Assessment of characteristics of meteorological droughts and their impacts on streamflow droughts in Kilombero sub-basin

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Date
2013
Journal Title
Journal ISSN
Volume Title
Publisher
University of Dar es Salaam
Abstract
The study assessed characteristics of meteorological droughts and their impacts on streamflow droughts in Kilombero sub-basin. Seasonality displayed unimodal pattern with rainfall received mainly in period December-May though nature of rainfall mechanisms results into DJF and MAM seasons while June-November period is dry season. SPI and SDI were used for meteorological and hydrological droughts analysis respectively. Met-hydro drought linkage followed visual analysis of plots of SPI and SDI and analysis of BFI and Q95 as streamflow affecting factors. Meteorological droughts were predominantly moderate/severe and seasonal occurring at high frequency in DJF than MAM and rarely for both. Hence droughts duration ranges 2-6 months and widely covered North east part of the sub-basin. Severe and extreme hydrological droughts occurred in 1956/57-1960/61 mostly in large rivers while moderate/severe droughts occurred in 1976/77, 1981/82, 1994/95 and 2003/04-2005/06 in small rivers the hydro droughts duration ranges 6-12 months despite of droughts persistence in 1956/57-1960/61. Met-hydro linkages observed in 1975/76, 1976/77, 1980/81, 1994/95, 2003/04 and hardly related in other analysed years. Severe/extreme droughts of 1956/57-1960/61 characterised larger rivers and were moderate or absent in smaller rivers despite of comparable average BFI and Q95. An extensive study is recommended to understand in detail all hydrological processes involved in sub-basin and applying a hydrological modelling to quantify the amount of streamflow’s within the sub-basin.
Description
Available in printed form, East Africana Collection, Dr. Wilbert Chagula Library, Class mark (THS EAF QC929.D8T34M34)
Keywords
Droughts, Meterogical droughts, Streamflow droughts, Hydrological droughts, Kilombero sub-basin, Tanzania
Citation
Makungu, E. J (2013) Assessment of characteristics of meteorological droughts and their impacts on streamflow droughts in Kilombero sub-basin, Master dissertation, University of Dar es Salaam. Dar es Salaam.