Zeng et al. (2026) Spatiotemporal variations of precipitation-driven dry–wet boundaries and associated impacts from 1975 to 2025 in Mainland China

Identification

• Journal: npj Climate and Atmospheric Science
• Year: 2026
• Date: 2026-08-25
• Authors: Sihai Zeng, Xiaobo Yun, Hongjun Bao, Jianwen Wang
• DOI: 10.1038/s41612-026-01520-7

Research Groups

• College of Hydrology and Water Resources, Hohai University, Nanjing, China.
• China Meteorological Administration Hydro-Meteorology Key Laboratory, Beijing, China.
• National Meteorological Center, China Meteorological Administration, Beijing, China.
• School of Hydrology and Water Resources, Nanjing University of Information Science & Technology, Nanjing, China.

Short Summary

This study analyzes the spatiotemporal migration of China's core precipitation isohyets (200-, 400-, and 800-mm) and their associated impacts during 1975-2025. The results show significant wetting across northern basins but relative stability in southern humid basins.

Objective

• Investigate the spatial trajectories and abrupt decadal shifts of China's core precipitation isohyets (200-, 400-, and 800-mm) over the past 50 years.
• Quantify the areal reconfiguration of key climatic zones within each basin.

Study Configuration

• Spatial Scale: Mainland China, with a focus on nine major river basins.
• Temporal Scale: 1975-2025.

Methodology and Data

• Models used: Standardized Precipitation Index (SPI-3) and the Center of Gravity Migration Model.
• Data sources: High-density meteorological observations from 2474 national surface meteorological stations across Mainland China's nine major river basins.

Main Results

• The 200- and 400-mm isohyets exhibited distinct decadal-scale reorganizations, with changepoints in 1996 and 2011, respectively.
• The 800-mm humid boundary remained comparatively stable across Mainland China, despite a local adjustment in the HHRB.
• Rainstorm precipitation formed a distinct component of the post-2011 400-mm isohyet displacement.

Contributions

• This study provides direct quantitative displacement evidence for the recent reorganization of northern dry–wet boundaries.
• The results suggest that rainstorm precipitation played a significant role in the post-2011 westward adjustment of the 400-mm isohyet across the HRB and YRB.

Funding

• Not specified.

Citation

@article{Zeng2026Spatiotemporal,
  author = {Zeng, Sihai and Yun, Xiaobo and Bao, Hongjun and Wang, Jianwen},
  title = {Spatiotemporal variations of precipitation-driven dry–wet boundaries and associated impacts from 1975 to 2025 in Mainland China},
  journal = {npj Climate and Atmospheric Science},
  year = {2026},
  doi = {10.1038/s41612-026-01520-7},
  url = {https://doi.org/10.1038/s41612-026-01520-7}
}