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1.
《Environment international》1999,25(6-7):899-905
This study focuses on replicated exploratory optimizations of a large and difficult beef herd dynamics model, using the net present value over a 10-year planning horizon as the variable of interest. Faced with a practical search-space of the order of 10100 possible management decision combinations, the thorough but slow search pattern of simulated annealing struggled, on average falling 1.2% short of the global optimum of the system. By comparison, the cross-breeding and mutating nature of the genetic algorithm searches usually produced good results, averaging 0.1% from the global optimum. Also, these were achieved with about half the computing time used by the simulated annealing optimizations. Hence, for this problem, genetic algorithms proved the superior method.  相似文献   

2.
传粉作为重要的生态系统服务之一,对维持野生植物群落和粮食生产至关重要。近年来随着全球农业投入迅速增加,耕地利用集约化程度大幅提高,昆虫传粉能力受到严重影响。由于全世界约2/3的主要粮食作物依赖传粉服务,因此传粉服务的下降将威胁着全球粮食安全。然而,传粉服务与耕地利用集约水平的相互关系有待在全球各地区进行进一步验证,尤其在中国这种农业大国。以鄱阳湖滨湖区典型村落为研究对象,基于高精度土地利用数据、传粉蜜蜂生物物理数据、区域社会经济以及实地调研数据,采用InVEST模型、GIS分析工具、数理统计和回归分析方法。定量揭示小尺度上耕地集约利用与蜜蜂传粉服务之间的权衡关系。结果显示:(1)研究村落2000年和2013年蜜蜂传粉服务丰度平均值分别为0. 127和0. 108,期间下降幅度为15. 50%。总体上,研究村落蜜蜂传粉服务有较明显的削弱。(2)受退耕还林、退田还湖以及耕地撂荒等因素的综合影响,研究村落耕地利用区域减少了37. 66 hm~2,约占村落土地总面积的13. 55%。但由于农药、化肥、机械以及劳动力等投入的增加,该村各耕地利用类型的集约度分值均有大幅度提高,增幅均高达2倍以上。(3)耕地利用集约度变化与蜜蜂传粉服务变化回归系数为-0. 164,两者呈负相关关系,也即两者之间存在此消彼长的权衡关系。研究村落耕地利用集约度的提高削弱了蜜蜂传粉服务功能。  相似文献   

3.
由于规划项目涉及面广、不确定性强、行业多样等特点,目前还没有针对规划环评的通用方法。虽然很多适用于建设项目环境影响评价的方法可以直接用于规划环评,但二者之间仍存在着很大的不同。结合规划项目的环境影响评价特点与评价要求,参考国内现有行业标准规范与新发布的大气评价导则技术要求,提出了规划项目大气环境影响评价的基本工作流程和4个工作要点,并通过具体案例应用,分别从基础资料收集与分析、环境影响预测方案制定、规划方案的比选及环境承载力的测算给出具体说明与实施方法。通过预测评价分析及方案比选,对规划选址、发展规模、规划布局、产业结构以及区域规划发展方式等进行综合分析,最终针对规划项目的污染控制及规划方案提出调整建议,为今后规划环境影响评价工作提供依据和技术参考。  相似文献   

4.

Land abandonment is an important process for the European Union, which primarily occurs in less productive, remote and mountainous areas with unfavourable conditions for agriculture. Future management directions of these abandonment areas are under debate, with increasing calls to adjust policies to the local characteristics, including the promotion of rewilding and the management of succession of larger areas of less-productive land. While there is an increase in studies focusing on the environmental impacts of land abandonment, there are few studies that focus on the perceptions of abandonment by different user groups, even though an understanding of local perceptions, opportunities and trade-offs associated with changing land management is crucial for landscape-related policies and planning measures. In a case study in Northern Portugal, we used a combination of statements, photograph rating exercises and open questions to assess the perceptions of local inhabitants, visitors and experts regarding land abandonment and their preferences of different possible trajectories after abandonment. The results show that all user groups have a negative response towards abandonment and associate it mainly with negative emotions and the loss of heritage and traditions. The assessment of the different abandonment stages and outcomes clearly yielded different preferences and explanations, which can be used as input for finding a common ground for landscape management, reducing conflict and as a starting point for a more spatially targeted and nuanced management approach.

