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Theme: THE DEGRADATION OF WETLANDS AND ITS SOCIO ECONOMIC AND ENVIRONMENTAL IMPLICATIONS IN NDOP CENTRAL SUBDIVISION, NORTH WEST PROVINCE CAMEROON

This is another major factor which can be held responsible for wetland degradation. This factor however generates another argument if a second thought is taken on the concept of a wetland itself. Based on Ramsar classifications, the Bamendjin reservoir can be considered as a man-made wetland. Talking about the degradation of this wetland could mean looking at the negative changes that are occurring in the dam waters of the Bamendjin lake itself. Another consideration will be instead looking at the original wetlands that occupied this area before the construction of the dam and looking at the dam waters rather as a negative factor which led to the degradation of the original wetlands of this area. The second consideration will guide the orientation of this section.
Studies carried out by S.E.D.A (1974) revealed that the construction of this dam in 1972 led to considerable changes in the upper Nun valley. The dam was constructed with the aim of accumulating water during favourable periods (i.e. the rainy season) and releasing it during unfavourable dry periods. The release of this water occurs most often around January when the water level of the Sanaga is experiencing a drop. Given that the water level of the Sanaga needs to be maintained high enough to turn the turbines at Edea, the Bamendjin reservoir therefore acts as a regulator of the volume of water in the Sanaga.
The first filling-up of the dam started in 1974 and the first partial release occurred between January to February 1975. At full capacity, this reservoir contains over 1847km3 of water and in principle extends over a surface area of 333km2, although most often it attains 442 km2. The impact of this dam was so negative that Boutrais J. (1974) in his studies asked whether its construction was necessary. His argument was based on the fact that the drainage basin of the Nun was too small (2000km2) as compared to that of the R. Djerem at Mbankaou (20,000km2) and so could not sufficiently contribute as a regulator of water flow in the Sanaga.

Before the construction of this dam, the areas now occupied by water were mostly occupied by raphia palms, date palms, extensive prairies, streams and marshes. It appeared as a dense swamp forest within which several animals and birds were hunted (Deloucas 1994 and Tanteh G.C. 2005). With the construction of the dam, the whole area was flooded and all this vegetation cover was drowned. Most of the wetland vegetation died and got rotten; meanwhile a few ligneous species survived towards the edges of the lake where the depth was not too profound. However, most of these trees dried off and only exist today as dead tree stumps. Figure 16 a and b are DEMs of this region before and after the construction of the dam. The first DEM (15 a) is a representation of the area before the construction of the Dam