3.2 Regional simulations
3.2.1 Irrigation signature in the PHO
Figure 7 shows simulated seasonal mean SM and sum of evapotranspiration
(ET) within the PHO averaged over the 7-year period. Depicted values
represent grid cell averages, meaning they are the weighted average of
all land uses in a given cell. During the winter months and into spring,
SM is high throughout the catchment, but with a declining gradient along
the North-South axis from the mountainous part down to the plain. ET in
the catchment is low during winter but starts to increase in spring,
revealing a discernible pattern attributed to differences in land use
(Figure 1). During the summer months, ET reaches its peak, displaying a
distinct irrigation signature with significantly higher ET values of 293
mm on average over irrigated land, as opposed to 214 mm on average in
the rest of the catchment. The pattern persists throughout autumn and is
also evident in summer and autumn SM, albeit less pronounced due to the
lower productivity of rainfed vegetation, resulting in reduced water
uptake from the soil. The subsequent analysis will focus exclusively on
the irrigated land, more specifically on apple orchards, as they account
for 91 % of the total irrigated area.