High-resolution spatiotemporal analysis of drought dynamics in Iran

Area of Science:

• Climatology
• Environmental Science
• Hydrology

Background:

• Understanding drought patterns is crucial for water resource management and climate change adaptation.
• High-resolution climate data enables detailed analysis of drought dynamics and temporal variations.

Purpose of the Study:

• To investigate drought trends and characteristics in Iran from 1958 to 2022.
• To analyze drought severity, duration, affected area, and migration patterns using high-resolution data.

Main Methods:

• Utilized the self-calibrated Palmer Drought Severity Index (scPDSI).
• Employed high-resolution TerraClimate data (4 km resolution) for the period 1958–2022.
• Identified 558 drought occurrences and analyzed trends in migration distance, duration, and affected area.

Main Results:

• Drought migration distance decreased significantly (-42.135 km/year), indicating increased stationarity.
• Drought duration and affected area showed increasing trends (0.0767 month/year and 41,055 km²/year, respectively).
• Drought magnitude exhibited a cyclical pattern; severe droughts concentrated in western/northwestern Iran, with increased frequency since 1999.

Conclusions:

• Droughts in Iran are becoming more persistent, widespread, and locally intense.
• Seasonal analysis indicates higher severity during spring and winter.
• Findings highlight the need for adaptive strategies to mitigate the impacts of intensifying drought conditions.