The evaluation of the water footprint and virtual water trade has become a promising means to evaluate the sustainability of a countrys water resources. This book is based on the research and results of a thorough study carried out for Spain, which serves as a leading case for a semi-arid country. The objective of this study was to assess and analyze Spains virtual water use and water footprint, differentiating the green and blue (surface and groundwater) components, both from a hydrological and economic perspective. This contributes to the water footprint and virtual water literature in several ways. By evaluating both water footprint and virtual water over time and at the provincial scale, the analysis allows for policy-relevant conclusions at the river basin level. By separating green and blue water components, and evaluating all crops at the provincial level, the study enables a finer analysis of how water footprint and virtual water vary during droughts and water shortages. The linkage between commodities trade and water scarcity was explored to determine the extent to which virtual water trade has the potential to deal with water-stressed periods. The analysis contained in this study includes both market and non-market dimensions and will appeal to researchers in both resource economics and hydrology as well as policy-makers concerned with water-related issues.