A new flood risk assessment framework for evaluating the effectiveness of policies to improve urban flood resilience

To better understand the impacts of flooding such that authorities can plan for adapting measures to cope with future scenarios, we have developed a modified Drivers-Pressures-State-Impact-Response (DPSIR) framework to allow policy makers to evaluate strategies for improving flood resilience in cities. We showed that this framework proved an effective approach to assessing and improving urban flood resilience, albeit with some limitations. This framework has difficulties in capturing all the important relationships in cities, especially with regards to feedbacks. There is therefore a need to develop improved techniques for understanding components and their relationships. While this research showed that risk assessment is possible even at the mega-city scale, new techniques will support advances in this field. Finally, a chain of models engenders uncertainties. However, the resilience approach promoted in this research, is an effective manner to work with uncertainty by providing the capacity to cope and respond to multiple scenarios.     

城市绿色基础设施 韧性设计范式转型探索

Urban green infrastructure is a fundamental physical structure that supports the construction of resilient cities based on nature. Currently, the conventional design paradigm oriented by deterministic control is not conducive to promoting urban resilience, and the design paradigm of green infrastructure is in urgent need of transformation. Based on literature review, this article discusses the establishment of resilient design paradigm: first, it proposes the common ground of the resilient design paradigm by establishing a framework for the resilience mechanism of urban green infrastructure; then it summarizes the resilience driving mechanism to provide the key basis for the resilience design paradigm; and finally, this article devises the resilient design paradigm based on adaptive approaches and proposes the whole-process dynamic cyclic model to guide the configuration optimization of urban green infrastructure. The establishment of the design paradigm relies on the shift in mindset, concept, design procedure, project management, quality inspection, etc., which requires the joint efforts by designers, engineers, researchers, decision makers, and the public. This article is expected to provide references not only to the construction of green infrastructure to support the high-performance of urban resilience, but also to the theory development of resilient city and the resilient design paradigm of landscape design.     

高密度沿海地区洪涝风险评价与适应性规划策略 ——以深圳湾地区为例

气候变化背景下，高密度沿海城市受 到风暴潮和极端降雨引起的洪涝灾害冲击。文 章基于韧性理论构建城市空间洪涝风险指标 体系，制定该评价框架的实施路径；基于水文 软件Mike21、GIS平台及其空间网络分析插件 sDNA，复合“天鸽”台风风暴潮与极端降雨情 景，整合深圳湾地区的路网和土地利用进行危 险性、暴露度、脆弱性和适应能力等多源数据； 通过GIS栅格计算得到各要素层分析及洪涝风 险评价可视化地图，结果显示，潮、洪、涝突破 刚性标准加剧了危险性，高密度城市环境增大了 危险区域的暴露度，路网和土地利用布局具有 一定脆弱性，需完善应急疏散和避难场所规划以增强适应能力；根据评价地图识别高风险片区，从路网和土地利用等城市空间物质要素出发， 提出应对洪涝灾害的适应性规划策略。     

城市抗震韧性评估研究进展

现阶段，我国大城市与城市群内人员和社会财富高度密集，基础设施林立，城市地震安全问题严重威胁着我国新型城镇化战略的实施，灾害脆弱性已经成为现阶段城镇化进程中制约城市可持续发展的核心问题，实现工程设施、城市乃至整个社会的抗震韧性已经成为国际地震工程界的共识。抗震韧性城市的研究涉及地震学、土木工程、人工智能、遥感技术、社会学、经济学、管理学等多个学科，是一项极具挑战性的课题。文中阐明了城市抗震韧性的定义，系统总结了城市抗震韧性评估的国内外研究现状，并提出了建设抗震韧性城市所涉及到的科学技术问题及韧性能力提升策略。     

气候变化下的三角洲城市韧性规划研究

三角洲城市是一个特殊、复杂的生态-人工系统。水系冲击形成的地形地貌条件、大量建设产生的地基沉降现象以及城市蔓延造成的生境破坏,使得三角洲城市更容易受到由气候变化带来的潮汐、风暴潮以及暴雨的侵蚀。本文首先分析了三角洲城市更具脆弱性的原因,即特殊的自然基底与快速城市化的矛盾是产生三角洲城市脆弱性的内在原因,气候变化是加剧三角洲城市脆弱性的外在因素,认为韧性发展是未来三角洲城市发展优先考虑的对策。其次,讨论了韧性城市所具有的特征、模型、评估指标、多尺度生命周期、韧性演进等问题,重点从韧性城市的视角研究了曾经遭受气候灾害的若干三角洲城市的规划理念,推演了三角洲城市韧性发展的逻辑框架。第三,提出了三角洲城市韧性发展的目标,即通过规划调控协同三角洲城市系统各要素,持续推进整体应对气候变化扰动的能力。第四,提出了三角洲城市韧性规划调控的核心思想是多元与多样的基础设施、冗余与跨尺度的网络联系、自组织与自我更新的区域/街区/建筑/景观格局。最后,提出了六个在韧性规划实践中值得进一步研究的问题。     

