Urban agriculture and sanitation services in Accra,Ghana: the overlooked contribution

While urban agriculture has long been valued for providing food security and nutrition within cities, it contributes to many other urban services that are seldom cited as rationales for protecting or even expanding urban food production. Articulating the actual and possible contributions of urban agriculture to municipal sanitation and health services is critical for sustaining these urban farms and their functions into the future. In the context of the low coverage and performance of wastewater treatment plants in Accra, Ghana, health risk reduction measures implemented on and off farm can substitute to a large extent for this absence of conventional wastewater treatment. We estimate that Accra generates approximately 80,000,000L of wastewater per day, of which urban vegetable farms alone use up to 11,250,000L. By mitigating the health risks for farmers and consumers associated with widespread wastewater irrigation, these urban farms have the potential to significantly contribute to the city's sanitation needs. This could allow partial outsourcing of public health services from treatment plants to the farm, where wastewater is considered an asset instead of a problem. Urban agriculture could also significantly support buffer zone management along streams and rivers, resulting in a reduction of solid waste dumping and environmental pollution, but most importantly an improvement in flood control and related public health challenges. While urban agriculture is not the panacea for addressing these urban challenges, it can significantly contribute to their solution.     

The impact of information on landowners’ participation in voluntary conservation programs - Theoretical considerations and empirical evidence from an agri-environment program in Saxony, Germany

The voluntary nature of programs that pay landowners for conservation measures raises the question of what factors favor participation in such programs. This article focuses on the controversial issue of the impact of information on the participation decision. We develop a straightforward model to analyze how information affects this decision, and empirically estimate the impact of information, as well as other factors, on participation in a conservation program in Saxony, Germany. We find in our theoretical analysis that information measures may affect program participation either in a positive or negative way, whereas our estimation results indicate that the influence of the diverse information measures that have been relevant in our empirical analysis is weak. We argue, however, that information measures may nonetheless be warranted, as they allow for better informed participation decisions, thus contributing to a more optimal selection of program participants.     

西藏渔业资源保护及其利用的思考

随着渔业经济的发展,保护渔业资源和发展高效渔业已成为必然。西藏地处世界屋脊,特殊而严酷的自然环境造就了其独特而又脆弱的渔业资源,如何正确处理好渔业经济发展和渔业资源保护、利用的关系成为西藏渔业面临的主要问题。本文综述了西藏渔业资源及其保护和利用现状,评述了当前西藏渔业资源保护和利用工作中存在的突出问题,并提出了一些改进措施和建议。     

市场经济与土地利用规划--关于规划修编思路的探讨

文章从分析规划的本质和特性着手,进而阐述规划修编中的难点及其解决途径,在此基础上提出在市场经济条件下规划修编思路的构想、规划程序和规划方法。     

20世纪二三十年代贵州粮食市场和商品粮食数量分析

20世纪20、30年代贵州粮食市场的发育处于黄金时期，粮食市场数量众多，市场网络得以扩大，商品粮数量较大，贵州省成为粮食输出省份。本文试图通过对粮食市场与商品粮的分析，剖析经济社会处于重要转型时期的贵州商品经济的发展情况，说明商品经济的发展、现代交通运输业的兴起及其它因素成为市场发育的重要条件。     

水土保持在城市绿地规划设计中的应用

城市绿地的建设虽然可以在短时间改善城市植被覆盖率,提升人均绿地面积,但是其是否可以起到有效地防治水土流失的作用则是一个关键的问题。通过分析城市绿地可能发生水土流失的原因,探讨了在城市绿地中水土保持措施的布置原则,并且提出了水土保持措施的设计方法,以期为城市绿地规划设计进一步提供科学指导。     