  相似文献   

5.
International aid is increasingly focused on adaptation to climate change. At recent meetings of the parties to the United Nations Framework Convention on Climate Change, the developed world agreed to rapidly increase international assistance to help the developing world respond to the impacts of climate change. In this paper, we examine the decision-making challenges facing internationally supported climate change adaptation projects, using the example of efforts to implement coastal protection measures (e.g. sea walls, mangrove planting) in Kiribati. The central equatorial Pacific country is home to the Kiribati Adaptation Project, the first national-level climate change adaptation project supported by the World Bank. Drawing on interview and document research conducted over an 8-year period, we trace the forces influencing decisions about coastal protection measures, starting from the variability and uncertainty in climate change projections, through the trade-offs between different measures, to the social, political, and economic context in which decisions are finally made. We then discuss how sub-optimal adaptation measures may be implemented despite years of planning, consultation, and technical studies. This qualitative analysis of the real-world process of climate change adaptation reveals that embracing a culturally appropriate and short-term (~20 years) planning horizon, while not ignoring the longer-term future, may reduce the influence of scientific uncertainty on decisions and provide opportunities to learn from mistakes, reassess the science, and adjust suboptimal investments. The limiting element in this approach to adaptation is likely to be the availability of consistent, long-term financing.  相似文献   

6.
Alpine areas in northwestern Yunnan, China possess globally significant levels of biodiversity and are important locally for livelihood activities such as livestock grazing and medicinal plant collection. Because local land use has important impacts on alpine conditions and communities have significant capacity to manage alpine resources, we emphasized local collaboration during the initial stages of conservation planning. Our collaboration with local communities investigated how livelihood strategies affect the condition of alpine resources in northwestern Yunnan and how future conservation efforts can be compatible with local livelihoods. We sampled three livestock herding sites, each within a different alpine sub-region, using open-ended interviews and maximum variation sampling. According to interviewees, livestock grazing within the alpine zone currently does not appear to be negatively impacting the availability of forage. Medicinal plant collection, however, is showing unsustainable trends. Tourism is as yet a nascent industry, but is seen as having great potential by those interviewed. It is clear that with increases in population, access to regional markets, and tourism, northwestern Yunnan’s rich alpine resources will require careful management. In addition to the data collected, we found that the methodology used may be widely applicable to organizations with limited resources that wish to engage local communities during the formative stages of regional-level conservation planning.  相似文献   

7.
中国反复、多次出现大范围持续性雾霾天气使碳排放与经济增长问题成为理论界研究的热点,选取1978~2012年中国历年相关统计数据,采用Gregory-Hansen协整检验方法结合结构突变分析,实证检验我国碳排放与能源消费、经济增长及产业结构的关系。研究结果显示,中国碳排放环境库兹涅茨曲线为正U型,且该曲线存在结构突变;经济增长、能源消费、产业结构对碳排放都具有显著的增排效应。因此,建议在保证经济可持续的中高速增长前提下,通过提高能源利用效率、推进产业结构调整等措施来降低碳排放量,使"APEC蓝"能够成为一种"新常态"。  相似文献   

8.
While methodological choices are critical for solution-oriented adaptation research, the current debate on these is underdeveloped and characterized by simple dichotomies such as bottom-up and top-down as well as vaguely defined concepts such as vulnerability. Adaptation challenges and approaches for addressing them are more diverse than these labels suggest. This paper addresses this deficit by developing a diagnostic framework that helps to identify approaches suitable for addressing a given adaptation challenge. The framework was developed out of the necessity to discuss diverse approaches from natural science, social science and practice in a set of adaptation case studies conducted within the European funded MEDIATION project. Based on these case studies complemented by the literature, we iteratively abstracted typical adaptation challenges researched, typical approaches taken, and empirical, theoretical and normative criteria applied for choosing a particular approach. Our results refine the methodological debate by distinguishing between the three general adaptation challenges of identifying adaptation needs, identifying adaptation measures and appraising adaptation options. Adaptation challenges are further classified according to private and public interest involved, individual or various types of collective action involved, data/model availability, decision-making time horizon, etc. For each type of challenge and approach, we give examples and discuss salient issues. Our results point to the opportunity to apply institutional and behavioural research to support the identification of measures and possibly avoiding barriers in practice. The diagnostic framework also serves as the basis for the forthcoming guidance for assessing vulnerability, impacts and adaptation to be published by the UNEP programme of research on climate change vulnerability, impacts and adaptation.  相似文献   

