Effects Of Climatic Variability On The Hydrological Regime Of Niandan Guinea Republic

From the beginning of the twentieth century to the present day the water resources of the Niger river Basin have undergone major changes in relation to the significant climatic variations recorded in West Africa. This situation has resulted in a decrease in the water quality of the watercourses in the basin. The present study proposes to study the effects of the variation of the rainfall regime of the Niandan basin on the flow of the Niandan river which is a tributary of Niger. In this work the method of the trace analysis was used to highlight during the period from 1961 to 2009 the decay of the average rainfall of upstream 1968 mm downstream 1467 mm of the Niandan. Regarding the determination of the effects of climate variability on the water resources of the Niandan basin this work has proved that the flow is highly sensitive to downstream rainfall variations with a trend in rainfall and flow. on the decline. In the south it has been shown that although Niandan water supply comes mainly from rainwater the rainfall is not sufficient to satisfactorily explain all the changes in Niandan flow regime.