Sources and Sinks of Water of the Cuvette Centrale Wetlands Using Multiple Remote Sensing Measurements and a Hydrologic Model

The wetlands in the Congo Basin play a significant role in dampening the flood waves in the fluvial system by storing water at flooding peaks and later releasing it. Quantifying the sources and sinks of the wetland waters is essential to understanding the routing of carbon, sedimentation, and other nutrients that are transported with the hydrological fluxes. In this study, we quantify the hydrological fluxes, including precipitation, upland runoff, evapotranspiration, and river-wetland exchanges supplying and draining the wetlands by integrating remote sensing measurements and modeling. Annually, river-wetland exchanges contribute less than 20% of the total inflows into the wetlands, whereas precipitation and runoff contribute to more than 80% of total inflows. However, river-wetland exchanges could contribute more than 20% and up to 90% of water storages in some wetlands at peak storage season. The river-wetland exchanges contribute 40% to 60% of the total outputs, while evaporation is responsible for the rest of the total outputs. Overall, our analysis results suggest that the Congo wetlands receive water from the river at peak storage season and supply water to the river most times of the year.