9.
Legitimacy of urban climate change adaptation: a case in Helsinki   总被引:1,自引:0,他引:1  
While there is general agreement on the necessity for local adaptation, there is a wide range of different understandings of what type of adaptation is seen as legitimate. It is often contested who should actively steer and take part in local adaptation, for which reasons and based on what kind of mandate, and with which methods. Planning theory can serve as a helpful reference point for examining the sources of legitimacy for adaptation in an urban context. From a planning perspective, adaptation is concerned with climate change as one out of many issues planning has to respond to. The layered co-existence of planning paradigms in practice suggests diverse, sometimes contradictory sources of legitimacy for urban planning and—as we claim here—also for climate change adaptation. This study examines the legitimacy of adaptation from a planning theoretical perspective in Helsinki, drawing on semi-structured interviews and social network analysis to show how adaptation is commonly understood from a rationalist perspective as an apolitical activity with local authorities’ experts designing and implementing adaptation. Nevertheless, some of the central actors understand adaptation as a communicative activity and a common deliberation of solutions. The co-occurrence of disparate paradigms results in ambiguous legitimacy that can impede the successful implementation of local climate change adaptation.  相似文献   

10.
In general, the issue of climate change is characterized by uncertainty, complexity, and multifacetedness. In the Netherlands, climate change is in above highly controversial. These characteristics make it difficult to realize adaptation measures that are perceived as legitimate. In this article, we analyze the main difficulties and dilemmas with regard to the issue of legitimacy in the context of climate adaptation. We conceptualize legitimacy from a legal, a planning, and a network perspective and show how the concept of legitimacy evolves within these three perspectives. From a legal perspective, the focus is on the issues of good governance. From a planning perspective, the focus is on the flexibility, learning, and governance capacity. From a network perspective, issues of dialogue, involvement, and support are important. These perspectives bring in different criteria, which are not easy compatible. We describe and illustrate these legitimacy challenges using an in-depth study of the Dutch IJsseldelta Zuid case. From our case study, we conclude that, from a legitimacy perspective, the often acclaimed necessity to be adaptive and flexible is quite problematic. The same holds true for the plea to mainstream adaptation into other policy domains. In our case study, these strategies give rise to serious challenges in relation to good governance and consensus—two indispensable cornerstones of legitimacy.  相似文献   

11.
快速工业化区域是工业化快速发展、工业化水平迅速提升、经济社会结构急剧变化的新兴地域类型。普遍存在着建设用地总量急剧扩张、空间无序分散、城乡缺乏统筹等问题。本文从佛山市南海区典型案例入手,运用新制度经济学原理。归纳和解析了快速工业化区域城乡建设用地的主要问题,认为双二元管理体制、农村土地产权不完善、城乡土地市场发育不平衡和部门规划不协调等是建设用地发展的主要体制性障碍因素,并从管理、产权、市场、规划等方面系统提出相应的制度优化对策。  相似文献   

