This brochure has been developed for the Water for Food and Ecosystems programme on behalf of the 3rd World Water Forum

Full self-sufficiency in cities is a major concern. Cities import resources for food, water and energy security. They are however key to global sustainability, as they concentrate a rapidly increasing and urbanising population (or number of consumers). In this paper, we analysed the dependency of urban inhabitants on the resource water for food consumption, by means of Dutch cities. We found that in extremely urbanised municipalities like Amsterdam and Rotterdam, people eat more meat and cereals and less potatoes than in other Dutch municipalities. Their current water footprint (WF) related to food consumption is therefore higher (3245l/cap/day) than in strongly urbanised cities (3126l/cap/day). Dutch urban citizens who eat too many animal products, crop oils and sugar can reduce their WF (with 29 to 32%) by shifting to a healthier diet. Recommended less meat consumption has the largest impact on the total WF reduction. A shift to a pesco-vegetarian or vegetarian diet would require even less water resources, where the WF can be reduced by 36 to 39% and 40 to 42% respectively. Dutch cities such as Amsterdam have always scored very high in international sustainability rankings for cities, partly due to a long history in integrated (urban) water management in the Netherlands. We argue that such existing rankings only show a certain – undoubtedly very important – part of urban environmental sustainability. To communicate the full picture to citizens, stakeholders and policy makers, indicators on external resource usage need to be employed. The fact that external resource dependency can be altered through changing dietary behaviour should be communicated.

The present paper reports on the results of a long-term field study on the simultaneous influence of 2 environmental factors (temperature and food supply) on annual growth rates in the tellinid bivalve Macoma balthica. For >30y (1978–2009) we monitored twice-annually the weight changes of soft parts of individuals of known age at several permanent sampling stations located at Balgzand, an extensive (50km2) tidal flat area in the western Dutch Wadden Sea. Monthly data were available on mean water temperature and chlorophyll a (chl a) concentration from a nearby site in the main tidal inlet. Mean individual ash-free dry weights at ages of nearly 1 and of nearly 1.5y were assessed in February/March and in August, respectively. Such weights show a consistent annual pattern: they increase between late winter and early summer to decline for the remainder of the year. Annual multi-station means of the spring/summer individual weight gains were higher as chl a concentrations in the water had been higher and water temperatures had been lower for the growing season. These correlations proved to be stronger at sampling sites that were situated low in the intertidal zone close to the main tidal stream than at those high in the intertidal near the coast (where M. balthica obtain their food primarily by deposit feeding on benthic material). At the low off-shore sites, suspended algae are available for longer daily periods and their concentrations in flood water may be less depleted by grazers. The negative correlation between weight gain and water temperature may have been primarily based on the shortening of the M. balthica growing seasons in warm summers. We conclude that the present simultaneous trends of global warming and declining stocks of pelagic algae may affect M. balthica in the Wadden Sea in a similar, negative, way.

The Food-Energy-Water (FEW) nexus for urban sustainability needs to be analyzed via an integrative rather than a sectoral or silo approach, reflecting the ongoing transition from separate infrastructure systems to an integrated social-ecological-infrastructure system. As technology hubs can provide food, energy, water resources via decentralized and/or centralized facilities, there is an acute need to optimize FEW infrastructures by considering cost-benefit-risk tradeoffs with respect to multiple sustainability indicators. This paper identifies, categorizes, and analyzes global trends with respect to contemporary FEW technology metrics that highlights the possible optimal integration of a broad spectrum of technology hubs for possible cost-benefit-risk tradeoffs. The challenges related to multiscale and multiagent modeling processes for the simulation of urban FEW systems were discussed with respect to the aspects of scaling-up, optimization process, and risk assessment. Our review reveals that this field is growing at a rapid pace and the previous selection of analytical methodologies, nexus criteria, and sustainability indicators largely depended on individual FEW nexus conditions disparately, and full-scale cost-benefit-risk tradeoffs were very rare. Therefore, the potential full-scale technology integration in three ongoing cases of urban FEW systems in Miami (the United States), Marseille (France), and Amsterdam (the Netherlands) were demonstrated in due purpose finally.

The Food-Energy-Water (FEW) nexus for urban sustainability needs to be analyzed via an integrative rather than a sectoral or silo approach, reflecting the ongoing transition from separate infrastructure systems to an integrated social-ecological-infrastructure system. As technology hubs can provide food, energy, water resources via decentralized and/or centralized facilities, there is an acute need to optimize FEW infrastructures by considering cost-benefit-risk tradeoffs with respect to multiple sustainability indicators. This paper identifies, categorizes, and analyzes global trends with respect to contemporary FEW technology metrics that highlights the possible optimal integration of a broad spectrum of technology hubs for possible cost-benefit-risk tradeoffs. The challenges related to multiscale and multiagent modeling processes for the simulation of urban FEW systems were discussed with respect to the aspects of scaling-up, optimization process, and risk assessment. Our review reveals that this field is growing at a rapid pace and the previous selection of analytical methodologies, nexus criteria, and sustainability indicators largely depended on individual FEW nexus conditions disparately, and full-scale cost-benefit-risk tradeoffs were very rare. Therefore, the potential full-scale technology integration in three ongoing cases of urban FEW systems in Miami (the United States), Marseille (France), and Amsterdam (the Netherlands) were demonstrated in due purpose finally.