The evaluation of the water footprint and virtual water trade has become a promising means to evaluate the sustainability of a country's 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 Spain's 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.

Zusammenfassung
1.1 General Framework In most arid and semi-arid countries, water resource management is an issue that is both important and controversial. Most water resources experts now acknowledge that water conflicts are not caused by physical scarcity but are mainly due to poor water management (Rosegrant et al. 2002; Benoit and Comeau 2005; Comprehensive Assessment of Water Management in Agriculture 2007; Garrido and Dinar 2010, among others). The scientific and technological advances of the past 50 years have led to new ways to solve many water-related conflicts, often with tools that seemed unthinkable a few decades ago (Llamas 2005; Lopez-Gunn and Llamas 2008). This study deals with the estimation and analysis of Spain's water footprint, both from a hydrological and economic perspective. Its ultimate objective is to report on the allocative efficiency of water and economic resources. This analysis can provide a transparent and multidisciplinary framework for informing and optimising water policy decisions, contributing at the same time to the implementation of the EU Water Framework Directive (WFD) (2000/60/EC). It also responds to the current mandate of the Spanish Ministry of Environment and Rural and Marine Affairs, which recently issued instructions for drafting river basin management plans in compliance with the EU Water Framework Directive, with a deadline of end of year 2009 and then every 6 years (BOE 2008).

Inhalt
Literature Review.- Methodological Approaches.- Data and Limitations.- Spain's Water Footprint.- Net Virtual-Water Flows.- Bringing the Analysis to the Policy Context.- Summary and Conclusions.