Water Footprinting for what?

Abstract

Objective. of this article is to introduce the historical situation of water footprint in relation with virtual water trade, and to discuss about the current issues on the way of estimating water footprint and communication.

Results and Discussion. Unlike carbon footprint, the location, season, origin/source, quantity, and quality including temperature and gravity potential of water withdrawals and discharge returning the used water to natural water cycle, are relevant for impact assessment of water footprint on environment. Therefore these information should be associated with inventory of the water footprint. Expressing a single value as for water footprint by integrating these aspects should not be an easy task. Any single value of water footprint should have properties such as: 1）larger water footprint means larger environmental impacts on water, 2）water footprints can be summed up, and 3）efforts to reduce water withdrawals/consumptions and to improve the water quality of waste water can be reflected on the value of water footprint.

Conclusions. The current work showed special characteristics of water footprint compared with carbon footprint. Water footprint can be utilized for the “life cycle water risk assessment” integrated with the current and future potential risk of water resources and the sustainability in the region where the water footprint is put.