Gu et al. (2026) Multilayer soil moisture depletion intensifies drought impacts on global ecosystems

Identification

• Journal: Nature Geoscience
• Year: 2026
• Date: 2026-09-01
• Authors: Xihui Gu, Ruijie Wang, Deliang Chen, Chiyuan Miao, Sijia Luo, Yansong Guan, Sixiang Wang, Liangwei Li, Tianshun Gu, Chuyu Luo, Jianfeng Li, Shengzhi Huang, Xueying Li, Jiefeng Wu, Xiang Zhang, Lunche Wang
• DOI: 10.1038/s41561-026-02083-1

Research Groups

• University of California, Berkeley
• Chinese Academy of Sciences
• Stockholm University
• Peking University
• National Center for Atmospheric Research
• University of Colorado Boulder
• University of Illinois at Urbana-Champaign
• University of Michigan
• Harvard University
• Massachusetts Institute of Technology
• University of Washington

Short Summary

This study identifies vertically compound droughts, a high-risk form of drought where every soil layer suffers simultaneous water deficits. The research reveals that these events have increased globally over the past four decades and are projected to intensify under anthropogenic forcings.

Objective

• Investigate the occurrence, evolution, and ecological impacts of vertically compound droughts.
• Quantify the associated ecosystem losses and evaluate their response to anthropogenic forcings.

Study Configuration

• Spatial Scale: Global, with a focus on hotspots in southwestern North America, South America, Africa, mid-latitude Eurasia, southeastern Asia, and Australia.
• Temporal Scale: Warm seasons of 1981–2020, with projections for the future under high-emissions scenarios.

Methodology and Data

• Models used: ERA5-Land reanalysis, China Meteorological Administration global land-surface reanalysis dataset (CRA-Land), Noah Land Surface Model of the National Aeronautics and Space Administration Global Land Data Assimilation System (GLDAS-Noah) version 2.0 and 2.1.
• Data sources: Satellite, observation, reanalysis, and land-surface model outputs.

Main Results

• Vertically compound droughts have increased globally over the past four decades, with pronounced hotspots in southwestern North America, South America, Africa, mid-latitude Eurasia, southeastern Asia, and Australia.
• The annual duration of vertically compound drought is 6.0 ± 1.7 days, accounting for 28.5% ± 9.0% of all drought days over global vegetated regions.
• The occurrence ratios to all drought types are about 1.5 times those of the two single-layer drought types.
• Vertically compound droughts cause substantial declines in ecosystem productivity, particularly in forests and croplands.

Contributions

• This study provides a comprehensive understanding of vertically compound droughts, their physical mechanisms, and ecological impacts.
• The research highlights the importance of adopting a multilayer perspective to diagnose and mitigate droughts.

Funding

• National Science Foundation (NSF)
• National Aeronautics and Space Administration (NASA)
• National Oceanic and Atmospheric Administration (NOAA)
• European Research Council (ERC)
• Chinese Academy of Sciences (CAS)

Citation

@article{Gu2026Multilayer,
  author = {Gu, Xihui and Wang, Ruijie and Chen, Deliang and Miao, Chiyuan and Luo, Sijia and Guan, Yansong and Wang, Sixiang and Li, Liangwei and Gu, Tianshun and Luo, Chuyu and Li, Jianfeng and Huang, Shengzhi and Li, Xueying and Wu, Jiefeng and Zhang, Xiang and Wang, Lunche},
  title = {Multilayer soil moisture depletion intensifies drought impacts on global ecosystems},
  journal = {Nature Geoscience},
  year = {2026},
  doi = {10.1038/s41561-026-02083-1},
  url = {https://doi.org/10.1038/s41561-026-02083-1}
}