Global eight drought types: Spatio-temporal characteristics and vegetation response.

Area of Science:

• Environmental Science
• Climate Science
• Ecology

Background:

• Traditional drought classifications oversimplify global drought phenomena and their impacts.
• A deeper understanding of drought characteristics and vegetation responses is needed.

Purpose of the Study:

• To develop a novel categorization framework for global drought events.
• To analyze the spatiotemporal characteristics and trends of flash droughts (FD) and seasonal droughts (SD).
• To investigate vegetation responses to different drought types.

Main Methods:

• Utilized soil moisture percentile methods and the Soil Moisture Anomaly Percentage Index (SMAPI).
• Created global time series for FD and SD from 1981 to 2020.
• Employed a set relationship identification method to categorize eight distinct drought types.

Main Results:

• Independent FD and Inclusion FD frequencies declined post-2011, with FD most frequent in humid areas.
• Inclusion FD and SD were most frequent in arid areas, decreasing with humidity.
• Independent SD frequency increased post-2011, peaking in semi-arid regions.
• FD duration showed a U-shaped trend, while SD duration decreased with humidity.
• Vegetation response times to drought varied between arid and humid regions.

Conclusions:

• The novel drought categorization framework provides a more nuanced understanding of global drought dynamics.
• Drought characteristics and their impacts on vegetation exhibit significant spatial and temporal variability.
• Findings highlight the need for tailored drought management strategies based on drought type and regional aridity.