Abstract:
Bank erosion is one of the major sources of fluvial sediments. However,
very little is known about the bank erosion rates, channel processes and
volume of eroded sediments of tropical rivers. The study, therefore,
assessed the annual bank erosion of a tropical river in Ghana using the
erosion pin method from which estimates of annual sediment detached
into the fluvial sediment system was determined. The underlying channel,
fluvial, sub-aerial processes and soil characteristics influencing channel
stability were investigated and discussed. There is a spatial variability in
river channel processes; very active channel and bank erosion and
deposition of fluvial materials along channel walls. Bank erosion is low at
certain reaches of the rivers and channel deposition occurs at the inner
bends of meander loops. Large volumes of bank sediments were delivered
from the more eroding banks. Channel geometry, discharge/fluvial
hydraulics or processes and bank materials are the major driving forces
influencing bank erosion and deposition of river channels. Longer
timescale of erosion pin measurements involving greater number of sites
are required to get a better understanding of bank erosion rates and the
fluvial sediment budget of tropical rivers