Ning et al. (2026) Spatiotemporal Variability of China's 800 mm Precipitation Isohyet (1961–2022): Multi-scale Analysis of its Migration and Impact on Hydroclimatic Extremes

Identification

• Journal: Atmospheric Research
• Year: 2026
• Date: 2026-01-12
• Authors: Shaowei Ning, Le Chen, Rujian Long, Zhou Yf, Yi Cui, M. M. Zhang, Licahng Xu, Juliang Jin, Thapa bthapa
• DOI: 10.1016/j.atmosres.2026.108770

Research Groups

• College of Civil Engineering, Hefei University of Technology, Hefei, China
• Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China
• School of Geography and Planning, Sun Yat-sen University, Guangzhou, China
• Nepal Academy of Science and Technology, Lalitpur, Nepal
• University of Chinese Academy of Sciences, Beijing, China

Short Summary

This study introduces the Dynamic Line Scanning Method (DLSM) to quantitatively analyze the migration of China's 800 mm precipitation isohyet from 1961–2022, revealing a two-phase shift (southward retreat followed by accelerated northward movement) that significantly impacts regional drought-flood patterns and extreme precipitation events, primarily driven by the East Asian Summer Monsoon.

Objective

• To quantitatively assess the spatiotemporal migration of China's 800 mm precipitation isohyet during 1961–2022 using a novel Dynamic Line Scanning Method (DLSM).
• To explore the links between the isohyet's shifts and regional drought–flood regimes, extreme precipitation events, and identify the main driving factors.

Study Configuration

• Spatial Scale: China
• Temporal Scale: 1961–2022 (62 years)

Methodology and Data

• Models used: Dynamic Line Scanning Method (DLSM)
• Data sources: Long-term precipitation data (e.g., China Gauge-based Daily Precipitation Analysis (CGDPA), China Hydro-Meteorology Precipitation Dataset (CHM_PRE), China Meteorological Administration Gridded Climate Dataset Version 05.1 (CN05.1))

Main Results

• The 800 mm precipitation isohyet in China exhibited a two-phase shift: an initial southward retreat followed by an accelerated northward movement after 2001, with the latter trend intensifying.
• These shifts directly influenced regional drought–flood patterns and altered the frequency and intensity of extreme precipitation events.
• The East Asian Summer Monsoon Index (EASMI) was identified as the dominant factor driving the movement of the 800 mm precipitation isohyet.

Contributions

• Proposes a novel methodological approach, the Dynamic Line Scanning Method (DLSM), for quantitatively assessing the migration of precipitation isohyets.
• Provides robust empirical evidence on the dynamics of China's 800 mm precipitation isohyet under climate change.
• Enhances understanding of hydroclimatic variability and offers a scientific foundation for region-specific adaptation and water management strategies.

Funding

• Not specified in the provided text.

Citation

@article{Ning2026Spatiotemporal,
  author = {Ning, Shaowei and Chen, Le and Long, Rujian and Yf, Zhou and Cui, Yi and Zhang, M. M. and Xu, Licahng and Jin, Juliang and bthapa, Thapa},
  title = {Spatiotemporal Variability of China's 800 mm Precipitation Isohyet (1961–2022): Multi-scale Analysis of its Migration and Impact on Hydroclimatic Extremes},
  journal = {Atmospheric Research},
  year = {2026},
  doi = {10.1016/j.atmosres.2026.108770},
  url = {https://doi.org/10.1016/j.atmosres.2026.108770}
}