12.
In this paper we examine how Canadian and Flemish municipalities manage and measure sustainable development initiatives. First, we present information on how Canada, Belgium and its Flemish region introduce sustainable development initiatives at the federal and regional levels of government. The introduction at municipal level of impact assessment systems, indicator and monitoring systems, and sustainability reporting systems is discussed in general, followed by a comparison of specific case studies. In Canada, we selected the municipalities of Ottawa, Hamilton-Wentworth and Vancouver and in Flanders, the municipalities of Hasselt, Gent and Leuven. For each case study, we considered the following evaluation criteria: introduction of a long-term vision for a sustainable future; development of goals, targets and indicators; measurement of indicators; involvement and information of the local population; introduction of impact assessment and reporting systems. The discussion section deals with differences in the approach to managing and measuring sustainable development initiatives in Canada and Flanders. This study shows that sustainable development is not yet widely practised at the local level in Canada and Flanders, but Canadian municipalities have more experience with planning processes and vision development, measurement systems and public involvement. The Flemish municipalities were more inclined to go along with international campaigns dealing with local sustainability and take strong sustainable development actions which were not integrated in broader sustainable development policies.  相似文献   

13.
标准地域单元划分是国土空间规划关于国土空间综合分区进行空间评价的基础。为了给国土空间规划编制提供更好的单元服务,在借鉴欧盟NUTS划分思路的基础上,提出了建立符合中国国情的省级国土空间规划基本评价单元模式——国土空间标准地域划分(NUTSP)理念,构建了标准地域单元划分的原则、依据和技术路线,并结合湖南省对省级尺度国土空间标准地域划分的具体实施途径进行了探讨。研究结果表明,根据NUTSP划分原则与方法,结合湖南省域内不同地域的地形地貌特征、资源禀赋差异、社会经济发展基础等因素,并与综合自然地理区划相衔接,对全省现有122个县级行政区划单元进行适当合并与拆分,重新划定135个国土空间标准地域单元,能从最大限度上满足未来全省国土空间规划对空间同质性与异质性的表达需求,对未来建立统一的空间规划体系和探索"多规合一"工作具有重要意义。  相似文献   

14.
Abstract

In recent years, the concepts of sustainability and product service system have been closely associated with each other. In today’s competitive markets, due to Extended Producer Responsibility and customer environmental awareness, producers shift from ‘product-seller’ towards ‘product-service provider’ for using the environmental and economic advantages of coupling a product with services. This paper proposes a novel approach to determine the optimal warranty period and the out-of-warranty replacement period, from the point of view of the producer and the customer to minimise the total cost of usage and end of life of product. As regards the fact that adopted strategies by producers and customers sometimes are in conflict and it affects choosing the optimal product usage period, a game theory model was developed in this study. Finally, a case study with data from chain of local notebook service centres was applied to demonstrate some practical aspects of the developed model.  相似文献   

15.
生态单元制图是通过对区域遥感信息的解译及与现场调查信息的叠合,得到可视性较强的生态信息图谱,是将景观生态学成果应用到城乡规划中的一条有效途径。生态单元制图如何与中国城乡规划编制相衔接,提供专业、可靠的基础性研究成果,是本文期待解决的主要问题。提出了将城市所有用地类型都作为研究对象的"本土化"和"城市化"的生态单元分类方法,完成了符合我国《城市用地分类与建设用地标准》的生态单元制图分类系统(9大类37小类)及其景观生态学指数分析;通过绿地率、建筑密度、乔木树冠覆盖度、植物物种丰富度等各单项指标进行分层及叠加综合评价制图,科学全面地识别不同用地的生态价值。认为可以通过提出诸如各类城市用地的附属绿地的面积、容积率高低、建筑退让范围、大乔木的保护措施等具体细致的规划要求,来保护及调整城市用地内部的绿地面积及植被丰富度、乔木的覆盖度等生态指标,确保重要的城镇自然系统在城市开发过程中不受冲击,以及如何实现我国城市绿地的"精明增长"等后续研究方向。  相似文献   