RESILIENT URBAN DESIGN METHODS AND PRINCIPLES BASED ON THE COMPLEX ADAPTIVE SYSTEM THEORY

Uncertainty exists in the current urban development of contemporary cities and is getting diversified and complicated. Identifying and adapting to such uncertainty is partly defining the future development of urban planning and design. The concept of “resilient city” is developed from the current scientific demands in urban planning and design. This article suggests that Complex Adaptive System as a new system theory would help resilient city planning and construction. According to the Complex Adaptive System theory, a resilient city should possess the adaptability of its components, diversity, autonomy, appropriate redundancy, slow-variable management, and identification, in order to improve the ecological, social, and economic resilience and vitality of the city.     

Making the implicit,explicit: time for renegotiating the urban water supply hydrosocial contract?

Today's modern cities' ‘big-pipes in, big-pipes out’ potable water supply approach does not offer society the resilience for adaptation to future climate challenges. One approach towards building resilience would involve cities adopting diverse, alternative water supplies; such as recycled wastewater, greywater and stormwater, within a fit-for-purpose philosophy, incorporating a mix of centralised and decentralised technologies. Globally, modern cities have limited on-ground experience with such complex approaches, despite ad-hoc policy rhetoric to the contrary and multiple technological options. Through considering the implicit and technocratic hydrosocial contract underpinning the current ‘big pipes’ approach, it appears the judgement and advice of ‘water experts’ is a significant determinant regarding opportunities for realising more resilient water supplies. Contrasting primary and secondary survey data from water experts and communities across Australian cities in relation to their receptivity to alternative water supplies; it is evident that community members are far more receptive than water experts expect. Thus, this difference in perception is potentially a significant barrier to realising a resilient approach. Path-dependant decision-making and practice is pervasive throughout the urban water field, and while the physical artefact of the traditional water supply system remains largely invisible and disconnected from communities, it is the implicit hydrosocial contract that keeps water experts disconnected from communities. Based on evidence presented in this paper, shifting the current hydrosocial contract to a more resilient approach is vulnerable to business as usual. Recommendations are offered for fundamentally reshaping this contract through deliberative processes that work towards enabling co-governance, co-design and co-management of this alternative and complex water supply approach into the future.     

Resilient cities: meaning, models, and metaphor for integrating the ecological, socio-economic, and planning realms

Urban designers, ecologists, and social scientists have called for closer links among their disciplines. We examine a promising new tool for promoting this linkage—the metaphor of “cities of resilience.” To put this tool to best use, we indicate how metaphor fits with other conceptual tools in science. We then present the two opposing definitions of resilience from ecology, and give reasons why one is more appropriate for linking with design. Additional specific tools and insights that are emerging from, or being increasingly used in, ecology can further support the linkage with urban design. These include recognizing the role of spatial heterogeneity in both ecological and social functioning of urban areas, the integrating power of watersheds, social and ecological patch dynamics of cities, the utility of spatial mosaic models to capture function, the use of an integrated “human ecosystem” modeling framework, and the consequent perspective of metropolitan areas as integrated ecological-social systems. Three additional tools are related to the adaptability of people and human institutions. First is the recognition of a “learning loop” in metropolitan ecosystems in which people respond to and affect ecological change, the use of urban design as experiments whose ecological and social outcomes can be measured, and finally the potency of a dialog between professionals and citizens, communities, and institutions, to support both research and design. The metaphor of resilience, and its technical specifications, draw these diverse strands for linking ecology and planning together.     

Alternative Resilience Indices for City Ecosystems Subjected to Natural Hazards

Prompt and efficient responses against natural hazards are needed to build cities capable of withstanding disasters, namely resilient cities. This study aims at presenting and testing synthetic resilience indices over a real urban center threatened by multiple hazards, for which a global overview of city performance is requested. An integrated framework is proposed for quantitative resilience assessment by way of time‐independent synthetic indices. The approach proposed is in accordance to the complex network theory and uses a global indicator of the system connectivity to assess the city functioning also in case of network disruption. Resilience is evaluated as a proxy for systemic urban damage by modeling a city ecosystem as a hybrid social–physical network. Seismic and landslide scenario analyses are performed for the city of Sarno, Italy. A probability‐based approach is used to compute urban vulnerability. Subsequently, to highlight changes in results according to the type of disaster, a recovery strategy is simulated to assess efficiency and damage states in each recovery stage, and urban resilience.     

