Abstract:
The Gamo Highlands in Ethiopia are characterized by complex topography and lakes.
These modulate the mesoscale and synoptic scale weather systems. In this study, we analyzed the
temporal and spatial variations in weather as function of topography and season and their impact on
potato crop growth. To determine how crop growth varies with elevation, we installed a network of
six automatic weather stations along two transects. It covers a 30-km radius and 1800-m elevation
difference. We conducted a potato field experiment near the weather stations. We used the weather
observations as input for a crop model, GECROS. Data analysis showed large differences between
weather in February and May. February is more dominated by mesoscale circulations. The averaged
February diurnal patter shows a strong east to southeast lake breezes and, at night, weak localized
f
lows driven by mountain density flows. In contrast, in May, the synoptic flow dominates, interacting
with the mesoscale flows. The GECROS model satisfactorily predicted the elevational gradient in
crop yield. Model sensitivity experiments showed that belg-averaged precipitation distribution gave
the highest yield, followed by exchanging May weather observations with April
