The Lake Chad hydrology under current climate change.

Area of Science:

• Hydrology
• Climate Change Science
• Ecology

Background:

• Lake Chad, vital for millions in the Sahel, has faced dramatic shrinkage, symbolizing climate change impacts.
• Past recovery was noted, but contemporary variability and future threats under climate change remain uncertain.

Purpose of the Study:

• To assess the recent hydrological changes and stability of Lake Chad's extent and volume.
• To provide a robust understanding of Lake Chad's current hydrology for climate adaptation strategies.

Main Methods:

• Utilized a novel multi-satellite approach to analyze Lake Chad's extent over the past two decades.
• Investigated the contribution of groundwater and tributary water supply to the lake's water storage.

Main Results:

• Lake Chad's overall extent has remained stable over the last 20 years, with a slight decrease in the northern pool.
• Groundwater levels have increased since the 2000s, driven by water supply from major tributaries.
• The lake seasonally recovers its surface water extent and volume, influenced by groundwater and tropical water sources.

Conclusions:

• Contrary to perceptions, Lake Chad is not shrinking and shows seasonal recovery.
• Findings offer a basis for developing effective climate adaptation strategies for the Lake Chad region.