Keywords

1 Introduction

Cities as socio-ecological systems are facing the growing challenges posed by a broad array of stressors such as climate change, population growth, urbanization, natural and man-made disasters, and resource depletion. Recognition of the fact that not all these threats can be avoided has led to the diffusion of the concept of resilience (Renschler et al. 2010a). The increasing attention to resilience is reflected in the growing number of assessment tools and frameworks developed to measure resilience of urban communities and various activities and projects undertaken to operationalize assessment strategies. Resilience assessment tools are either focused on single sectors or take a multi-sectoral approach. Those falling under the latter category have a broad approach toward resilience and try to address different environmental, social, economic, and institutional aspects of urban resilience.

As resilience assessment is a relatively new and still growing field, there is a paucity of studies elaborating on different indicators that should be incorporated into urban resilience assessment tools. Indicators should be used to transform resilience into a measureable concept and provide a lens through which complexities of cities as socio-ecological systems can be better understood. These indicators can later be used to develop assessment tools that, among other things, can be used to determine baseline conditions, evaluate effectiveness of interventions, and measure progress in achieving community goals. These functions signify the important role of resilience indicators as building blocks of any assessment system. An appropriate assessment tool should feature characteristics such as multi-dimensionality and comprehensives, context-specificity, simplicity, replicability, updatability, and scalability (Cutter et al. 2010). This chapter tries to elaborate on the multi-dimensionality and comprehensiveness characteristic of urban resilience assessment indicators. For this purpose, the theoretical underpinnings of urban resilience and various resiliency principles are described in the next section. In Sect. 3 various indicators, which are drawn from an extensive review of literature on urban resilience assessment, are grouped under five major themes. Section 4 proposes development of resilience matrices that can better explain to which stages of the disaster risk management process each indicator relates. In addition, these matrices can provide information on resilience characteristics associated with each indicator. If developed, such matrices can help planners and decision makers make more informed decisions when prioritizing resource allocation for enhancing resilience of urban communities.

2 Underlying Characteristics of Urban Resilience

Resilience is a contested and normative concept. This could be explained by the fact that it has been adopted by various disciplines that have interpreted it differently according to their needs and priorities. It was originally developed in physics and psychology. Over the past four decades it has been introduced to other fields such as ecology, engineering, and disaster risk management. Although introduction of resilience notion to urban studies occurred comparatively late, it has been rapidly gaining ground since the turn of the century (Sharifi and Yamagata 2014, 2016). Engineering resilience, ecological resilience, and socio-ecological resilience are three major approaches that can be found in the literature. The first approach conceptualizes resilience of a system as its physical resistance and its capacity to rapidly return to an equilibrium state in case the thresholds are exceeded (Sharifi and Yamagata 2016). The ecological approach to resilience acknowledges that shocks are not always predictable. It advocates enhancing the tolerance of the system and recognizes that the system may need to shift to new equilibrium state(s) in order to be able to retain its pre-disaster functionality (Sharifi and Yamagata 2016). The adaptive approach to resilience is based on the conceptualization of (urban) system as a dynamic socio-ecological entity that continuously undergoes transformation. Accordingly the system may not necessarily return to an equilibrium state after the disruptive event. System integrity, self-organization capacity, and learning are three main components that contribute to adaptive resilience of a system and enable it to not only bounce back from disruptions, but also bounce forward to a more desired state (Sharifi and Yamagata 2016).

The fact that cities are socio-ecological systems, that feature dynamic interactions across time and space, implies that the adaptive approach to resilience can provide a more suitable theoretical basis for conceptualizing urban resilience (Sharifi and Yamagata 2016). This approach is reflected in The National Academies’ definition of resilience as “the ability to prepare and plan for, absorb, recover from and more successfully adapt to adverse events” (TNA 2012, P14) which is adopted for the purpose of this chapter. To achieve, maintain, and strengthen these abilities, any urban system should entail the following characteristics: robustness, stability, flexibility, resourcefulness, coordination capacity, redundancy, diversity, foresight capacity, independence, connectivity and interdependence, collaboration capacity, agility, adaptability, self-organization, creativity and innovation, efficiency, and equity (Sharifi and Yamagata 2016). These criteria are distilled from the literature and only briefly explained here. These broad characteristics form the basis for development of a matrix approach that will be discussed later on in this chapter. A more detailed explanation can be found in Sharifi and Yamagata (2014, 2016). Robustness and stability refer to the system’s strength against short-term and long-term shocks, respectively. Flexibility indicates the ability to rearrange structure and functions when facing disruptions. Resourcefulness relates to availability of resources needed for enhancing the above-mentioned four abilities of a resilience system. Coordination capacity is needed to make optimal use for resources at disposal of citizens, planners, and decision makers. Redundancy is important to ensure that, in case components of the system are out of function, they can be substituted by spare components that have been included for this purpose. Diversity refers to inclusion of different components in the system that can be used simultaneously and can make up for each other’s dysfunction. Foresight capacity is directly related to the uncertainties innate in the urban system and preparatory work that needs to be done to address potential disruptions. Independence gives the system a certain degree of self-reliance that may be needed to survive adversities. Connectivity refers to interactions and relations that need to be established with other systems that exist in a broader scale. This is particularly important for shock absorption and timely recovery. Collaboration highlights the need for an inclusive and bottom-up approach towards urban management. Agility is related to how fast an urban system can restore its functionality following a disruptive event. Adaptability is specifically related to the capacity to learn and to integrate the notion of “living with risk” in planning and everyday life practices. Self-organization includes establishing and strengthening community-based and voluntary activities centered on social institutions and networks. Creativity is required to find innovative solutions for addressing emergent and unprecedented problems. Efficiency entails considering costs and benefits of actions and developing strategies for maximizing benefits given the limited resources available. Last, but not the least, equity is important to ensure fair distribution of benefits and impacts across different groups in the society (Sharifi and Yamagata 2014, 2016).

