Virtual Water Flows - Conditions and Limitations

This study is, to our best understanding, the first comprehensive virtual water assessment of Alberta. Given the current absence of such assessments, we consider the results from this report encouraging and reasonable as an early approximation. Nonetheless, a number of limitations in our study still remain. First, the water footprint of wheat, barley and canola may be largely influenced by the lack of locally available climate, soil and management data. It is very difficult to obtain these data from the local agencies or the Internet.

Many efforts have been made but the difficulties lead to the application of such data from global database, e.g. climate data from the Climate Research Unit of the University of East Anglia in UK. Access of local data is a key for the more accurate estimation. Second, the lack of locally available information associated with the limited time does not allow estimation of water footprint of livestock products. Instead, the average water footprint of Canada was used for the calculation. Third, virtual water flows were only assessed for crop and livestock products but not for energy carriers. Energy sector is important for Alberta and virtual water flows through energy trade is interesting.

A comprehensive assessment requires a good knowledge of water use in the supply chain of energy production. Last but not least, virtual water flows between Alberta and destination countries were only assessed for crop products mainly due to the unavailability of data for livestock products.

To conclude, the data issue was more serious than expected when the research was conducted. Availability of local data will no doubt improve the accuracy of the study, but a lot of efforts are still needed to further the sharing of data.