Bridging the gap between scientific knowledge and action in flood risk management: two attempts of co-construction project between scientists and stakeholders in Senegal and Burkina Faso in the AMMA2050 program.

In West Africa, the increase in the frequency of extreme rainfall in the context of global warming accentuates the risk of damaging floods, particularly in cities that concentrate a rapidly a rapidly growing population. Decision-makers and managers in charge of hydrological risks are increasingly aware of the challenges raised climate change, but their ability to define suitable adaptation strategies remains limited by the lack of tangible and usable scientific information. On the other hand, scientists are developing increasingly sophisticated knowledge on climate change and hydrological impacts in West Africa but are often struggling to translate research results into operational and usable decision support tools.

What is now commonly referred to as the "knowledge-action gap" calls for strengthening the link between scientists and decision-makers and requires the implementation of co-construction strategies that sometimes push actors and scientists to move out of their comfort zone.

Here we will present two attempts of co-construction experiments conducted between 2016 and 2021 within the AMMA2050 program. The first experiment concerns the development of intensity-duration-frequency curves in collaboration with the national meteorological service of Senegal (ANACIM) in order to integrate these curves into the agency's operational climate services. The second experiment  is an attempt to co-construct a climate-hydrology-flood modeling chain between scientists and decision-makers involved in urban planning for the future management of urban floods in the city of Ouagadougou, Burkina Faso.

The objective here is to highlight (i) the technical scientific advances that make it possible to propose useful, usable and, as far as possible, used scientific information; (ii) the functional modes of interaction with decision-makers and (iii) the successes and failures in the approaches taken, (iv) the lessons learned from these two experiences that could help facilitate future co-construction approaches.