Water Budgets and Droughts under Current and Future Conditions in the
Congo River Basin
Abstract
A multi-model hydrological assessment in the Congo Basin is performed to
assess water availability conditions for historical and future periods
(1913–2099). With models limited by scarce in situ observations, a
combination of GRACE satellite data and soil-moisture-based drought
indices is shown to be capable of estimating water budget, streamflow,
and drought and storage variability. Changes in land use and land cover
played a role in modifying the hydrologic responses but were found to be
within the uncertainties of other inputs, including weather, soil, and
model parameters. Seasonal and annual variability in total water storage
anomalies (TWSAs) and the modified Palmer drought severity index (MPDSI)
display a good correlation with each other. A selected set of global
climate models is used to characterize the future temperature and
precipitation patterns. It is expected that subbasin-scale variability
in future temperature and precipitation increases will result in
increased evapotranspiration, decreased runoff, and more drought events
in the Congo Basin.