Estimating the costs and benefits of soil conservation in Europe

Economics is about problems of choice. In erosion control, both public authorities and private land users are faced with such problems. What is the impact of erosion, both on-site and off-site, and to what extent can this impact be quantified? If we conceptualize this impact in terms of sustainability, how can we compare one type of effect against another? The former question can be answered only by natural scientists, the latter by economists and other social scientists. Weighing different aspects of sustainability requires value judgments, and economists are sometimes accused of having a jaundiced view of reality, wrongly supposing that decisions are based on rationality and denying the importance of emotion.However, let us assume that there is some mileage to be gained out of attempting to estimate the cost of erosion in an economic sense—which consists of converting the various effects into a common denominator: euros. If we can predict the impact of erosion control measures on erosion rates, we can know the benefit of these measures. The cost also needs to be calculated, not in terms of money but in terms of resources expended (which could have been used for other purposes) and in terms of possible negative impacts of erosion control (for instance, increased use of herbicides in reduced-tillage systems).There are important other considerations which economists may study. Firstly, there is the comparison of present versus future costs and benefits: how much can we sacrifice today for higher sustainability tomorrow?Secondly, there is the issue of private versus public costs and benefits: how do the goals of private land users differ from (those of?) the public good, how can this help us to predict land users’ behaviour, and what incentives would be appropriate to make them behave in such a way as to maximize the public good? Thirdly, how do we deal with uncertainty and risk?These problems loomed large in a study to support an extended impact assessment for the EU Soil Thematic Strategy, in 2005. Whereas much research has been done on erosion and its impact, much of this is on a small scale. The extent of the problem on a national, let alone a continental or a global scale, is still poorly known. The paper discusses how these problems were faced, which is not the same as saying they were resolved.     

松嫩平原湖泊湿地植物群落多样性及其保护研究

松嫩平原湖泊群是我国温带亚湿润地区低平原湖泊群,湖泊面积2750km2,湖泊率6%,是我国湖泊密度最大的地区之一,湖泊类型多样,有高等植物148种,隶属于38科77属;有16种植物群落,分属于挺水植物群落、浮叶植物群落、沉水植物群落、漂浮植物群落四大类;研究了松嫩平原湖泊湿地植物群落多样性现状,提出了生物多样性的保护对策;提出了相关的嫩平原湖泊湿地植物群落多样性保护对策。     

Household adoption behaviour of improved soil conservation: the case of the North Pare and West Usambara Mountains of Tanzania

The mountains in the northeastern part of Tanzania have been experiencing declining soil fertility and severe soil erosion due to increased cultivation and other factors attributed to population pressure. This study gives the main results of an analysis of household adoption behaviour towards the use of improved soil conservation measures. An interdisciplinary analytical framework for analyzing household adoption behaviour is presented. The framework links three components of the adoption decision process: the perception of the erosion problem, the decision to use improved conservation measures and the level of investment or effort devoted to soil conservation among adopters. Data collected from a random sample of 300 heads of households was used to estimate logit models of perception of the erosion problem and of adoption of improved conservation measures, and a Poisson regression model of effort devoted to conservation. The results show that participation in promotional activities of soil and water conservation (SWC) programmes influences the adoption decision process at all three stages. Also, ranking of soil erosion as the priority problem in agricultural production, participation in labour-sharing groups and having off-farm income influence the willingness and ability to use improved soil conservation technologies and the level of soil conservation effort.     

渔业财产权与海洋渔业资源养护制度的构建

我国海洋渔业资源面临衰竭的威胁,以政府主导型管理为手段的传统模式虽然在一定时期内起到了遏制“非法捕捞”的作用,但是在我国个人财产权法律制度不断健全的当今时代,确有必要倡导构建以私权利为核心的民间秩序,维护我国海洋渔业资源的养护制度,消除“公地悲剧”现象。创设渔业财产权概念是防止公地悲剧的最有效的措施。我国应当大胆借鉴英美法上的财产权概念,确立入渔机会的财产权属性。为此,我国《渔业法》再次修订时应当适度平衡渔业资源的财产权与执法成本之间的微妙关系。     

Synergy between urban planning, conservation of the cultural built heritage and functional changes in the old urban center—the case of Tel Aviv

The old urban center of Tel Aviv, like other urban centers in the western world, is undergoing accelerated development processes. Together with the trend towards gentrification are processes of urban renewal and infrastructure development and increasing demand for land and buildings, all of which increase the value of the land. The difference between Tel Aviv and other cities in the western world, as well as in Israel, is its young age and its quick pace of change. The old urban center of Tel Aviv is unique in that it is less than one hundred years old and is changing rapidly. Tel Aviv, which in 1909 was a small suburb of Jaffa, has evolved into an independent city, which is today the center of economic and cultural activities in Israel. Tel Aviv's short but significant history, together with its rapid changes, creates its image as an active and vivid metropolis with embedded heritage values. However, rapid development brings with it dilemmas. On the one hand, urban planners, tourists and entrepreneurs identify the center of town with its historical nucleus and heritage values. On the other hand, the rapid development and need for urban renovation are clearly in conflict with the need to preserve Tel Aviv's historical values and unique qualities. The purpose of this paper is to demonstrate that conservation of built heritage and urban development in ‘Young Tel Aviv’ can coexist and synergistically support each other, and that the historical values have economic potential, which may contribute to urban development. Heritage values can be formulated and even artificially produced to promote urban development. Although Israel has many very old cities with universal historical values, the young city of Tel Aviv is at the forefront of conservation.     

