Assessing Spatio-temporal Changes of Ecological Water Footprint and Economic Value of Water in Tomato production at Iran

In this study, spatial and temporal changes of ecological footprint components and the economic value of virtual water of tomato crop have been estimated during the 2005 - 2017 in the producing provinces. The results showed that the average ecological footprint of water in the mentioned product is 327.2 m3/ton, which is the share of green, blue and gray water footprint is 4.6%, 83.5% and 11.95, respectively. Bushehr province (86.8 m3/ton) and Qom province (771.6 m3/ton) have the lowest and highest water footprints in Iran, respectively. The highest share of green water footprint is related to Bushehr, Southern Kerman, Mazandaran and Hormozgan provinces while the highest share of blue water footprint is related to Lorestan, Kohgiluyeh, Boyer-Ahmad and Khorasan Razavi provinces. The average economic value of virtual water in Iran is 0.78 USD/m3, which is the highest (1.68 USD/m3) and the lowest (0.29 USD/m3) in Bushehr, Kohkiluyeh and Boyer-Ahmad, respectively. The average volume of virtual water for tomato production is 3925.99 MCM per annual, of which 99% is exported annually from the Iran. The share of Qom, Guilan and South Khorasan provinces in the export of virtual water is the highest. Finally, the results of this study showed that due to water and soil limitations in Iran, ecological footprint index, virtual water volume and awareness of virtual water trade provide useful information for prioritizing tomato cultivation in susceptible areas. Therefore, it is suggested that this concept be used for the allocation of agricultural water resources and policy to stop or develop cultivation at the provincial and national scale.