Resumen
This special issue is a collection of recent papers in the field of Water Footprint Assessment (WFA), an emerging area of research focused on the analysis of freshwater use, scarcity, and pollution in relation to consumption, production, and trade. As increasing freshwater scarcity forms a major risk to the global economy, sustainable management of water resources is a prerequisite to development. We introduce the papers in this special issue by relating them to Sustainable Development Goal (SDG) number 6 of the United Nations, the goal on water. We will particularly articulate how each paper drives the understanding needed to achieve target 6.3 on water quality and pollution and target 6.4 on water-use efficiency and water scarcity. Regarding SDG 6, we conclude that it lacks any target on using green water more efficiently, and while addressing efficiency and sustainability of water use, it lacks a target on equitable sharing of water. The latter issue is receiving limited attention in research as well. By primarily focusing on water-use efficiency in farming and industries at the local level, to a lesser extent to using water sustainably at the level of total water systems (like drainage basins, aquifers), and largely ignoring issues around equitable water use, understanding of our water problems and proposed solutions will likely remain unbalanced.