基于改进蝴蝶算法和社会力模型的多出口疏散模型研究*

为提高多出口场景下行人疏散效率和精度,基于蝴蝶算法和社会力模型,提出一种新的应急疏散仿真路径规划方法。在原有社会力模型中,考虑距离出口远近及行人所处位置拥挤度对运动过程中期望速度的影响,引入速度调节因子,描述行人在疏散中的期望速度变化;针对蝴蝶算法中后期收敛速度慢和易陷入局部最优的缺陷,提出自适应感知概率参数以增强局部搜索和全局搜索之间的平衡;在每轮迭代结束时引入迭代局部搜索策略,扰动局部最优解获得中间状态,并重新搜索上述中间状态得到全局最优解。研究结果表明:提出的应急疏散仿真路径规划方法在多出口环境下能够更有效地利用出口资源,提高疏散效率。     

Managing climate change vulnerabilities: formal institutions and knowledge use as determinants of adaptive capacity at the local level in Sweden

Though managing vulnerabilities posed by climate change calls for effective strategies and measures, its challenges have hitherto not been fully understood. In Sweden, municipalities have recently started incorporating vulnerability management into their political and administrative agendas. This study discusses such experiences and explores how institutional determinants may influence adaptive capacity within a local case study area, to illustrate emerging challenges and opportunities for Swedish municipalities in managing climate vulnerabilities. Specifically, formal institutional structure and the use of knowledge are analysed, concluding that vulnerability management often is focused on technical and reactive fixes, due to limited co-operation between local sector organisations, lack of local co-ordination, and an absence of methods and traditions to build institutional knowledge. Even so, opportunities, such as a high capacity to examine risks to technical systems and important establishments which in turn facilitates protection of technical infrastructure exposed to climate variability and change, also exist.     

Policy support for rural economic development based on Holling’s ecological concept of panarchy

Globally, rural regions are searching for innovative growth opportunities to reinvigorate their economies. This paper examines the redevelopment of rural communities through an ecological lens – based on the notion of continuous cycles of adaptive change within complex systems as first identified within Holling’s concept of panarchy. Panarchy suggests that complex systems have more than a single equilibrium point and, instead, have some inherent resiliency based on the notion of multiple stable regimes. As such, panarchy provides a conceptual model that describes the ways in which complex social and ecological systems are organized and structured both spatially and temporally. By drawing parallels between the characteristics of ecological communities and rural economic systems, a novel framework is developed to assist policy-makers reflect on a rural community’s position along its own adaptive change cycle and, then, implement appropriate inventions to improve system resiliency – which in this case is linked with economic resiliency through development and/or growth. Supported by empirical data emerging from both key informant interviews and content analysis of current rural development policy, this work also identifies leverage points where policy intervention may be most advantageous by specifying the timing of policy instruments on the cycle. Specifically, this framework describes four leverage points, three major and one minor, to help push or pull rural regions into an area of higher resilience.     

Incorporating governance influences into social-ecological system models: a case study involving biodiversity conservation

Addressing environmental problems requires sophisticated approaches to complexity and uncertainty. Conceptual models are increasingly used to improve understanding of complex system interactions. However, cursory treatment of governance limits their analytical potential. This study included governance considerations in a social-ecological system model of biodiversity conservation in the Tasmanian Midlands (Australia). Effectiveness of engagement processes and conservation programme longevity were identified as critical governance influences. The conceptual representation of this system enabled exploration of how governance influences interact with social drivers (e.g. landholder engagement in conservation practices) to modify the effect of biophysical drivers (e.g. land use) on biodiversity outcomes. Such a methodology provides essential information for identifying and guiding governance related points of intervention.     

Incorporating geodiversity into conservation decisions

In a rapidly changing climate, conservation practitioners could better use geodiversity in a broad range of conservation decisions. We explored selected avenues through which this integration might improve decision making and organized them within the adaptive management cycle of assessment, planning, implementation, and monitoring. Geodiversity is seldom referenced in predominant environmental law and policy. With most natural resource agencies mandated to conserve certain categories of species, agency personnel are challenged to find ways to practically implement new directives aimed at coping with climate change while retaining their species‐centered mandate. Ecoregions and ecological classifications provide clear mechanisms to consider geodiversity in plans or decisions, the inclusion of which will help foster the resilience of conservation to climate change. Methods for biodiversity assessment, such as gap analysis, climate change vulnerability analysis, and ecological process modeling, can readily accommodate inclusion of a geophysical component. We adapted others’ approaches for characterizing landscapes along a continuum of climate change vulnerability for the biota they support from resistant, to resilient, to susceptible, and to sensitive and then summarized options for integrating geodiversity into planning in each landscape type. In landscapes that are relatively resistant to climate change, options exist to fully represent geodiversity while ensuring that dynamic ecological processes can change over time. In more susceptible landscapes, strategies aiming to maintain or restore ecosystem resilience and connectivity are paramount. Implementing actions on the ground requires understanding of geophysical constraints on species and an increasingly nimble approach to establishing management and restoration goals. Because decisions that are implemented today will be revisited and amended into the future, increasingly sophisticated forms of monitoring and adaptation will be required to ensure that conservation efforts fully consider the value of geodiversity for supporting biodiversity in the face of a changing climate.     

