Hydrology and geochemistry of the Congo river system

Abstract

This study is a review of the hydrological and geochemical characteristics of the Congo basin. The temporal and spatial variations of the water cycle balance were studied to determine the hydroclimatic fluctuations since the beginning of this century and to understand the hydrological regime of the Congo River. The amounts of matter discharged out of the Congo basin to the Atlantic Ocean are estimated using available data on suspended and dissolved materials transported by the Congo River. The river organic output represents only a minor flux compared to the cycle organic matter within the basin. The average chemical erosion rate of the Congo basin is calculated, after correction for the atmospheric and biospheric inputs (cations and CO2), from the river loads. The chemical composition of surface waters wich drain the different rock types allows to calculate the contribution of each geologic unit to the river output and to estimate the mean weathering rate of the various rock types.