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Indian Ocean Climate event brings floods to East Africa's lakes and the Sudd Marsh
Author(s) -
Birkett Charon,
Murtugudde Ragu,
Allan Tony
Publication year - 1999
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl900165
Subject(s) - marsh , swamp , precipitation , wet season , wetland , hydrology (agriculture) , dry season , geography , environmental science , climatology , geology , ecology , meteorology , cartography , geotechnical engineering , biology
During an El Niño, the expected rainfall increase over most of the Lake Victoria catchment area is ∼15–25%. However, due to anomalous warming of the western equatorial Indian Ocean during 1997, strong convection developed over parts of the Horn and eastern Africa. This resulted in a much larger 20–160% precipitation excess during the “short rainy” season. Satellite radar altimetry data reveals that not only did Lake Victoria rise by ∼1.7 m, but that the rainfall event similarly affected lakes Tanganyika, Malawi and Turkana. In addition, the seasonal level minima of the Sudd marshes and Lakes T'ana and Nasser continue to increase. Such a rainfall event will have severe, long‐term consequences for the natural surface flows and storages along the White Nile. Based on the hydrological impacts of the historic 1961 East Africa event, we can expect the current high levels of Lake Victoria to be maintained for the remainder of this decade. In addition, we anticipate a major expansion of the permanent swamp regions of the Sudd marshes over the forthcoming seasons. Blue Nile flows, further enhanced by the above‐average 1998 rainfall season, can also be expected to remain high, at least until early 1999.