Geng et al. (2026) Daily-scale propagation dynamics between meteorological and soil drought events in the Wei River Basin, China: a three-dimensional perspective

Identification

• Journal: Stochastic Environmental Research and Risk Assessment
• Year: 2026
• Date: 2026-04-01
• Authors: Guangpo Geng, Lijun Shan, Wenwen Zhang, Ping Wang, Mengxia Chen, Yulu Liu
• DOI: 10.1007/s00477-026-03210-5

Research Groups

• College of Geomatics, Xi’an University of Science and Technology, Xi’an, China

Short Summary

This study investigated the daily-scale spatiotemporal propagation dynamics between meteorological and soil droughts in the Wei River Basin using high-resolution data and a three-dimensional clustering and matching approach, revealing distinct characteristics and migration patterns for different drought types and propagation categories.

Objective

• To identify meteorological and soil drought events and extract their salient characteristics within a three-dimensional framework to analyze their dynamic evolution.
• To perform spatiotemporal matching of meteorological and soil drought events to construct corresponding event pairs.
• To explore the dynamics and spatiotemporal evolution of linkages between meteorological and soil droughts across multiple propagation categories.

Study Configuration

• Spatial Scale: Wei River Basin, China (approximately 134,800 km²), with data at 1 km spatial resolution.
• Temporal Scale: 2000–2022 (23 years), with daily temporal resolution.

Methodology and Data

• Models used:
  • Standardized Precipitation Evapotranspiration Index (SPEI-90d) for meteorological drought.
  • Standardized Soil Moisture Index (SSI-30d) for soil drought.
  • Three-dimensional (longitude-latitude-time) spatiotemporal clustering algorithm for event identification.
  • Spatiotemporal matching methods to form meteorological-soil drought event pairs.
• Data sources:
  • Daily meteorological data (precipitation, potential evapotranspiration) from the Multi-source Integrated China Meteorological Elements Dataset (ChinaMet).
  • Daily soil moisture data (0–40 cm depth) from the Soil Moisture of China based on In-situ measurements version 1.0 (SMCI1.0) dataset.

Main Results

• Meteorological drought (MD) events exhibited lower frequency (40 events) but greater severity and spatial extent compared to soil drought (SD) events, showing a weakening trend. In contrast, SD events had longer average duration (97.55 days), higher frequency (71 events), and an intensifying trend.
• MD centroids predominantly migrated East-Northeast (ENE), while SD centroids favored West-Northwest (WNW) and ENE directions, collectively indicating a predominant migration pattern along the northeast-southwest axis.
• The C2 category (single MD triggering multiple SDs) constituted the highest proportion of propagation events (72.9%).
• Matched drought event pairs demonstrated increased average duration (86.3 days for MD, 113.25 days for SD), affected area (85.96 × 10³ km² for MD, 68.63 × 10³ km² for SD), and migration distance (1.52 × 10³ km for MD, 0.797 × 10³ km for SD) compared to pre-matched events, suggesting MDs tend to induce more extensive and prolonged SDs. Small-scale events rarely propagated effectively.
• C1 category events propagated primarily along the northeast-southwest axis. C2 category events clustered in the northern study area (e.g., Yan’an) with transverse (east-west) propagation. C3 category events exhibited the longest propagation distance (245 km).

Contributions

• This study quantifies spatial propagation features (direction and distance) between meteorological and soil droughts using high spatiotemporal resolution data and a novel three-dimensional clustering and matching approach.
• It addresses limitations of previous grid-based statistical analyses that struggled to capture the nonlinear characteristics of drought evolution and lacked quantification of spatial propagation parameters.
• The research provides an intuitive and stereoscopic representation of drought propagation mechanisms, offering a comprehensive understanding of drought evolution pathways and dynamics.

Funding

• National Natural Science Foundation of China (Grant number: 41807503).

Citation

@article{Geng2026Dailyscale,
  author = {Geng, Guangpo and Shan, Lijun and Zhang, Wenwen and Wang, Ping and Chen, Mengxia and Liu, Yulu},
  title = {Daily-scale propagation dynamics between meteorological and soil drought events in the Wei River Basin, China: a three-dimensional perspective},
  journal = {Stochastic Environmental Research and Risk Assessment},
  year = {2026},
  doi = {10.1007/s00477-026-03210-5},
  url = {https://doi.org/10.1007/s00477-026-03210-5}
}