向海自然保护区芦苇湿地资源开发与丹顶鹤栖息地保护

向海自然保护区芦苇资源丰富,芦苇湿地又是丹顶鹤的重要繁殖栖息地,芦苇资源开发与丹顶鹤栖息地保护之间存在一定矛盾。2002年春季,向海湿地芦苇面积21 663hm2,芦苇总产量为13 700t,随着干旱的加剧,芦苇产量逐年降低;调查了丹顶鹤的迁徙动态及繁殖情况,探讨了芦苇资源的刈割方式对丹顶鹤的影响,不同的刈割方式对丹顶鹤繁殖的影响较大;提出了芦苇资源合理开发与丹顶鹤栖息地保护有机结合的对策。     

Harnessing sustainability,resilience and productivity through conservation agriculture: the case of likoti in Lesotho

Subsistence farmers in Lesotho have been able to boost agricultural yields and increase food production by adopting conservation agriculture. The practice, locally known as likoti, also contributes to combating soil erosion and to enhancing fertility. The socio-economic and environmental benefits help poor households to rehabilitate and strengthen their livelihood capital base and ultimately help rural communities to build system resilience in the face of widespread poverty and increasing vulnerability that affect the country. This paper discusses the major advantages associated with the spread of likoti. By drawing on primary data collected by FAO-Lesotho, it enquires into the determinants of adoption, thereby highlighting constraints and options for future up-scaling. The results show that attending appropriate training is a crucial prerequisite for the correct adoption of likoti. However, training is more effective when trainers pursue true participation and when social capital among farmers is stronger. Further important determinants of adoption are the level of education and the economic incentives provided to vulnerable households. Stronger policy and institutional support in all these areas would thus help address the cultural and resource constraints that limit the full potential of likoti to be harnessed and ultimately hinder its further spread throughout the country.     

巴西能源发展规划及油气投资环境分析

2008年12月,巴西的石油平均日产量为188万桶,位居拉美第三位,相比位居第一位的墨西哥(272万桶)和第二位的委内瑞拉(235万桶),巴西与之迥然不同的是它的石油产量正日益增长.巴西计划2020年以前使本国的石油产量增加一倍以上,并有潜力成为重要的石油出口国;随着巴西2030年国家能源发展规划的颁布和实施,更使其成为国际关注的焦点.近年来,巴西与中国的传统友谊因两国高层互访频繁而出现上升态势,使得中巴能源领域的更深一步合作成为可能.     

转变地质工作发展与服务方式的实践和建议

天津市地矿局注重加快转变经济发展方式,发挥地质工作优势,推进低碳清洁能源的开发利用创新和技术进步,紧紧依托地质工作的人才、技术和行业优势,加大清洁环保资源的勘查、研究、开发、利用。针对天津市水资源缺乏的情况,积极加强后备和应紧水源勘查。按照“两种资源,两个市场”的思路,通过实施中外合作勘查项目,以境外勘查工作为载体和平台,实施引进来和走出去战略,为天津市经济社会发展提供地质技术支撑。     

种养结合的农业生态循环模式探析

改革开放以来,中国城镇化的持续较快发展取得了巨大成就,也带来日趋严重的"城市病"和"乡村病",乡村众多青壮年为寻求更高的待遇离开农村往城市发展,而老龄化的进程使老一辈农民没有能力再进行耕作,大量土地废弃的"人地关系"失衡现象,造成生态环境的破坏和资源的极大浪费。要破解这种矛盾,必须实施"乡村振兴战略",而改善乡村生态环境是实现生态宜居和乡村振兴的重要内容。乡村振兴,首先是农业振兴,为使农村资源合理利用,进而推动城乡资源合理流动,激活乡村活力,提出"种养结合的农业生态循环模式",探讨通过优化种植养殖用地、生产生活方式的转变来进行乡村生态环境的改善,以期为未来各地区建设生态环境友好型新乡村规划设计的可持续发展提供参考。     

