Dimensión política y de gestión de la Huella Hídrica

El ciclo hidrológico proporciona anualmente 110,000 Km3 en forma de precipitaciones de lluvia y nieve (L'Vovich et al., 1990). Globalmente, el 37% de esas precipitaciones se destina a alimentar ríos, acuíferos, lagos y otros sistemas acuáticos, mientras que el 63% restante, se almacena en la reserva de agua del suelo y contribuye a mantener la productividad primaria de los sistemas agrícolas y forestales. Según las distintas estimaciones, el volumen de agua que actualmente se extrae de los sistemas acuáticos para uso humano a escala global varía entre 3100 y 4400 Km3 (Postel et al., 1996; Rosegrant et al., 2002; Falkenmark y Rockström, 2004; Oki y Kanae 2006; Gleick et al., 2008). Teniendo en cuenta que la cantidad de agua que puede ser captada de forma sostenible de estos sistemas es de aproximadamente 10.200 Km3 (Postel et al., 1996), la apropiación actual de este recurso representa en torno al 31 y 44%

Urbanization, socio-economic changes and population growth in Brazil: dietary shifts and environmental implications.

Population growth, economic globalization, improving living standards and urbanization are causing important changes in the global food system and modifying the dietary habits in many parts of the world (Molden, 2007; Godfray et al., 2010). The nutritional transition (linked to the development of countries and the increasing wealth of its population) implies a shift away from traditional staple food such as roots and tuber vegetables and a rise in consumption of meat and milk products, refined and processed foods, as well as sugars, oils and fats (Ambler-Edwards et al., 2009). The contemporary food system puts significant pressure on natural resources, especially on land and water, because the growing food demand pushes the agricultural frontier beyond, causing large impacts on ecosystems (Ambler-Edwards et al. 2009: 11-18). Also, the trend towards richer diets in animal proteins and processed food adds further pressure on the environment, since it requires larger amount of water and land to be produced (Allan, 2011; Mekonnen and Hoekstra, 2012)

Evaluating the Water Footprint of the Mediterranean and American Diets

Global food demand is increasing rapidly as a result of multiple drivers including population growth, dietary shifts and economic development. Meeting the rising global food demand will require expanding agricultural production and promoting healthier and more sustainable diets. The goal of this paper is to assess and compare the water footprint (WF) of two recommended diets (Mediterranean and American), and evaluate the water savings of possible dietary shifts in two countries: Spain and the United States (US). Our results show that the American diet has a 29% higher WF in comparison with the Mediterranean, regardless of products? origin. In the US, a shift to a Mediterranean diet would decrease the WF by 1629 L/person/day. Meanwhile, a shift towards an American diet in Spain will increase the WF by 1504 L/person/day. The largest share of the WF of both diets is always linked to green water (62%?75%). Grey water in the US is 67% higher in comparison with Spain. Only five products account for 36%?46% of the total WF of the two dietary options in both countries, being meat, oil and dairy products the food items with the largest WFs. Our study demonstrates that adopting diets based on a greater consumption of vegetables, fruits and fish, like the Mediterranean one, leads to major water savings

The Extended Water Footprint and illegal groundwater use in the Upper Guadiana Basin (Spain)

Tablas de Daimiel National Park is located in the Upper Guadiana Basin and represents one of the largest and most important wetlands in Europe. The long term ecological integrity of this wetland is inherently associated with the maintenance of a shallow groundwater table, namely the Western Mancha aquifer (WMA) or Aquifer 23. The intensive use of groundwater, mainly for irrigation, has led over the last decades to deep socio‐economic changes. Such intensive use has also lowered the water table of Aquifer 23, drastically reducing the flooded area of the wetland and threatening its ecological integrity. A number of plans and measures have been developed and implemented since the declaration of overexploitation of Aquifer 23 in the year 1987. The most recent one is the Special Plan for the Upper Guadiana (SPUG), approved in 2008. This Plan is the main measure to comply with achieving the objective of good quantitative and qualitative status required under the Water Framework Directive (2000). This paper offers a new type of integrated analysis which allows assessing under a common lens the physical, economic and social dimensions of groundwater use in the area. The first objective is to calculate the groundwater footprint of agricultural production in the Upper Guadiana basin and its evolution during 2000‐2008. For this purpose, we have applied the Extended Water Footprint (EWF) methodology ‐a novel approach based on the classical Water Footprint (WF) approach‐ that includes an assessment of the water productivity from an economic and social perspective. Compared to the classical WF, the EWF allows for a more complete overview of the sector, providing new insights for policy decisions (e.g. to define options and possibilities on water re‐allocation in order to achieve both better ecosystem conservation and social equity). The second objective is to use the EWF to compare the existing authorized and non‐authorized or illegal use of water. This allows us to discuss current initiatives by public authorities in relation to the existing frame of water right

The Spanish water ?pressure cooker?: Threading the interplay between resource resilient water governance outcomes by strengthening the robustness of water governance processes.

