Sediment sampling in Large Rivers; Experiences from the Kasai River in
the Congo Basin
Abstract
Land use change due to population growth and an increase in
anthropogenic activities such as logging and mining (mostly illegal)
have led to an increase in the sediment load of the Kasai River in the
Congo River Basin. However, even with recent developments in
technologies such as remote sensing and improvements in erosion
prediction models to study sediment transport in water bodies; this
phenomenon has been little studied in this poorly gauged catchment and
the wider Congo River Basin due to lack of field-based sediment
concentration measurements required to calibrate the results of such
studies. The present study describes recently concluded field excursions
to set up a high frequent sediment sampling station on one of the major
tributaries of Congo River, the Kasai River. The station is fitted with
an ISCO 6712 automatic pumping sampler to enable high frequency
sampling. The ISCO is coupled with an OBS 501 turbidity sensor to
collect even higher frequent sediment concentration data. The site is
also fitted with other instruments to measure other hydrologic and
climatic variables such as a manual staff gauge and an automatic water
levels logger. The preliminary sampling efforts have been designed to
guide a comprehensive sediment sampling programme which is part of a
wider study to build a sediment yield model for the Congo River Basin in
order to study the impacts of sedimentation on hydropower planning.