COP22 19/02/2016

Hydrology : monitoring floodwaters

The two major challenges covering all of these themes are the preservation of environmental resources and ecosystems, and universal access to water (mainly for drinking) and sanitation. In this context, CNES has been commissioned to support the development of satellite applications and services in the field of water, in particular. 

These products and services will rely on all satellite missions that generate relevant data on water. This currently includes Sentinel-1,2,3 Pleiades and Meghtropiques. For the future, the SWOT (Surface Water and Ocean Topography) mission is awaited with great interest. SWOT will enable global coverage of inland waters and provide spatio-temporal variations in the water height of rivers and lakes. In the meantime, the Sentinel-3 altimeter will provide measurements on inland waters that are more accurate than those of most previous altimetry missions.Sentinel-3, with its SRAL instrument, will enable more precise characterization, and will complement the JASON missions while awaiting the global coverage to be provided by the forthcoming SWOT mission. The Sentinel-3 altimeter is now highly anticipated for the study and management of inland waters. Its data will be integrated in the Copernicus Global Land Services platform, which will offer free, open, online access to hydrological data acquired from space. CLS, alongside CNES, LEGOS, CESBIO and many other partners, is working to optimize the acquisition, processing, distribution and exploitation of these hydrological data.

Thanks to Sentinel-3, the other satellite missions we use and our expertise in altimetry (measuring the height of water), when flooding occurs, we are able, for instance, to monitor the water level in order to anticipate flooding of infrastructure located further downstream. This is what we did for one of our customers. A major flood of the Benoué River had serious consequences for local populations and infrastructure. Our customer, who had infrastructures in the Niger Delta, wanted to know whether the flood was over and whether it could return to its plants without putting its employees in danger. The satellite altimetry data we analyzed showed that most of the water located upstream had already flowed downstream, and that the floodwaters were in the process of receding. This information was vital to our customer for managing the site. With Sentinel-3, we will be able to perform this kind of monitoring on smaller tributaries and area not yet covered