The water footprint and virtual water exports of Spanish tomatoes

D. CHICO et al. 21FIGURE 3. Average green, blue and grey water footprint of Spanishtomato (l/kg)Source: Own elaboration.There are important differences in the volume, type, andpurpose of the production between the different productionprovinces which derive in different water footprint of tomato.Figure 5 summarizes the average green, blue and greywater footprint (l/kg) in all the Spanish provinces in decreasingorder.As shown, the water footprint varies significantly betweenthe different provinces, and so does the proportion ofthe green, blue and grey components. These differences maybe due to the predominant production system (open-airrainfed or irrigated vs. covered) in the province, yields obtainedand climate parameters (precipitation and atmosphericevapotraspiration demand). In general, we can seethat the grey water footprint is the main source of variability,whereas the green water footprint is in general termsrather low.