5.0 Conclusions
The WaPOR products for Africa and the Middle East provide the highest
resolution continuous near-real-time products available so far to
monitor ETIa. Current validation efforts need to be continued and
intensified to confirm the suitability of these products for various
uses. However, significant issues with the sparseness of available
ground-truth measurements make direct validation to in-situ,
insufficient as a sole means to validate the ETIa product over
continental Africa. To compensate for insufficient ground-truth
locations, we added physical consistency and level consistency checks as
part of the validation analyses. Results suggest that the ETIa-WPR are
responsive to general trends associated with climate types. In dry
irrigated areas, WaPOR appears to be overestimating ETa, particularly
the coarse resolution. Analysis of the intermediate data components
provide insights into some of the possible causes of the over- and
underestimation of ETI-WPR, which appear to be primarily driven by an
overestimation of the SMC which is driving overestimation of
evaporation. The WaPOR database shows promising results, with an overall
MAPE of 29-31% from local to basin scale, particularly considering it
presents a continental almost near real time open-access dataset.
Further validation activities are suggested as new ground-data become
available, particularly in cropped and irrigated areas.