土地利用总体规划修编前期的主要指标测算原则与方法

在土地利用总体规划修编前期调研中,主要指标的测算是一个重点和难点,确定好主要指标测算的基本原则和实用、有效的方法对提高规划修编的质量有着非常重要的意义。对此,通过借鉴湖南省土地利用总体规划修编试点经验,并结合实际情况,提出了在测算主要指标时应遵循的原则与具体方法,试图为即将开展的土地利用总体规划修编提供参考。     

土地利用与国土规划空间优化:促节约·守红线·惠民生

文章围绕国家"十二五"规划重点战略部署,按照实现新时期国土规划独创性和有用性的基本工作要求,以土地用途管制为基本平台,构建了国土发展空间类型体系这一全新空间组织理念.将土地资源配置规模、节约集约用地效益、耕地和生态空间保护与国土开发、利用、保护和整治等重大问题进行结合,提出了土地利用与国土空间优化的新思路.     

Farmers’ intrinsic motivations,barriers to the adoption of conservation practices and effectiveness of policy instruments: Empirical evidence from northern Australia

The rate and extent of adoption of conservation practices by farmers is influenced, in principle, by characteristics of the practices and those of the farmers. Governments use policy instruments to increase the rate of adoption of practices which generate public benefits if it is deemed that privately optimal adoption rates will not lead to publicly optimal conservation outcomes. Recent nation-wide conservation programs in Australia have attracted criticism for low levels of effectiveness and efficiency. Could it be that program design has ignored key adoption factors, in particular characteristics of the target audience? If adoption is subject to personal factors, such as the motivations for farming, then it is likely that so are farmers’ responses to policy approaches and instruments. In this case study, surveys were conducted of farmers in three regions within the tropical savannas of northern Australia, where land-use systems are characterized by large-scale broad-acre beef grazing enterprises. Inter alia, these surveys collected data on graziers’ motivations, impediments to adoption of conservation practices, and perceived effectiveness of policy instruments in overcoming impediments. The research found that graziers had a very high level of conservation and lifestyle motivation and were motivated to lesser extents by financial/economic and social considerations, pointing to a strong stewardship ethic of graziers, or altruistic motif. Motivational profiles were significantly correlated with farmers’ perceptions about what constrained them from implementing conservation based management systems. Motivational profiles also explained differences in farmers’ perceptions of and stated propensity to interact with policy instruments, particularly at a regional scale and in the context of historical government interventions. On the basis of the empirical evidence presented, governments would be well advised to harness the diverse set of aspirations and motivations of farmers when designing conservation programs rather than. In particular, conservation programs need to take advantage of farmers’ stewardship ethic for maximum effectiveness and efficiency, and minimize the risk of crowding out intrinsic motivation and altruistic behaviours.     

SEA making inroads in land-use planning in Brazil: The case of the Extreme South of Bahia with forestry and biofuels

In Brazil, incorporating the environmental dimension to the planning process is a challenging process. Planning has historically been carried without considering environmental protection concerns. The country's large development projects have engendered a discussion on the feasibility of these works given the conflicts with environmental policies. The strategic environmental assessment (SEA) is a tool that has the potential to integrate the sectoral, territorial and environmental perspectives to promote sustainable development, as shown by international experience. Its use has not yet been regulated in Brazil, only been voluntary initiatives, both public and private, have been implemented. This paper presents the structure and results of the SEA of the plans to expand silviculture of eucalyptus and biofuels in the Extreme South Region of Bahia state, in the Brazilian Northeast, in a context of sectoral planning dissociated from government guidelines for land use policy and environmental protection. It portrays a practical case of methodological proposal for the use of socio-environmental criteria to establish limits for land occupation by monocultures, for each of the municipalities of the study region, according to their specific climate, soil, relief and environmental preservation characteristics. Various alternatives were identified to ensure areas with greater productivity for small family farming and areas with potential for preservation. SEA helped to a better understanding of the effects of the expansion of the planting areas in each alternative, which was essential to help all stakeholders visualize the consequences of their strategies. Consequently, as results the SEA outlined a series of guidelines and restrictions for the various levels of government and the production sector. For instance, SEA suggested for Federal, State and Municipality governments that areas with better soil and climate conditions could be reserved for public policies to incentive the diversification of the uses of the territory, such as food production. SEA also suggests the adoption of incentive programs to establish multiple-use forests. The SEA recommended that the state government integrate its program for strengthening family agriculture with land-use planning criteria, based on cooperative systems The methodology employed has evidences to be replicable in other regions of Brazil and in developing countries.