The effects of lithological formations of the monotonous landscape in the Niger delta region

Abstract

The Niger Delta is an area criss-crossed by network of Rivers and streams, its distributaries flood, erode transport and shape their channels, thereby determining the surrounding land-use and soil characteristics, as well as the lithological formations. The physical characteristics of the region is classified into five ecological zones of mangrove forest and coastal vegetation, freshwater swamp forest zone, lowland rainforest, derived savannah zone. Its geomorphologic factors are composed of sediment deposits washed from the inland and the flood plain of the region has river channels such as Orashi river, whereby the stream energy directed from side to side of the river channel, results in the widening of the valleys. Also the meteorological factors as a result of rainfall excesses are determined primarily by the amount, duration, intensity and time distribution of rainfall. In the Niger Delta the mean annual rainfall ranges between 3000mm to 4000mm that results into the wide distribution of swamps within the area, while the soil factor is being influenced by the climate, vegetation, lithology (rock type) and topography, thus the lithological formations along Orashi river are essentially alluvial and friable, do not resist any erosional tendencies, but rather tend to succumb and aggravate the situation.