Exploring evapotranspiration dynamics over Sub-Sahara Africa (2000-2014)

Area of Science:

• Environmental Science
• Climate Science
• Hydrology

Background:

• Evapotranspiration (ET) monitoring is crucial for water resource management, crop stress assessment, and understanding drought vulnerability in agricultural regions.
• Climate variability impacts on ET dynamics are vital for adaptation strategies but are often unreported or undetermined in many regions.

Purpose of the Study:

• To explore changes in Moderate Resolution Imaging Spectroradiometer (MODIS)-derived ET from 2000-2014 across Sub-Sahara Africa (SSA).
• To identify dominant modes of ET variability and analyze trends in relation to climate and soil moisture.
• To investigate the drivers of ET dynamics in SSA's terrestrial ecosystems.

Main Methods:

• Multivariate analyses were employed to identify leading modes of ET variability.
• Man-Kendall's statistics were used to assess the significance of ET trends.
• Spatio-temporal drought analysis was conducted to understand ET losses.

Main Results:

• Four leading modes accounted for approximately 90% of ET variability, primarily in the Sudano-Sahel and Congo basin.
• Significant positive ET trends were observed in the Central African Republic and the Sahel.
• Widespread negative ET trends were found in the Congo basin, consistent with soil moisture deficits.

Conclusions:

• ET dynamics in SSA are complex, influenced by factors beyond natural climate variations.
• Soil moisture deficits were identified as a key driver of ET losses in the Congo basin.
• Understanding these ET trends is essential for developing effective water management adaptation strategies in drought-vulnerable regions.