Missing the trees for the forest? Bottom-up policy implementation and adaptive management in the US natural resource bureaucracy

For decades, natural resource agencies in the United States have attempted to restore ecosystems using adaptive management, a process that emphasizes experimental learning to reduce uncertainty. Most studies show that it rarely occurs in practice and explain implementation failures as organizational issues. This study draws on policy implementation theory to suggest that behaviors and attitudes of individuals may better explain implementation gaps. This comparative case study finds differences between experts implementing adaptive management in the Fish and Wildlife Service and the United States Geological Survey. These include differences in attitudes, perceptions, and behaviors aimed at promoting individual autonomy, performance standards, and defending individual interests on the job. Policy implications are twofold: first, that individual behaviors impact adaptive management implementation and intrinsic motivation to perform such functions. Second, regardless of agency, experts view their work as a social good. This suggests that a devolved planning process may remedy implementation obstacles.     

Successes and Challenges from Formation to Implementation of Eleven Broad‐Extent Conservation Programs

Integration of conservation partnerships across geographic, biological, and administrative boundaries is increasingly relevant because drivers of change, such as climate shifts, transcend these boundaries. We explored successes and challenges of established conservation programs that span multiple watersheds and consider both social and ecological concerns. We asked representatives from a diverse set of 11 broad‐extent conservation partnerships in 29 countries 17 questions that pertained to launching and maintaining partnerships for broad‐extent conservation, specifying ultimate management objectives, and implementation and learning. Partnerships invested more funds in implementing conservation actions than any other aspect of conservation, and a program's context (geographic extent, United States vs. other countries, developed vs. developing nation) appeared to substantially affect program approach. Despite early successes of these organizations and benefits of broad‐extent conservation, specific challenges related to uncertainties in scaling up information and to coordination in the face of diverse partner governance structures, conflicting objectives, and vast uncertainties regarding future system dynamics hindered long‐term success, as demonstrated by the focal organizations. Engaging stakeholders, developing conservation measures, and implementing adaptive management were dominant challenges. To inform future research on broad‐extent conservation, we considered several challenges when we developed detailed questions, such as what qualities of broad‐extent partnerships ensure they complement, integrate, and strengthen, rather than replace, local conservation efforts and which adaptive management processes yield actionable conservation strategies that account explicitly for dynamics and uncertainties regarding multiscale governance, environmental conditions, and knowledge of the system? Éxitos y Retos de la Formación a la Implementación de Once Programas de Conservación de Amplio Alcance     

Managing water through change and uncertainty: comparing lessons from the adaptive co-management literature to recent policy developments in England

Water management is set to become increasingly variable and unpredictable, in particular because of climate change. This paper investigates the extent to which water policy in England provides an enabling environment for ‘adaptive co-management’, which its proponents claim can achieve the dual objective of ecosystem protection and livelihood sustainability under conditions of change and uncertainty. Five policy categories are derived from a literature review, and are used to conduct a directed content analysis of seven key water policy documents. The findings reveal that although, in part, English water policy serves as an enabling environment for adaptive co-management, there is a level of discrepancy between substantive aspects of the five policy categories and water policy in England. Addressing these discrepancies will be important if English water policy is to allow for the emergence of processes, like adaptive co-management, that are capable of coping with the challenges that lie ahead.     

Adaptive capacity and climate change: the role of community opinion leaders

The contribution of the informal community sector to the development of collective response strategies to socioecological change is not well researched. In this article, we examine the role of community opinion leaders in developing and mobilising stocks of adaptive capacity. In so doing, we reveal a largely unexplored mechanism for building on latent social capital and associated networks that have the potential to transcend local-scale efforts – an enduring question in climate change adaptation and other cross-scalar sustainability issues. Participants drawn from diverse spheres of community activity in the Sunshine Coast, Australia, were interviewed about their strategies for influencing their community objectives and the degree to which they have engaged with responding to climate change. The results show community opinion leaders to be politically engaged through rich bridging connections with other community organisations, and vertically with policy-makers at local, state, national and international levels. Despite this latent potential, the majority of community opinion leaders interviewed were not strategically engaged with responding to climate change. This finding suggests that more work is needed to connect networks knowledgeable about projected climate change impacts with local networks of community opinion leaders. Attention to the type of community-based strategies considered effective and appropriate by community opinion leaders and their organisations also suggests avenues for policy-makers to facilitate community engagement in responding to climate change across sectors likely to be affected by its impacts. Opportunities to extend understanding of adaptive capacity within the community sector through further research are also suggested.     

供应链食品安全管理自适应系统的结构设计

食品供应链是食品安全监管体系的重要组成部分和载体。本文探讨了自适应系统理论在供应链食品质量安全管理方面应用的可能性;针对目前的食品安全问题,依照自适应原理,设计了食品安全的自适应系统,该系统含有两套自适应的子系统,即低成本常规食品安全管理系统和高成本食品安全突发事件控制预测系统;两套子系统所采用的规则集不同,但可相互通讯,共享跟踪系统及其所采集的数据。整个系统最终输出的是安全供应渠道,与供应链决策系统中的成本、需求方向、生产计划等一起构成决定食品原材料供应来源的因素。系统以人工神经网络为自适应系统的主体,判断安全的食品供应结点并预测突发性食品安全问题;同时,提出了实现上述功能的一种可能的系统结构,以期有效实现食品安全的动态反应和控制,为完善我国食品质量安全管理提供新的思路。