This paper uses the metaphor of a pressure cooker to highlight how water problems in Spain are highly geographical and sectorial in nature, with some specific hotspots which raise the temperature of the whole water complex system, turning many potentially solvable water problems into ?wicked problems?. The paper discusses the tendency for water governance to be hydrocentric, when often the drivers and in turn the ?solutions? to Spanish water problems lie outside the water sphere. The paper analyzes of the current water governance system by looking at water governance as both a process, and its key attributes like participation, trans- parency, equity and rule of law, as well as an analysis of water governance as an outcome by looking at efficiency and sustainability of water use in Spain. It concludes on the need to have a deeper knowledge on the interactions of water governance as a process and as an outcome and potential synergies and arguing that water governance is an inherently political process which calls for strengthening the capacity of the system by looking at the interactions of these different governance attributes

Water for Food Security and Wellbeing in Latin America: Status and Challenges in a Globalized World.

Water for Food Security and Wellbeing in Latin America and the Caribbean. Side Event organizado por el OA en colaboración con el Centro del Agua de América Latina y el Caribe y el Tecnológico de Monterrey. World Water Week Stockholm, 2 September 2013

The role of land and water for trade and food production in Latin America: Environmental trade-offs of agricultural intensification versus extensification

One of humanity’s major challenges of the 21st century will be meeting future food demands on an increasingly resource constrained-planet. Global food production will have to rise by 70 percent between 2000 and 2050 to meet effective demand which poses major challenges to food production systems. Doing so without compromising environmental integrity is an even greater challenge. This study looks at the interdependencies between land and water resources, agricultural production and environmental outcomes in Latin America and the Caribbean (LAC), an area of growing importance in international agricultural markets. Special emphasis is given to the role of LAC’s agriculture for (a) global food security and (b) environmental sustainability. We use the International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT)—a global dynamic partial equilibrium model of the agricultural sector—to run different future production scenarios, and agricultural trade regimes out to 2050, and assess changes in related environmental indicators. Results indicate that further trade liberalization is crucial for improving food security globally, but that it would also lead to more environmental pressures in some regions across Latin America. Contrasting land expansion versus more intensified agriculture shows that productivity improvements are generally superior to agricultural land expansion, from an economic and environmental point of view. Finally, our analysis shows that there are trade-offs between environmental and food security goals for all agricultural development paths

Replenishing the Indus Delta through multi-sector transformation

The Indus River Basin (IRB) is a severely water-stressed and rapidly developing home to an estimated 250 million people in South Asia. An acute deficit of environmental flows (EFs) in the basin’s delta negatively impacts geomorphology and surrounding ecosystems. Here, a sub-national model of the IRB’s integrated water–energy–land systems is applied to quantify multi-sector transformations and system costs for enhancing EFs to the Indus Delta. The results show that increasing the average outflows from the basin relative to historical policy levels by 2.5 and 5 times would increase sectoral costs for upstream water users between 17–32 and 68–72% for low and high ecological potential targets. The enhanced EFs result in more energy for pumping and treating water upstream from the delta and a net increase in irrigation and energy investments. The EF policy costs are minimized by 7–14% through cooperation across countries and 6–9% through the coordinated implementation of water efficiency measures in the irrigation, conveyance, power plant cooling, and water treatment sectors. The results underscore the crucial role of a multi-sector, multi-scale collaboration in achieving EF targets in water-stressed river basins for ecosystem adaptation to climate vulnerability, restoration of the delta, and socio-economic benefits

Water and agriculture

This chapter shows the strong links between water, agriculture and the economy in Latin America and Caribbean (LAC). Both green and blue water are vital for LAC's economies and for its food security. Awareness of LAC's virtual water trade volumes and water footprints alone will not solve the local or global water problems. However, the awareness gained increases the likelihood that optimized water allocation decisions, which consider the hydrological and economical aspects of water resources, are made. • Agriculture is a significant economic sector for many LAC countries with some being major world players in the agricultural commodities world markets, such is the case for Brazil and Argentina who contribute to 13% of the global green water export. At the micro level, agriculture still plays a significant role for the food security of the population. • The consumptive water use of agricultural production was on average 1,057Gm 3 / yr for the period 1996–2005; of which, 95% corresponds to the green water footprint, whereas 5% refers to the blue component. This indicates that LAC relies heavily on green water for agricultural production, i.e. rain-fed agriculture. • Maize is a fundamental crop in Argentina, Brazil, Chile, Mexico and Peru, representing 15% of the total agricultural blue and green water footprint (773,408hm 3 /yr) and contributing to 35% of the agricultural nitrogen pollution, estimated as grey water footprint, in Argentina, Brazil, Chile, Colombia, Mexico and Peru. Only in Mexico, maize contributes 60% of the agricultural grey water footprint. • Grazing represents 24% of the total green water footprint of agriculture in these countries. The blue water consumption by the animal water supply is very significant in Argentina, Brazil, Chile, Mexico and Peru, which amounts to 13% (38,825hm 3 /yr) of the total consumption