DECIDAID

The annual flooding of the Inner Niger Delta is the key driver that governs the ecology, livelihoods and ecosystem services of the area. Every year a vast area is being inundated by the annual floods. In the rainy season the Niger River and its tributaries are filled by the rains in the Guinean highlands, before flowing eastwards towards Mali. This means that any interventions upstream, hydropower, irrigation or other use (see hydrological infrastructure), have major impacts on the discharges in the rivers and hence, the flood patterns of the Inner Niger Delta. Several studies have been carried out to investigate the impacts of such interventions on the flood patterns and ecosystem services in the Delta. [links to reports] Based on the results of these studies, a simplified online tool called Decidaid has been developed that shows these impacts in maps and graphs.

The user can select a key parameters that reflect the realization of the Moussako (or Fomi) dam and the expansion of Office du Niger. Based on these choices, the maps showing inundated area and the graphs showing ecosystem services are automatically updated to show the impacts of these choices. To see how the Decidaid tool works, please make your selection in the dropdown menus and have a look at the maps and graphs below.

The maps below show inundation patterns in the Inner Niger Delta based on the chosen parameters for water management. Two scenarios are shown: a situation that is representative for a very dry year (1984) and one for a wet year (1967).

Inundation of the Inner Niger Delta depends on the discharge in the Niger and Bani Rivers. The graphs below show the changes in annual discharge compared to the normal situation (business as usual). The left graph shows the percentage change that is expected in a wet year, average year and dry year. The graph on the right shows the discharge values (m3/s) for the chosen scenario compared to business as usual, again for wet, normal and dry years.

Similar to the changes in discharge, the graphs below show how these changes are reflected in the inundated area of the Inner Niger Delta.

The production of ecosystem services in the Inner Niger Delta is largely dependent on inundation patterns and water availability in the Delta. To visualize the impacts of the chosen water management scenario on ecosystem services, the graphs below show changes in the production of 1) rice, 2) dry cereals, 3) fish (measured as fish traded on the markets of Mopti) and 4) livestock. Similar to the graphs above, these patterns are shown for a wet year, average year and a dry year.

More details on the impacts of water management in the Upper Niger Basin can be found in several background documents:

DECIDAID

BAMGIRE project