Water losses in the inner delta of the River Niger: water balance and flooded area

The inner delta of the River Niger receives runoff from both the River Niger and the River Bani (249 000 km(2)) and is divided into a northern part (15 000 km(2)) and a southern part (58 000 km(2)). The average input and Output discharges are approximately 1490 and 900 m(3) s(-1) (1955/1996), respectively. The annual average water loss is approximately 40% (24-48%). The losses are greater in the northern (10.5 km(3)) than in the Southern delta (8.2 km(3)), but this situation was reversed in 1984. The correlation between the output and input discharges is high for the northern part of the delta, but very low for the southern part, where the chan,,e in flooded area is likely to be limited. The average flooded area, calculated using a method based oil the hydrological balance, is estimated to be about 10 000 km(2) (north) and 14 000 km(2) (south), which is consistent with the estimates provided by the previous authors. Copyright (C) 2009 John Wiley & Sons, Ltd.