OiEAU ANNUAL REPORT - 2019

Spatial hydrology: an innovative data collection tool Since 2014, OiEau has been leading, with the French Development Agency, a working group on spatial hydrology for monitoring water resources by satellite, gathering the National Center for Space Studies and the Research Institute for Development. In this context, a first phase of cooperation was initiated in 2016 with the International Commission of the Congo-Ubangui-Sangha Basin (CICOS) and AFD support, for monitoring the Congo River. The work undertaken has allowed establishing, with the BRLi consulting firm, a Hydrological Information System as well as post-activity services with the “Compagnie Nationale du Rhône” (National Rhone Company). Hydrologicalmonitoringof rivers is fundamental for the sustainable management of water resources and associated ecosystems, especially in the context of climate change. However, in some regions of the world, the hydrometric stations are few and often tend to decline, especially due to their geographic isolation and maintenance cost. Measuring water depths by satellite (spatial altimetry), with increasingly fine resolutions, therefore appears to be a promising technology to supplement field data. « Being aware of the challenges linked to knowledge of the resource, the working group on spatial hydrology is responsible for reconciling scientific and technical visions with the users’ needs, especially in regions most vulnerable to climate change. Our group now extends its activities to other basins such as those of the Niger and Senegal rivers. The working group draws on French expertise and gathers the following institutions: AFD, CNES, IRD, INRAE, CLS, CNR, BRLi and OiEau. » Mr. Brachet, Executive assistant - OiEau Virtual stations showing water depths measured by satellite in the Congo Basin accessible from the CICOS HIS (May 2019). ©OiEau 15 th Meeting of the working group on spatial hydrology for future activities in the Niger and Senegal River Basins (Paris, 12/10/2019). ©OiEau Short-term prospects for spatial hydrology, seen by Mr. Maisongrande - Land & Hydrology Program Manager - CNES “The global monitoring of water resources is a major societal challenge for which space techniques have a determining role to play. The French- American Surface Water Ocean Topography mission planned for 2021 will aim to collect the needs of hydrologists in a single satellite and will provide a compendium of hydrographicdataunprecedented on a planetary scale”. 33