstream runoff depletion is not only due to local water withdrawal but also exacerbated by reduced upstream inflows from climatic drought, addressing the limitation of focusing on isolated sub-basins.
• It provides critical reference for resolving regional water resource conflicts and promoting coordinated ecological and economic development in semi-arid basins, particularly by highlighting the need for zonal precision management and controlling agricultural irrigation quotas.

Funding

• Major Demonstration Project for Scientific and Technological Innovation in Inner Mongolia Autonomous Region (2025ZDSF001704).

Citation

@article{Yan2026Attribution,
  author = {Yan, Xiangzhao and Zhao, Yanwei and Zhou, Xiong and Xiang, Weiqi and Chen, Yongpeng and Chen, Jiaqi},
  title = {Attribution of runoff changes in the semi-arid Xiliao River Basin – A Budyko-elasticity approach to deconstructing compound climate and human impacts},
  journal = {Agricultural Water Management},
  year = {2026},
  doi = {10.1016/j.agwat.2026.110288},
  url = {https://doi.org/10.1016/j.agwat.2026.110288}
}