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.