Wetlands of North Africa During the Mid‐Holocene were At Least Five Times the Area Today

Weizhe Chen (1, 2) , Philippe Ciais (1, 2) , Chunjing Qiu (1, 2) , Agnès Ducharne (3) , Dan Zhu , Shushi Peng , Pascale Braconnot (1, 2) , Chunju Huang

1 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
2 IPSL (FR_636) - Institut Pierre-Simon-Laplace
3 METIS - Milieux Environnementaux, Transferts et Interactions dans les hydrosystèmes et les Sols

The Sahara was significantly wetter and greener than today during the mid-Holocene (∼6,000 years before present), and those conditions were likely maintained by feedbacks from evaporating wetlands and riparian zones. A lack of spatially continuous wetland reconstruction is the major obstacle to investigating their impacts on climate and vegetation during that epoch. Here, we estimate high-resolution gridded wetland distribution up to 15″ in the mid-Holocene North Africa obtained with three statistical and hydrological modeling approaches forced by enhanced and calibrated precipitation from climate models. These wetland models have good performance for present-day conditions and reproduce mid-Holocene hydrological elements evaluated by 297 paleo-records. Simulation results show that 18.9 ± 4.0% of land surface in North Africa was covered by wetlands during the mid-Holocene. Our results highlight the impact of natural climate change on wetland areas and provide a data set for modeling studies to include wetland feedbacks.

Domaines: Océan, Atmosphère; Interfaces continentales, environnement

Weizhe Chen, Philippe Ciais, Chunjing Qiu, Agnès Ducharne, Dan Zhu, et al.. Wetlands of North Africa During the Mid‐Holocene were At Least Five Times the Area Today. Geophysical Research Letters, 2021, ⟨10.1029/2021GL094194⟩. ⟨hal-03373303⟩