Lessons learnt

A similar study previously conducted forcing the HYPE hydrological model with the ECMWF System 4 seasonal forecast indicates that the quality of seasonal hydrological forecasts may be improved. Accessibility to data and methodology was made possible thanks to the collaboration between the AGRHYMET Regional Center and its partner institutions including SMHI. Interactions between institutions producing climate data and large-scale tools and local institutions allow their practical use to solve recurring societal problems in our regions such as adaptation to extreme events (floods and droughts), improvement of agricultural production. It is also important to point out that some planned activities are not always carried out due to lack of technical resources. This is the case, for example, of the DBS bias correction method that was planned for this study.

Importance and relevance of adaptation

In West Africa, climate variability and change were assessed on the basis of indigenous knowledge. For example, the behavior of some birds is used to determine the start of the rainy season. The efforts made in recent years and the current outlook for seasonal forecasting are helping to better qualify and quantify the physical processes responsible for the different characteristics of the rainy season in West Africa. For instance, in agriculture, an evaluation showed that agrometeorological assistance through the provision of climate services contributed to an increase in agricultural production in Mali of about 30% (Gnoumou  Faustin  and al.,  2006). Until now, agro-hydro-meteorological assistance to end-users through seasonal forecasting has been based on purely statistical methods. With the new approach (using deterministic predictions) that is expected to be developed, resilience to climate variability and change is likely to be enhanced. We will be able to provide local characteristics such as the periods of occurrence of extreme hydrological events, their amplitude, the availability of water resources and associated margins of error.

Pros and cons or cost-benefit analysis of climate adaptation

Studies have shown that end users can benefit from climate change adaptation in terms of increased income and reduced risk through the use of seasonal forecasting despite the uncertainties associated with current forecasts. Generally, investments that prevent climate-related disasters are much lower cost than the economic and human losses caused by such disasters. One of the major shortcomings of previous hydrological forecasts (statistical approach) is that they did not meet users' expectations for assessing water resources for decision support. As part of this study, it was possible to produce quantitative hydrological forecasts on the availability of water resources at the Niger Basin scale.

Policy aspects

In the past, adaptation strategies have focused on managing crises rather than preventing them. With the increase in extreme weather events and the high cost of crisis management, public opinion has become aware of the importance of climate change adaptation measures in anticipating such events. The activity of seasonal hydrological forecasts in West Africa is already included in policies to strengthen resilience to climate change and variability. However, the previous forecasts no longer sufficiently met the expectations of increasingly demanding users and decision-makers. Thus improved forecasts will better meet existing policies.

AGRHYMET Regional Centre


Poster displayed at the Kick–Off meeting, 7/8 September 2017, Norrköping, Sweden

Floods caused by the Niger River overflow in 2012