by Benjamin Kitambo, University of Lubumbashi and Kinshasa, DRC / University of Toulouse III-Paul Sabatier, France
This Congo Science Focus post is from hydrologist Benjamin Kitambo (University of Lubumbashi and Kinshasa, DRC / University of Toulouse III-Paul Sabatier, France), lead author of a study giving new estimates of the surface water storage anomaly in the Congo Basin.
New estimates of the surface water storage anomaly in the Congo Basin were published in Earth System Science Data in July 2023. Combining observations from multiple satellites, the article is the first to present monthly variations in the surface water storage anomaly across the whole of this vast basin and at the sub-basin level over twenty-four years (1992-2015). Included in the estimates is inland freshwater stored in rivers, lakes, reservoirs, wetlands and floodplains. The findings enable exploration of the link between climate variability and water resources, especially during extreme events.
“The surface water storage dataset revealed the impact of local and regional variability, pointing out floods and droughts that recently affected the Congo Basin.”
Figure left: Time series of the Congo Basin’s surface water storage (a) and its deseasonalized anomaly (b).
Figure right: Anomaly of the Surface Water Storage maximum in %.
Two techniques based on the multi-sensor approach were employed that combined surface water extent from the Global Inundation Extent from Multi-Satellite dataset and surface water height from radar altimetry and topographic data. We found that surface water storage variations were characterized by a strong seasonal and interannual variability with an annual mean amplitude of ∼101 ± 23 km³. The Middle Congo sub-basin showed a higher mean annual amplitude of ∼71 ± 15 km³. The surface water storage dataset revealed the impact of local (rainfall distribution) and regional variability (climate mode) pointing out floods and droughts that recently affected the Congo Basin. The spatial distribution of the severe drought in late 2005 and early 2006 showed large negative anomalies of surface water storage (∼40 % deficit as compared to their long-term average).
Satellite-based observations are shown to be an effective source of information for improving understanding of hydrology in the Congo Basin where gauge stations are sparse.
The full study: A long-term monthly surface water storage dataset for the Congo basin from 1992 to 2015 is published in Earth System Science Data.
Related post: “Monitoring hydrological changes from space in a sparse gauged basin” by Benjamin Kitambo.
Header image shows Salonga National Park, DRC. Photo credit: Molly Bergen/WCS, WWF, WRI
Read more Congo Science Focus posts, highlighting publications led by scientists from the Congo Basin region.
