Observing, understanding and forecasting the dynamics of our planet

Radar altimetry, initially developed to observe the surface topography of the ocean, is now commonly used for the monitoring of inland water bodies. In this study, an altimetry-based gauging network was built in the Ogooué River Basin (ORB), in Gabon, Central Africa. It is composed of altimetry-based virtual stations (VS) under the altimetry tracks of ERS-2/ENVISAT/ SARAL, Cryosat-2, Sentinel-3A and Jason-2/Jason-3. River discharge was estimated from 1995 to 2017 combining water level records from several virtual stations close to Lambaréné gauge station and the rating curve from this station. Very good agreement was found in terms of R (>0.95), RMSE and annual discharge

African coastal camera network efforts at monitoring ocean, climate, and human impacts

(IF 4.99; Q1)International audienceRegular and long-term monitoring of coastal areas is a prerequisite to avoiding or mitigating the impacts of climate and human-driven hazards. In Africa, where populations and infrastructures are particularly exposed to risk, there is an urgent need to establish coastal monitoring, as observations are generally scarce. Measurement campaigns and very high-resolution satellite imagery are costly, while freely available satellite observations have temporal and spatial resolutions that are not suited to capture the event scale. To address the gap, a network of low-cost, multi-variable, shore-based video camera systems has been installed along the African coasts. Here, we present this network and its principle of sharing data, methods, and results obtained, building toward the implementation of a common integrated coastal management policy between countries. Further, we list new contributions to the understanding of still poorly documented African beaches' evolution, waves, and sea level impacts. This network is a solid platform for the development of inter-disciplinary observations for resources and ecology (such as fisheries, and sargassum landing), erosion and flooding, early warning systems during extreme events, and science-based coastal infrastructure management for sustainable future coasts