Hydrological model to support the countries around the Niger River

Heavy rainfall and dry spells are common in the countries surrounding the Niger River in West Africa. Researchers from SMHI in Sweden and the AGRHYMET regional centre in West Africa have jointly developed a tool which can provide a better quantification of the hydrological fluxes in the Niger River basin.

Water is an important natural resource in the Niger River basin, and is a prerequisite for e.g. the smallholder agriculture in the area.

– The populations are heavily dependent on the river and the cooperation between countries is crucial. With support of a hydrological model we can predict the hydrological situation. For example, already in the beginning of the rainfall season we can forecast the seasonal outcome, says Dr. Abdou Ali, senior hydrologist from the regional organisation AGRHYMET in Niger.

Calculation of water flows

The interaction between SMHI and researchers in Niger, Mali, and Burkina Faso has been important during the project, both to develop the model and to establish it in the region. Together they have developed an adapted version of the hydrological prediction model HYPE for the Niger River basin called Niger-HYPE.

The model can simulate the water flow in the Niger River. Moreover, the model can predict the water fluxes in the whole river basin, despite lack of observations in many areas. In addition, potential climate change impacts on the river basin can be analysed based on model simulations of past, present and future climates.

– Together we have developed and adapted the model to the dominant processes in the region. The cooperation improved the calculations and the regional capacity to handle the model and use its results. In addition, the development builds on open-source code, which enables regional experts to further develop and use the tool on their own, says Jafet Andersson, researcher within hydrology at SMHI.

The research project will finish in 2014, but both SMHI and AGRHYMET want to continue the collaboration, and an ongoing dialogue is focusing on how to operationalize the model in the region.
 

Rainfall Index West Africa
The annual rainfall season spreads from June to September. After several years with abundant rainfall, a long period of abnormally low rainfall and widespread drought started during the 1970’s. Since the middle of the 1990’s the area have had very fluctuating precipitation, with flooding as a consequence.
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Mean annual precipitation in the Niger River basin.
Mean annual precipitation in the Niger River basin (1979-2009). The area contains a large variety of climates, from the Sahara desert in the North to tropical rain forest in the south.
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