Assessment of Virtual Water of Irrigated Agriculture, Imports, Exports and Water Footprint for Sri Lanka

Irrigated agriculture is the highest water user in Sri Lanka. Therefore, when there is an increasing demand of other sectors such as drinking, industries, environment etc., it is required to reallocate water from the irrigated agriculture sector to meet this increased demand. However, this needs to be done while ensuring the food security of the nation using the virtual water concept, which is defined as the embedded water in a product. Therefore, this study is conducted with the objective of assessing the, i) virtual water of agricultural production, ii)virtual water of food imports and exports, iii) virtualwater trade and iv) water footprint of the nation. The dataon crop water requirements, extent cultivated, imported,and exported agricultural products were collected fromsecondary sources and the analysis was made accordingto the globally accepted methodology. The annual virtualwater value of domestic production is found to be 8.13Gm3 of which paddy contributes 54.7%. The averagevirtual water value of paddy in Maha season is less thanthat in the Yala season whilst the virtual water value ofpaddy in minor schemes are higher than that in the majorschemes in both seasons implying that more water isrequired to produce 1kg of paddy in minor schemes. Thenet import of Virtual water is 3.8 Gm3 per year. The waterfootprint of Sri Lanka is 12.0 Gm3 per year with a percapita water footprint of 535.22 m3 per year. The waterrequired for domestic production is about 15.8% of thesurface runoff of the country indicating the possibility ofmeeting the food demand with the available waterresources.