Li et al. (2026) How emergent-constrained precipitation projections reshape watershed hydrology?

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-07-30
• Authors: Yilan Li, Tongbi Tu, Xiaohong Chen
• DOI: 10.1016/j.jhydrol.2026.136145

Research Groups

Center of Water Resources and Environment, School of Civil Engineering, Sun Yat-Sen University, Guangzhou 510275, China

Short Summary

This study develops a novel model-selection-based emergent constraint framework to constrain CMIP6 precipitation projections and reduce inter-model spread in watershed hydrology. The constrained projections improve projected precipitation growth rates by 7–84% relative to the raw CMIP6 ensemble.

Objective

• Investigate how emergent-constrained precipitation projections reshape watershed hydrology

Study Configuration

• Spatial Scale: Watershed scale, focusing on the Xijiang River Basin as a testbed
• Temporal Scale: Multiple temporal scales, including annual and monthly runoff uncertainties

Methodology and Data

• Models used: CMIP6 global climate models (GCMs)
• Data sources: Historical and future precipitation projections from CMIP6, combined with hydrological modeling framework

Main Results

• The emergent constraint increases projected precipitation growth rates by 7–84% relative to the raw CMIP6 ensemble.
• Reduced precipitation uncertainty propagates through watershed processes across multiple temporal scales, but corresponding reductions in hydrological uncertainty are relatively modest.

Contributions

• This study demonstrates the effectiveness of a model-selection-based emergent constraint framework for identifying GCMs suitable for regional projections and reducing precipitation uncertainty.
• The results highlight the nonlinear and scale-dependent propagation of climate signals through watershed processes, underscoring the need for more accurate and reliable climate predictions.

Funding

• This research was supported by the National Natural Science Foundation of China (Grant No. 51979215) and the Guangdong Provincial Key Laboratory of Water Resources and Environment (Grant No. 2020B1212010001).

Citation

@article{Li2026How,
  author = {Li, Yilan and Tu, Tongbi and Chen, Xiaohong},
  title = {How emergent-constrained precipitation projections reshape watershed hydrology?},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.136145},
  url = {https://doi.org/10.1016/j.jhydrol.2026.136145}
}