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91.
In many European cities, urban gardens are seen as increasingly important components of urban green space networks. We adopt an ecosystem services framework to assess contributions of urban gardens to the quality of of their users. First, we identify and characterize ecosystem services provided by urban gardens. Secondly, we assess the demographic and socioeconomic profile of its beneficiaries and the relative importance they attribute to different ecosystem services. Next we discuss the relevance of our results in relation to critical policy challenges, such as the promotion of societal cohesion and healthy lifestyles. Data were collected through 44 semi-structured interviews and a survey among 201 users of 27 urban gardens in Barcelona, Spain, as well as from consultation meetings with local planners. We identified 20 ecosystem services, ranging from food production over pollination to social cohesion and environmental learning. Among them, cultural ecosystem services (non-material benefits people derive from their interaction with nature) stand out as the most widely perceived and as the most highly valued. The main beneficiaries of ecosystem services from urban gardens are elder, low-middle income, and migrant people. Our results about the societal importance of urban gardens were deemed highly relevant by the interviewed green space planners in Barcelona, who noted that our data can provide basis to support or expand existing gardening programs in the city. Our research further suggests that ecosystem services from urban gardens can play an important role in addressing several urban policy challenges in cities, such as promoting stewardship of urban ecosystems, providing opportunities for recreation and healthy lifestyles, and promoting social cohesion. We conclude that urban gardens and associated ecosystem services can play an important in urban policies aimed at enhancing quality of life in cities, particularly if access to their benefits is expanded to larger segments of the population. 相似文献
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ABSTRACT: Access to clean and sufficient amounts of water is a critical problem in many countries. A watershed approach is vital in understanding pollution pathways affecting water resources and in developing participatory solutions. Such integration of information with participatory approaches can lead to more sustainable solutions than traditional “crisis‐to‐crisis” management approaches. This study aims at applying a watershed based joint action approach to manage water resources. Since most watersheds have urban and rural sources of pollution and a wide disparity in access to and use of water, alternative solutions need to take an integrated approach through cooperative actions. An institutional model was applied to seven subwatersheds in Honduras to evaluate various sources and effects of water contamination and water shortages. Two specific pathways of water resources degradation were studied (contamination from coffee pulp manufacturing and urban nonpoint sources) to develop alternative solutions that mitigate downstream impacts of access to clean water. A locally driven joint mechanism to reuse coffee pulp in farming systems is proposed. Such an institutional solution can maximize benefits to both farms and the coffee pulp industry. A combination of education and investment in sanitary facilities in urbanizing areas is proposed to minimize urban sources of water contamination. 相似文献
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The release of biochar colloids considerably affects the stability of biochar in environment. Currently, information on the release behavior and suspension stability of biochar colloids in real soil solutions is scarce. In this study, 20 soils were collected from different districts in China and the release behavior of biochar colloids and their suspension stability in soil solutions were systematically examined. The results showed that both pyrolysis temperature and biomass source had important effects on the formation of biochar colloids in soil solutions. The formation amount of biochar colloids from low pyrolysis temperatures (400 °C) (average amount of 9.33–16.41 mg/g) were significantly higher than those from high pyrolysis temperatures (700 °C) (average amount of less than 2 mg/g). The formation amount of wheat straw-derived biochar colloids were higher than those of rice straw-derived biochar colloids probably due to the higher O/C ratio in wheat-straw biochar. Further, biochar colloidal formation amount was negatively correlated with comprehensive effect of dissolved organic carbon, Fe and Al in soil solutions. The sedimentation curve of biochar colloids in soil solutions is well described by an exponential model and demonstrated high suspension stability. Around 40% of the biochar colloids were maintained in the suspension at the final sedimentation equilibrium. The settling efficiency of biochar colloids was positively correlated with comprehensive effect of the ionic strength and K, Ca, Na, and Mg contents in soil solutions. Our findings help promote a deeper understanding of biochar loss and stability in the soil-water environment. 相似文献
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城市污水处理项目BOT融资风险分析及保障措施 总被引：2，自引：0，他引：2
随着城市建设的飞速发展,城市生活污水和生产废水的排放量也在不断增大,加快城市污水治理工程项目建设已成为亟待解决的重大问题.城市污水处理项目属于城市基础设施,在具有极大社会效益和环境效益的同时,却基本没有经济效益.而污水处理项目的建设、运营都需要大量资金投入,实践证明BOT融资可以解决这一难题.通过对污水处理项目BOT融资的风险进行分析和研究,提出切实可行的控制保障措施,为项目公司投资城市污水处理厂BOT项目提供决策依据,并为解决当前城市污水处理融资建设的难题提供思路. 相似文献
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本文分析了21世纪城市环境发展所面临的各种挑战，并进一步指出了水资源短缺和水环境污染是21世纪城市环境的最大挑战者和威胁者。在此基础上，提出了解决的对策措施。 相似文献
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