RESILIENCE AND MIMETIC BEHAVIOR: ECONOMIC VISIONS IN THE GREAT RECESSION

The Great Recession was a moment of challenge for many regions and required that leaders reflect on their economic development strategies. Given the propensity of regions to adopt ideas and strategy “fads” that then inform policy debate, we seek to understand how two very different regions with different histories framed their responses to the recession. How did they conceptualize the economic challenge in their region? What did they envision as appropriate responses to this challenge? How did these visions relate to mimetic behavior of the past, in which largely uniform visions are adopted across diverse locations? Our findings show that economic development leaders in the Buffalo and Orlando regions advocated similar high‐tech/biomedical strategies as a way to diversify their economies and make them more resilient or less vulnerable to future shocks. By conceptualizing economic diversification in such similar ways, despite substantial regional differences, this pursuit of resilience or decreased vulnerabilities through economic diversification appears highly similar to prior mimetic behaviors. We consider the implications of this finding for theories of adaptive resilience in which the focus is on economic diversification as part of resilient processes and behaviors, rather than as a fixed characteristic or end state of regions. As practiced in our case studies, diversification for the purpose of resilient outcomes differs substantially from theoretical arguments explaining adaptive resilience as both behavior and process. We caution that policy and planning visions of resilience may therefore represent yet another fad to be mimicked ad infinitum. Nevertheless, adaptive resilience as defined in the literature may still offer promise as a practical strategy—just not one that we yet observe in practice.     

Development of a stochastic framework to design/rehabilitate urban stormwater drainage systems based on a resilient approach

Urban floods may cause a wide range of undesirable consequences in populated areas when drainage networks do not have enough capacity or encounter unexpected loads such as blockage. Although both external loads (like heavy rainfalls) and internal factors such as structural failure/blockage of different parts of networks play an important role on urban inundation, most of the implemented design approaches only consider effects of external loads on Urban Stormwater Drainage Systems (USDSs). In this study, a new resilient and stochastic approach is developed by connecting a multi objective optimization algorithm to a numerical solver/meta-model within a Copula-based Monte-Carlo framework in order to design/rehabilitate of USDSs considering the related probabilities of external and internal unexpected conditions of loading. Results indicate the importance of considering the resilience in the rehabilitation of Tehran Stormwater Drainage System (TSDS), Tehran, Iran. Optimal strategies including a set of bypass lines, relief tunnels, and storage units, exhibited satisfactory performance in terms of enhancing the network resiliency.     

平疫结合的城市韧性社区建设与规划应对

作为疫情防控的基础单元,城市社区在面对突发公共卫生事件的冲击时,良好的应对能力对减少病毒传播、降低灾害损失至关重要。文章通过解读平疫结合的韧性社区内涵,从物质空间和社会空间层面构建了韧性社区评估框架,结合基层社区在新型冠状病毒肺炎疫情中的表现,剖析社区在疫情防控中存在的问题,并针对不足提出规划应对策略。期望为未来城市社区的韧性提升提供有益参考。     

A framework for the future of urban underground engineering

A special and holistic approach is needed that captures aggregate attributes and emergent behaviors of the complex system of infrastructure systems in a region. Effective management of the impacts of future population growth, urbanization, and risks arising from continued evolution of our natural, physical and human/societal systems will require a systematic exploration and characterization of the urban subsurface, including much improved understanding and assessment of geologic risks. With recent cost escalations for underground construction projects, incentives are needed for the underground construction industry to develop and implement innovations in methods and technology, and smart integrated planning is needed to reduce costs both during construction and with life-cycle engineered design and operation of our subsurface facilities.The needed framework requires investigation of potential metrics that reflect the performance of aggregate functions of an urban environment so that we can holistically study system performance response under “normal” and “stressed” operation. Such a metric can support a cross-disciplinary exploration of urban resilience, and build knowledge as we develop and test theory and models that explore resilience of complex socio-technical systems. Econometrics with spatial and temporal granularity will help to understand the integrated functionality of our cities and to establish appropriate policies that will drive continuous improvement in the quality of urban life while providing natural, human, and physical urban environmental resilience. The underground in urban regions can become an important component of managing the increasing complexity of our physical systems, and can also make more significant contributions to improving the robustness and resilience of our future cities.     

应对突发公共事件的社区建设策略--基于“社区”概念的辨析

2020年春节前后的新型冠状病毒肺炎疫情是新中国成立以来在我国发生的传播速度最快、感染范围最广、防控难度最大的一次重大突发公共卫生事件,不仅影响了国内外千万人的健康乃至生命,还凸显出城市特别是社区尺度在应对公共危机过程中存在的不足。文章以建构韧性社区为目标,通过对"社区"概念内涵以及相应的社会实践特点的辨析,试图对当前城市韧性不足的成因进行解释,并以此为基础提出建设对策和建议。     

