Afzal et al. (2026) Contrasting roles of climate change and land-use change on runoff dynamics in a semi-humid monsoon watershed of China

Identification

• Journal: Scientific Reports
• Year: 2026
• Date: 2026-09-06
• Authors: Muhammad Mannan Afzal, Adeel Ahmad Nadeem, Qiaoling Li, Fazli Hameed, Anis ur Rehman Khalil, Xin Yang, Li Zhijia, Shiyin Liu
• DOI: 10.1038/s41598-026-67812-3

Research Groups

• Institute of International Rivers and Eco-Security, Yunnan University, China
• Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Yunnan University, China
• Key Laboratory of Agricultural Water Resources, Institute of Genetics and Developmental Biology, Centre for Agricultural Resources Research, Chinese Academy of Sciences, China
• College of Hydrology and Water Resources, Hohai University, China
• Directorate of Onfarm Water Management, KPK Government, Pakistan

Short Summary

This study quantifies the individual and combined impacts of climate variability and land-use change on runoff in the Dongwan Watershed, China. It finds that climate change is the primary driver of runoff dynamics, while land-use change acts as a secondary, moderating factor.

Objective

• To examine the separate and combined effects of climate variability and land-use change on historical and future runoff dynamics in the Dongwan Watershed (the largest sub-basin of the Yihe River).

Study Configuration

• Spatial Scale: Dongwan Watershed, Yihe River, China (semi-humid monsoon region).
• Temporal Scale: Historical analysis (comparing 1971–1990 and 1991–2010) and future projections based on CMIP6 scenarios.

Methodology and Data

• Models used: Soil and Water Assessment Tool (SWAT) for runoff simulation; Cellular Automata-Markov (CA-Markov) for land-use projections.
• Data sources: Five CMIP6 General Circulation Models (GCMs) under three Shared Socioeconomic Pathways (SSP126, SSP370, and SSP585).

Main Results

• Model Performance: The SWAT model demonstrated high reliability with Nash–Sutcliffe Efficiency (NSE) values of 0.87 for calibration and 0.85 for validation.
• Historical Attribution (1971–1990 vs 1991–2010):
  • Climate variability contributed to a 121.1% increase in annual runoff.
  • Land-use change exerted a compensating (reducing) effect of -25.4%.
  • The net result was a modest 3.0% increase in total annual runoff.
• Seasonal Dynamics: Significant shifts were observed, with summer runoff increasing by 21.7%, while winter (-32.2%), spring (-8.1%), and autumn (-8.9%) runoff declined.
• Future Projections: Climate change will continue to be the dominant driver, amplifying seasonal contrasts (higher summer flood risk and increased dry-season water scarcity). Forest expansion is projected to moderately dampen these increases but will not offset the intensified climatic forcing.

Contributions

• The study disentangles the contrasting roles of climate and land-use changes in a semi-humid monsoon watershed, highlighting that while land-use changes (such as forest expansion) can moderate runoff, they are insufficient to counteract the primary influence of climate change.

Funding

• This research received no external funding.

Citation

@article{Afzal2026Contrasting,
  author = {Afzal, Muhammad Mannan and Nadeem, Adeel Ahmad and Li, Qiaoling and Hameed, Fazli and Khalil, Anis ur Rehman and Yang, Xin and Zhijia, Li and Liu, Shiyin},
  title = {Contrasting roles of climate change and land-use change on runoff dynamics in a semi-humid monsoon watershed of China},
  journal = {Scientific Reports},
  year = {2026},
  doi = {10.1038/s41598-026-67812-3},
  url = {https://doi.org/10.1038/s41598-026-67812-3}
}