16.
Throughout Asia, rapid and uncontrolled urbanization has created serious environmental problems, and the development of sustainable urban–rural planning methods is of critical importance. To improve our understanding of mixed urban–rural land uses and provide future practical visions for regional planning, we conducted a case study of the urban fringe of the Bangkok Metropolitan Region, Thailand. After identifying local irrigation districts as the basic spatial unit for resource circulation, we quantified current material flows of organic wastes generated by households within each district. We then developed two different land-use scenarios for 2020: (1) a high-rise compact and (2) a low-story sprawl development scenario. These scenarios were compared in terms of efficiency of material flows and energy consumption. We found that, based on current infrastructure and technology, the latter scenario was more advantageous in terms of both material input and energy consumption than the former, thereby, identifying positive aspects of urban–rural land-use mixture. Based on these results, we propose that planners should focus on density control measures that take into account bioresource circulation within irrigation districts rather than simply drawing arbitrary land-use zoning lines. To this end, we suggest that the division between agricultural and urban planning departments must be bridged, and that research should take an interdisciplinary approach.  相似文献   

17.
上海都市旅游业与现代服务业互动机制研究   总被引:2,自引:0,他引:2  
以现代服务业与都市旅游业的相关性做为切入点,以上海为例,结合都市旅游的产品体系,分析了都市旅游业对现代服务业的动力作用,运用迈克尔.波特的“钻石体系”理论和相关产业族群理论,分析了现代服务业对都市旅游业的支援作用,提出了旅游业与现代服务业从产业融合到空间融合作用机理,然后从建立现代服务业集聚区、培育现代服务集团、培养复合型服务人才、加快现代服务业的支持政策等方面提出发挥旅游业与现代服务业互动作用的具体措施与思路。  相似文献   

18.
The methodology of material flow analysis is presented and applied to developing a phosphorus balance in a river basin and evaluating different scenarios for pollution reduction. The method is based on the balance principle: inputs and outputs of each phosphorus-related subsystems were balanced. The application of the methodology strategies was illustrated by means of a case study of the Krka River, Slovenia. The results showed that besides effluents from wastewater treatment plants, agriculture contributed significantly to the total annual phosphorus load. After establishing the present levels of phosphorus balance, different scenarios were considered: different stages of wastewater treatment as well as management of agricultural activities. The present emission of phosphorus is estimated to be 81.8 tons/year; after implementation of measures, it would be 48.6 tons/year, a total reduction of 40%. Besides reduction of point sources by means of wastewater collection and implementation of nutrient removal technology, managing agricultural phosphorus to protect water quality should become a major challenge in the Krka river basin.  相似文献   

19.
GIS支持下土壤侵蚀潜在危险度的分级研究   总被引:21,自引:0,他引:21  
根据土壤侵蚀特点,在IDRISI地理信息系统(GIS)支持下,研究设计了小流域空间与属性数据库的建设,在GIS系统支持下可有效地实现区域土壤侵蚀潜在危险的分级及其空间分析。首先,采用侵蚀预报的数学模型来估算土壤侵蚀星,用土壤详查资料编制土层厚度和土壤容重图,然后,由土壤年均侵蚀量,土层厚度和土壤容重得到土壤抗蚀年限图,按水利部标准将土壤侵蚀潜在危险度分为5级。最后,为表明某一地区或地类土壤侵蚀潜在危险的大小,还提出了土壤侵蚀潜在危险指数(SEPDI)。以三峡库区的王家桥小流域为例进行了研究,并且分析了其空间分布特点。  相似文献   

20.
Biodiversity conservation is critical for the continued supply of ecosystem services to secure the sustainability of livelihoods, especially for poor rural people in developing countries. Current rates of biodiversity loss need to be curbed by using effective interventions and decision-making that again require timely information. Undertaking a community sustainability assessment to generate and structure this information for grassroots levels is critical for decision-making and actions. This paper presents insights from a community sustainability assessment initiative undertaken in Lesotho within a trans-boundary project area known as the Maloti-Drakensberg Transfrontier Project. A qualitative case study approach was employed through a combination of several data collection techniques, including a literature review, field observations, key informant interviews, group discussions and key informant workshops. Study participants consisted of members of the community conservation forums from three districts that had been established by the project. Regarding progress towards the sustainability of biodiversity in the study area, the results indicated that current practices are unsustainable, more from the point of view of the socio-ecological components than the socio-cultural and spiritual or the socio-economic components. Consequently, there is a need to raise awareness at the community level and implement action plans to realize changes that support the sustainability of biodiversity in the long term.  相似文献   

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