The area of CATCH in this template follows the area labeled
'sub-regional window AMMA-CATCH'
in the map contained in the document at the WWW site of AMMA
(http://medias.obs-mip.fr/amma/AMMA_resume.html).
Even at this smaller scale, the region has very steep gradient of aridity, so the representativeness of energy and water quantities averaged over this region seems to be questionable.
The map in the document of AMMA shows two greater regions in addition to the 'sub-regional window'. Further discussion is needed to decide which region should be used.