Data rescue and valorization of old climatological data - application to rainfall data in Burkina Faso and Ivory Coast using NUNIEAU software

In 2011, the XVI World Meteorological Congress Resolution 16 gives priority to the rescue and digitization of climate archives and to promote global and regional initiatives to collaborate on DARE (data rescue) and the exchange of scientific knowledge and related technological advances. The Congress urged Members to make every effort to prevent the deterioration of climate-relevant data and to make these data available to support climate change analyses and relevant climate services. In the framework of operational and scientific research actions around the updating of hydrological standards in West Africa (Actualisation des Normes hydrologiques en Afrique de l'Ouest - ActNAO Project) and in response to the WMO call, we used the NUNIEAU software (NUmerisation de NIveaux d'EAU en mer ou en rivieres - free software from CEREMA) which allows the digitization of different types of paper documents by automatic recognition. This software has been used on rainfall pluviograms in Burkina Faso and Cote d'Ivoire. The use of this tool allows rainfall analysis on intraday time steps, a time step that is very useful for the knowledge and management of flash-flood events in small basins, especially urban basins. Illustrated by a few scientific results, access to these data, which remains very limited in West Africa, opens up fields of analysis that are not only disciplinary but also, and above all, inter or transdisciplinary.