3.1.1. GPCC vs CRU based precipitation estimates
The Congo basin precipitation estimates and its uncertainties are
important issues that sometimes results in polarized debates and
divergent opinions amongst climate researchers who have worked in the
region (Ndehedehe et al., 2019). The challenging terrain, environmental
conditions, and limited gauge observations in the Congo basin are some
reasons for the poor understanding of precipitation estimates. Although
time constraints (i.e., availability of historical observations) was a
deciding factor in our choice of precipitation, as earlier mentioned
(Section 2.1), the error variance in GPCC and CRU is significantly less
compared to satellite products. Apart from disturbance of ecological
assets and alteration to the Congo forest through prolonged drought and
deforestation, the influence of topography on the Central African
hydrology and its neighbouring East African countries cannot be
overlooked. As with the influence of topographical variability and gauge
density on precipitation products in the surrounding East African
countries (Agutu et al., 2020), the Rift valley highlands in East Africa
was earlier identified as an important driver of considerable anomaly in
precipitation over the Congo basin (Bell et al., 2015). But the
availability of in situ data to improve process-based knowledge on these
drivers and monitor these conditions, including land surface conditions,
local water recycling activity and contributions from oceanic hot spots
is an issue for the Congo basin. It is true that a history of
hydrological measurement exists in the Congo basin (Alsdorf et al.,
2016).