Zheng et al. (2026) An improved SCF‑SWE relationship function with topographic controls for enhanced snowmelt runoff simulation

Identification

• Journal: Journal of Hydrology Regional Studies
• Year: 2026
• Date: 2026-09-12
• Authors: Liyuan Zheng, Yanhong Dou, Weihong Liao, Shuqiang Nian, Yunzhong Jiang, Hao Wang
• DOI: 10.1016/j.ejrh.2026.103969

Research Groups

• College of Environment and Ecology, Xiamen University
• Research Center on Flood and Drought Disaster Prevention and Reduction of the Ministry of Water Resources
• State Key Laboratory of Water Cycle and Water Security, China Institute of Water Resource and Hydropower Research
• School of Civil Engineering, Tianjin University

Short Summary

This study proposes an improved snow cover fraction (SCF)-snow water equivalent (SWE) relationship function that incorporates topographic controls for enhanced snowmelt runoff simulation in the Yarlung Zangbo River Basin. The new function significantly boosts runoff prediction accuracy, with average Nash-Sutcliffe efficiency increasing from 0.763 to 0.899 and percent bias dropping from 11.29% to 6.25%.

Objective

• To improve the snowmelt runoff simulation accuracy of the EasyDHM model in the Yarlung Zangbo River Basin by developing an improved SCF-SWE relationship function that incorporates topographic controls.

Study Configuration

• Spatial Scale: The study area is the Yarlung Zangbo River Basin, a high-altitude alpine-glacial basin in Xizang, southwestern China.
• Temporal Scale: The study period covers 2002-2018, with a daily time step for simulation.

Methodology and Data

• Models used: EasyDHM (Easy Distributed Hydrological Model)
• Data sources: Meteorological element data from national meteorological stations, streamflow data from hydrological sections, snow data from MODIS Normalized Difference Snow Index (NDSI) data, and topographic data from Digital Elevation Model (DEM).

Main Results

• The improved SCF-SWE relationship function significantly improves runoff prediction accuracy, with average Nash-Sutcliffe efficiency increasing from 0.763 to 0.899 and percent bias dropping from 11.29% to 6.25%.
• The model eliminates the premature snowmelt runoff typically generated by the baseline model, aligning the simulated hydrograph phase with observations.

Contributions

• This study provides a physically consistent framework for high-fidelity snowmelt-runoff modeling in high-altitude cold regions.
• The improved SCF-SWE relationship function can be applied to other similar basins with complex topography and climate conditions.

Funding

• National Natural Science Foundation of China (Grant No. 51979223)
• National Key Research and Development Program of China (Grant No. 2017YFC0406301)

Citation

@article{Zheng2026improved,
  author = {Zheng, Liyuan and Dou, Yanhong and Liao, Weihong and Nian, Shuqiang and Jiang, Yunzhong and Wang, Hao},
  title = {An improved SCF‑SWE relationship function with topographic controls for enhanced snowmelt runoff simulation},
  journal = {Journal of Hydrology Regional Studies},
  year = {2026},
  doi = {10.1016/j.ejrh.2026.103969},
  url = {https://doi.org/10.1016/j.ejrh.2026.103969}
}