Abstract:
Anthropogenic factors associated with
damming and water abstraction, and the resultant
environmental pressures, are reviewed in six African
river catchments using records and forecasts of climatic,
demographic, and land-use change. Changes in
the states of the flow regime through catchment
drainage systems to the coastal sea are considered in
conjunction with climate change and other humaninduced
pressures. The impacts of these changes on
downstream and coastal environments and their
communities are described in past, present, and future
perspectives. Linkages between the issues and the
pressures of damming and water abstraction are appraised
and scientific, policy, and management responses
proposed aimed at remedying existing and
perceived future negative impacts. The study proposes
that there is a need to integrate catchment and
coastal management to account for the whole water
flow regime together with its human dimensions.
Management priorities relating to the operation of
existing damming and abstraction schemes and planning
of future schemes include the following: consideration
of ways in which water discharges could be
adjusted to provide improvements in downstream and
coastal environmental and socioeconomic conditions;
addressing the problem of sediment trapping impacting
on the sustainability of dam reservoirs; and
assessment of downstream and coastal impacts of
future schemes in the light of climate change forecasts.
