A remotely-sensed/modeling approach to monitor the the hydro-climatology of the Ogooué River Basin

Sakaros Bogning (LEGOS, France)

CoAuthors

Frédéric Frappart (LEGOS, France); Adrien Paris (CLS, France); Fabien Blarel (LEGOS, France); Fernando Niño (LEGOS, France); Stéphane Saux-Picard (CNRM, France); Pauline Lanet (CNRM, France); Frédérique Seyler (ESPACE-DEV, France); Gil Mahé (IRD, France); Raphaël Onguéné (Université de Douala, Cameroun); Jean-Pierre Bricquet (IRD, France); Jacques Etame (Université de Douala, Cameroun); Marie-Claire Paiz (TNC, Gabon); Jean-Jacques Braun (GET, France)

Event: 2019 Ocean Surface Topography Science Team Meeting

Session: Science IV: Altimetry for Cryosphere and Hydrology

Presentation type: Type Poster

Hydrological models are crucial tools for the simulation of
hydrological storage and fluxes in large basins and complex river systems
to compensate for reduction in watershed monitoring around the world in
recent decades. In this study, the hydrological model of large basins
(MGB) is used to evaluate the hydrological processes of the Ogooué River
Basin (ORB), which has been mostly unmonitored for about three decades.
Simulations were carried out over an 18-year period from 1998 to 2015
using TRMM 3B42 daily rainfall data from the Tropical Rainfall
Measurement Mission (TRMM) as forcing and in situ and altimetry-based
river discharges from ENVISAT, SARAL and Jason-2 for calibration and
validation. The results of the model were in good agreement with the
flows measured at stations upstream and downstream of the Ogooué basin
(Nash-Sutcliffe Efficiency (NSE)> 0.56 for all calibration gauges). The
MGB model efficiently describes the seasonal and interannual variations
of the flow in the Ogooué River and its major tributaries which were
found to be highly correlated to the rainfall (R ranging from 0.84 to
0.95 and 0.60 to 0.88 at seasonal and interannual time-scales
respectively). Interannual variations of precipitation and therefore of
river discharge of the ORB are linked to the El Niño Southern Oscillation
(ENSO) in the tropical eastern Pacific Ocean and southeastern tropical
Atlantic Niño. Also, the Ogooué river discharge was found to be strongly
correlated with Sea Surface Temperature (SST) at annual and semi-annual
time-scales.
 

Poster show times:

Room Start Date End Date
The Gallery Tue, Oct 22 2019,16:15 Tue, Oct 22 2019,18:00
The Gallery Thu, Oct 24 2019,14:00 Thu, Oct 24 2019,15:45
Sakaros Bogning
LEGOS
France
Sakaros.bogning@legos.osb-mip.fr