Inner Niger Delta - Ecology

Ecology

The Niger inland Delta lies in the Sahelian zone, and has an ecosystem that is largely dependent on the amount of flooding it receives.

Precipitation in the water basins of the upper course of the Bani and Niger rivers makes for rising waterlevels downstream. The rising water floods varying parts of the low-level delta area, with the water rise determined by the amount of rain fallen upstream. This in turn, is influenced by the northward movement of the Intertropical Convergence Zone. A delay exists between the peak amount of precipitation and the maximum water level in the inland delta area. While the wet season lasts three months from July till September, the western and southern edges of the delta area are not flooded until early to mid-October. Consequence is that parts of the delta are flooded while the dry season is well under way. Note that only the lowest patches are flooded annually: higher elevations receive flooding in more intermittent periods due to the changing degrees of waterlevel rises. This division in roughly three zones (flooded, periodically flooded and not-periodically flooded), makes for patches that vary in their nature according to their proximity to a main body water and elevation.

In turn, this strongly affects land use in and around the inland delta, as human impact is driven by agriculture, both irrigated and rainfed, grazing and browsing of herds and flocks and the collection of wood for fuel, all dependent on the availability of water.