How a flood forecasting system saved lives and property in West Africa

Floods pose an increasing challenge for societies in West Africa; causing loss of lives, damaged infrastructure, and food insecurity. Improving flood management is hence paramount for the region, which several initiatives aim to contribute to. Hydrological forecasting systems can help, but only if they lead to appropriate action.

This presentation focusses on how a flood forecasting system has been used to save lives and property in West Africa within the FANFAR project (www.fanfar.eu). The system was co-designed and co-developed together with hydrological services, emergency management agencies, river basin organisations, and regional expert centres in 17 countries. The pilot system was launched early in the project, producing new forecasts every day. This enabled operational staff at national and regional agencies to utilize the system during the current rainy season, for every season since 2019.

During 2020, Nigeria experienced severe flooding. The Nigeria Hydrological Services Agency (NIHSA) hence decided to utilize FANFAR to warn the population of forthcoming flood risks, which resulted in 2 500 lives saved on one occasion, and minimisation of property damage on another. In the presentation we describe these events, and how NIHSA acted together with other institutions to entice action.

FANFAR was also used in Ivory Coast during the 2022 rainy season. Operational staff at SODEXAM – the meteorological services of Ivory Coast – utilized the system to inform two flood-prone communities of forthcoming flood risks. This resulted in on-the-fly construction of a drainage ditch, which reduced impacts on the nearby community. In the presentation we describe the event and also the approach SODEXAM took to build trust and communicate with the communities.

We also briefly describe the FANFAR system that employs a daily forecasting chain including meteorological reanalysis and forecasting based on HydroGFD, data assimilation of gauge observations, hydrological initialisation and forecasting with the HYPE model, flood severity assessment, and distribution through e.g. web visualisation.