From sustainability to adaptation: Goldman Sachs’ corporate real estate strategy

This paper is premised on a conceptual framework that attempts to draw theoretical and practical connections between sustainability, resilience and adaptation. The framework is explored through a case study of the corporate real estate (property) strategies of Goldman Sachs (a multinational investment banking and investment management company) developed over the course of the consolidation and development of its corporate headquarters. This case seeks to identify the existence and nature of the relationships by and between sustainable corporate real estate strategies, resilient operations planning and the firm's adaptive capacity. A secondary proposition seeks to evaluate whether the capacity of the firm to adapt and be resilient to changing conditions has been positively advanced by the firm's sustainable corporate real estate strategies. The findings support the proposition that these connections do exist, as well as the proposition that sustainability was promoting adaptive capacity and operational resilience. However, it remains an open question to what extent these practices and capacities are deterministic of one another. This paper sets the stage for future research that seeks to measure and model organizational adaptive capacity and to understand the potential co-benefits that may serve the interests of firms who struggle to rationalize the costs of sustainability.     

A master plan for low carbon and resilient housing: The 35 ha area in Hashtgerd New Town, Iran

With 60% of the population younger than 26 years, a need of about 1.5 million residential units per year for the next 5 years and the necessity of mitigating its rapidly growing GHG emissions together with adapting cities to the expected drastic effects of climate change, Iran’s urban agglomerations are facing tremendous challenges now and in the future. The paper presents interim findings of the German–Iranian research initiative “Young Cities” (2005–2013) that investigates approaches for these immense challenges. The project aims at developing energy-efficient and resilient housing in a real-life pilot project, the 35 ha area in Hashtgerd New Town in the Tehran province. The article explores the framing conditions and the master plan of this pilot and identifies four key planning strategies. Besides applying climate-sensitive urban form, the project stresses the need to develop culturally adapted building typologies for reduced heating and cooling, an efficient public transport in a mixed and dense urban structure and integrated water and energy systems on the neighborhood level. Simulations of these planning approaches have proven a significant reduction of energy- and resource consumption and the capacity of the design to adapt to (a potentially changing) environment. These promising strategies for energy-efficiency and resilience were transferred into a legally binding comprehensive plan commissioned in October 2010, though the major challenge in the second phase of the project (2011–2013) will be making these innovations a built reality.     

DESIGN FOR RESILIENCE: RE-CONNECTING COMMUNITIES AND ENVIRONMENTS

This article stresses the importance of positive image and perception of dynamic ecological processes for the implementation and care of areas which provide ecosystem services within the city. Those in turn secure the resilience of our urban environment. Aesthetic experience with emphasis on highlighting and revealing the presence of ecological dynamics, processes and cycles can increase the acceptance and interest for sustainable goals and projects within the city. Thus, several European cities are currently implementing strategies not only to enhance the capacity of their green networks for ecological services and resilience but most importantly to enhance the acceptance and active use of such areas. They are integrating the public in an open debate about implementing new attractive ecological amenities within a green network, and also stimulating landscape architects to find ways to design important ecological processes and functions in an eye-catching and spectacular way. The natural dynamics and cycles are thus brought to the attention of the people and present an important artistic and cultural component of resilience.     

Urban flood impact assessment: A state-of-the-art review

Flooding can cause major disruptions in cities, and lead to significant impacts on people, the economy and on the environment. These impacts may be exacerbated by climate and socio-economic changes. Resilience thinking has become an important way for city planners and decision makers to manage flood risks.

Despite different definitions of resilience, a consistent theme is that flood resilient cities are impacted less by extreme flood events. Therefore, flood risk professionals and planners need to understand flood impacts to build flood resilient cities. This paper presents a state-of-the-art literature review on flood impact assessment in urban areas, detailing their application, and their limitations. It describes both techniques for dealing with individual categories of impacts, as well as methodologies for integrating them. The paper will also identify future avenues for progress in improving the techniques.     

The politics of resilient cities: whose resilience and whose city?

It is vital to acknowledge the socio-political complexity of the deployment of the term ‘resilience’ and to develop a more unified set of expectations for the professions and disciplines that use it. Applied to cities, resilience is particularly problematic, yet also retains promise. Like resilience, the term ‘city’ is also subject to multiple contending definitions, depending on the scale and on whether the focus is on physical spaces or social communities. Due to cities and city-regions being organized in ways that both produce and reflect underlying socio-economic disparities, some parts are much more resilient than others and therefore vulnerability is often linked to both topography and income. Uneven resilience threatens the ability of cities as a whole to function economically, socially and politically. Resilience can only remain useful as a concept and as progressive practice if it is explicitly associated with the need to improve the life prospects of disadvantaged groups. This dimension is often lost in definitions of resilience drawn from engineering and ecology, but remains central to conceptualizations linked to social psychology. To improve the prospects of cities proactively (and reactively), there is a need to unify the insights from the multiple professions and disciplines that use ‘resilience’.