Publications des scientifiques de l'IRD

Kitambo B., Papa Fabrice, Paris A., Tshimanga R. M., Calmant Stéphane, Fleischmann A. S., Frappart F., Becker M., Tourian M. J., Prigent C., Andriambeloson J. (2022). A combined use of in situ and satellite-derived observations to characterize surface hydrology and its variability in the Congo River basin. Hydrology and Earth System Sciences, 26 (7), p. 1857-1882. ISSN 1027-5606.

Titre du document
A combined use of in situ and satellite-derived observations to characterize surface hydrology and its variability in the Congo River basin
Année de publication
2022
Type de document
Article référencé dans le Web of Science WOS:000781088800001
Auteurs
Kitambo B., Papa Fabrice, Paris A., Tshimanga R. M., Calmant Stéphane, Fleischmann A. S., Frappart F., Becker M., Tourian M. J., Prigent C., Andriambeloson J.
Source
Hydrology and Earth System Sciences, 2022, 26 (7), p. 1857-1882 ISSN 1027-5606
The Congo River basin (CRB) is the second largest river system in the world, but its hydroclimatic characteristics remain relatively poorly known. Here, we jointly analyse a large record of in situ and satellite-derived observations, including a long-term time series of surface water height (SWH) from radar altimetry (a total of 2311 virtual stations) and surface water extent (SWE) from a multi-satellite technique, to characterize the CRB surface hydrology and its variability. First, we show that SWH from altimetry multi-missions agrees well with in situ water stage at various locations, with the root mean square deviation varying from 10 cm (with Sentinel-3A) to 75 cm (with European Remote Sensing satellite-2). SWE variability from multi-satellite observations also shows a plausible behaviour over a similar to 25-year period when evaluated against in situ observations from the subbasin to basin scale. Both datasets help to better characterize the large spatial and temporal variability in hydrological patterns across the basin, with SWH exhibiting an annual amplitude of more than 5 m in the northern subbasins, while the Congo River main stream and Cuvette Centrale tributaries vary in smaller proportions (1.5 to 4.5 m). Furthermore, SWH and SWE help illustrate the spatial distribution and different timings of the CRB annual flood dynamic and how each subbasin and tributary contribute to the hydrological regime at the outlet of the basin (the Brazzaville/Kinshasa station), including its peculiar bimodal pattern. Across the basin, we estimate the time lag and water travel time to reach the Brazzaville/Kinshasa station to range from 0-1 month in its vicinity in downstream parts of the basin and up to 3 months in remote areas and small tributaries. Northern subbasins and the central Congo region contribute highly to the large peak in December-January, while the southern part of the basin supplies water to both hydrological peaks, in particular to the moderate one in April-May. The results are supported using in situ observations at several locations in the basin. Our results contribute to a better characterization of the hydrological variability in the CRB and represent an unprecedented source of information for hydrological modelling and to study hydrological processes over the region.
Plan de classement
Hydrologie [062] ; Télédétection [126]
Description Géographique
CONGO ; CENTRAFRIQUE ; ZAMBIE ; TANZANIE ; RWANDA ; BURUNDI ; CAMEROUN ; ANGOLA
Localisation
Fonds IRD [F B010084638]
Identifiant IRD
fdi:010084638
Contact