| dc.description.abstract | Alluvial deposits are features resulting from river deposition. They consist of gravel, sand
and silt particles, formed on the lower course of a river. Deposition of sediments at the
lower course of a river increases because of a decrease in the river flow and hence a
reduction in the competence of the flow. This study focused on the lower course of River
Kuja, approximately 5 km from the river mouth and 4 km away from the river channel on
both sides of the floodplains. Continuous accumulation of sediments on the river channel
makes the channel to become shallow in depth, thereby forcing water in the channel to go
over the river bank, into the floodplains, carrying the river load into the farmlands and
hence, an increase in soil fertility. Floods emerging from over bank flow can cause erosion
of fertile soil along steep river banks, destroying crops, livestock and drowning homesteads
of the inhabitants. The objectives of the study were to: identify types of alluvial deposits on
lower course of River Kuja; determine the effects of alluvial deposits on the physical
environment; find out the effects of alluvial deposits on socio-economic activities on lower
course of River Kuja. A sample size of 384 households was obtained from a total of 20,000
households from the study area by the use of simple random sampling technique. Primary
data was collected through Household Survey, Focused Group Discussions, Key Informant
Interviews, Observation and Photography. Secondary data was collected by reviewing
documented literature including reference books and from the internet. Quantitative data
were analyzed by using descriptive statistics such as percentages. The study identified river
channel deposits, the river bank and the floodplains deposits. Alluvial deposits can cause
deep river channels to become shallow, cause over bank river flow into the floodplains,
pools of stagnant water, soil erosion on steep river valley, drowning of homesteads and
displacement of inhabitants from the floodplains. On socio-economicactivities alluvial
deposits affects crop farming, livestock keeping, fishing and trading activities. The results
indicated that alluvial deposits are found on the channel, on the river bank and on the
floodplains, where they affect the physical environment and socio-economic activities.
Research study recommends that the roads leading to the river bank be improved, to enable
trucks to reach the river bank and collect coarse sand from the river channel; deepen the
channel and hence reduce over bank river flow that causes floods on the floodplains,
encourage cultivation of farms along the contours, give early warning to the inhabitants to
vacate areas prone to floods. This will reduce losses incurred when their properties are
destroyed by the floods and finally encouraging the farmers, fishermen and traders to join
co-operative societies to help them in identifying appropriate market for their produce even
during flooding events. This will discourage the farmers from selling their produce to the
middlemen who exploits them during flooding events when they are faced with limited
market. Consequently, this will help in improving the livelihood of the inhabitants and
hence, economic growth of Nyatike Division. | en_US |
