Huang et al. (2026) Impacts of timescales on the relationship between compound drought-hot extremes based on precipitation and groundwater

Identification

• Journal: Journal of Environmental Management
• Year: 2026
• Date: 2026-03-20
• Authors: Runze Huang, Zengchao Hao, Alexander Sun, Xingyu Zhao, Yitong Zhang
• DOI: 10.1016/j.jenvman.2026.129372

Research Groups

• College of Water Sciences, Beijing Normal University, Beijing, China
• Bureau of Economic Geology, The University of Texas at Austin, Austin, TX, United States of America

Short Summary

This study investigates the spatial distribution and differences between compound groundwater droughts and hot extremes (CGDHEs) and compound meteorological droughts and hot extremes (CMDHEs), attributing these differences to hydrological lags. It identifies optimal precipitation timescales to reduce these discrepancies, thereby improving the potential for near-real-time monitoring of CGDHEs.

Objective

• To explore the spatial distribution of Compound Groundwater Droughts and Hot Extremes (CGDHEs).
• To investigate the differences between CGDHEs and Compound Meteorological Droughts and Hot Extremes (CMDHEs).
• To attribute these differences to the lags between meteorological droughts and groundwater droughts.
• To estimate the optimal timescale of accumulated precipitation corresponding to groundwater droughts to reduce differences in the distribution and changes in the two compound extremes.

Study Configuration

• Spatial Scale: Global (hotspots identified across multiple continents).
• Temporal Scale: Variable timescales for precipitation accumulation are analyzed; specific study period not detailed in provided text.

Methodology and Data

• Models used: Not explicitly specified (e.g., no named hydrological or climate models like ISBA, mHM). The study focuses on statistical analysis of relationships.
• Data sources: Precipitation and groundwater data; specific sources (e.g., satellite, observation, reanalysis) not detailed.

Main Results

• Hotspots of CGDHEs are predominantly found in northern South America, Europe, central and southern Africa, southeastern Asia, and eastern Australia.
• Significant differences exist between CMDHEs and CGDHEs, particularly pronounced in arid regions.
• Identifying the optimal timescale of accumulated precipitation corresponding to groundwater droughts substantially reduces the differences in the distribution and changes between the two compound extremes.
• This reduction is evidenced by higher correlation coefficients between the spatial extents of CMDHEs and CGDHEs when considering optimal timescales.
• The findings offer potential for improved near-real-time monitoring of CGDHEs.

Contributions

• Provides a comprehensive exploration of the global spatial distribution of Compound Groundwater Droughts and Hot Extremes (CGDHEs).
• Quantifies and attributes the observed differences between CGDHEs and Compound Meteorological Droughts and Hot Extremes (CMDHEs) to hydrological lag effects.
• Establishes a methodology to determine optimal precipitation accumulation timescales, which significantly improves the alignment between meteorological and groundwater drought indicators.
• Offers practical implications for enhancing near-real-time monitoring of groundwater droughts and informing water resources management strategies.

Funding

• Not specified in the provided text.

Citation

@article{Huang2026Impacts,
  author = {Huang, Runze and Hao, Zengchao and Sun, Alexander and Zhao, Xingyu and Zhang, Yitong},
  title = {Impacts of timescales on the relationship between compound drought-hot extremes based on precipitation and groundwater},
  journal = {Journal of Environmental Management},
  year = {2026},
  doi = {10.1016/j.jenvman.2026.129372},
  url = {https://doi.org/10.1016/j.jenvman.2026.129372}
}