Accounting for a scarce resource: virtual water and water footprint in the global water system

Effective water management and governance at all geographical levels can only be designed based on good quality information and thorough understanding of it. The accounting for water resources from virtual water (VW) and water footprint (WF) perspectives can generate information about water uses in production processes and flows of VW associated with the trade of commodities. There have been a large number of studies on VW and WF since the advent of the two concepts. The recent literature has seen an increase in explicit elaboration of local, regional and national water uses in the context of global economic and water systems. More sophisticated and systematic approaches, such as input-output (IO) models and Life Cycle Assessment (LCA) tools, have been employed to facilitate the analysis of complex interconnections of water uses across system boundaries and environmental impacts incurred. However, limitations and shortcomings remain in the current VW and WF studies with regard to policy relevance, data accuracy, methodological approaches and conceptual consistency. Further efforts are required from the scientific community to tackle these problems in order to enhance the usefulness of the concepts and the data generated for water resources management and governance at all geographical levels which are intrinsically connected through VW trade.