VIRTUAL WATER: A FRAMEWORK FOR COMPARATIVE REGIONAL RESOURCE ASSESSMENT

New developments in water resource allocation techniques range from local management of green water to international trade in water. A further extension of this is through the virtual water concept, which is the water required to produce a crop or product. The virtual water content of many products is now available at a national and global scale. While these calculations are meaningful in international trade debates, they are not useful to water managers since regional climatic and management conditions are highly variable. The utility of the virtual water concept at a smaller scale is illustrated by a comparison of agricultural crops in the driest and wettest agro-climatic regions in Canada. Results were compared to national and international global calculations. The calculations are highly sensitive to local conditions, and locally collected data needs to be aggregated and compared in order to be made useful to water managers and land use planners.