The flood hazard in the lower reaches of the Sondu/Miriu river
Abstract
This dissertation is on the flood hazard on the River Sondu
floodplain which is structurally continuous with the Kano Plains in
Kisumu District. The incidence of floods has become greater in the
recent past.
First, the study attempts to establish whether the greater
incidence of flooding can be attributed to changes in river flow
characteristics and predict floods of various discharges. Second an
attempt to establish the reasons that keep people living on the floodplain
inspite of the eminent danger involved and to examine the factor!
that determine flood damage control measures known to and adopted by
individuals is made.
Hydrological data was obtained from three gauging stations on
the river whilst the socio-economic data came from interviews with
people living on the floodplain.
The hydrological data is used to produce hydrographs, rating
curves and flood-frequency curves. One-way analysis of variance is
used to test changes overtime.
The socio-economic data is used:to establish relationships
between the nature and number of adjustments to the hazard adopted by
individuals on the one hand and their levels of income and education,
sources of income and frequency of exposure to flooding on the other
It was found that whereas the discharge from the river has not
changed significantly,. lower discharges (than before) cause flooding.
This suggests that the channel capacity in the lower course of the
river has been reduced.
It was also found that continued occupance of the floodplain
is related to fishing and activities dependent on it. Analysis of the
data showed that the less educated and the poor are more reluctant to
leave the floodplain and that those people who live in the greater risk
zones know and practice more flood damage control measures.
In view of these findings it is recommended that floodplain,
managers emphasize 'within channel' and bank protection' methods of flood control and that enviromental conservation measures be enhanced
within the floodplain and in the rest of the Sondu river catchment
particularly in the highland source regions. Finally the victims need
to be involved in the fl60d control activities to give them that sense
of participation in the determination of their own destiny and the
priority in the Sondu-river floodplain should be flood-damage control
rather than flood control.
Citation
Bachelor of Science in Geology.Publisher
University of Nairobi