When thinking about these characteristics it should not be forgotten that synergies and tradeoffs exist between some of them. For instance improving redundancy may have adverse implications for efficiency of the system. Or, a balance point between independence and connectivity may differ from one context to another and, generally, finding balance between these two may turn out to be very challenging (Sharifi and Yamagata 2016). In order to develop a comprehensive and informative assessment system, it is needed to further discuss these synergies and tradeoffs and also clarify how each of the characteristics is related to planning/preparation, absorption, recovery, and adaptation as the four major abilities integrated into resilient urban systems. Addressing the former is beyond the scope of this chapter. The latter will be briefly discussed in Sect. 4 when proposing a matrix approach to facilitate a transparent and informed assessment framework that can identify whether resilience characteristics have been reflected in the urban system.

3 Multiple Dimensions of Urban Resilience

Resilience is a multi-faceted aspect and, ideally, all different dimensions of an urban system should be addressed in a resilience assessment framework. This section provides a list of various criteria that can be used for developing a resilience assessment system. Although context specificity issues should be taken into account when developing assessment frameworks, paying attention to all relevant criteria is needed for enhancing integrity and content validity of the assessment system. A detailed content analysis of 29 resilience assessment frameworks was conducted to distill major dimensions and criteria related to resilience of urban systems.

A complete list of these assessment frameworks can be found in Table 1. The extracted criteria have been divided into five categories (each referring to a specific dimension) according to their similarities. These are materials and environmental resources, society and well-being, economy, built environment and infrastructure, and governance and institution. Each of these dimensions will be further discussed in the following sections.

Table 1 The analyzed resilience assessment frameworks [adapted from the draft version of Sharifi (2016). Thirty six tools have been analyzed in the published version]
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3.1 Materials and Environmental Resources

Criteria mentioned in Table 2 are mainly related to quality, availability, accessibility, and conservation of resources. Through providing ecosystem services, environmental resources play a significant role in enhancing resilience of communities. Some resources such as wetlands are necessary for absorbing impacts of disasters such as flood and improving recovery process. Availability and accessibility to clean and affordable resources is essential for survival and prosperity of human communities. Therefore, appropriate measures in terms of resource protection and management should be taken for achieving resilient communities.

Table 2 Criteria related to materials and environmental resources [adapted from Sharifi (2016)]
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3.2 Society and Well-Being

Criteria related to this dimension can be found in Table 3. This dimension has received considerable attention in the urban resilience literature and is believed to have a strong influence on the achievement of community self-sufficiency and resilience. This signifies the recognition of the fact that physical and engineering measures alone will not be sufficient for creating resilient communities.

Table 3 Criteria related to society and well-being [adapted from Sharifi (2016)]
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Criteria grouped under socio-economic characteristics can be used to measure community’s status in terms of capacity and diversity of human resources. The second group of criteria are related to social capital. Both structural criteria such as existence of civic organizations and cognitive ones such as norms of reciprocity and trust should be taken into account (Sherrieb et al. 2010). Both trust between citizens and trust in official information sources are important. Place attachment and strong sense of community are indicators of commitment to the future of the community and enhance chances of building networks and establishing relationships with other community members (Chelleri et al. 2015). As mentioned earlier, however, the issue of tradeoffs should not be undermined. For instance although place attachment enhances recovery process, strong attachment to place may result in lack of willingness to move to safer places. This will exacerbate the suffering from losses and accordingly it can be said that place attachment can in some cases “impair, rather than facilitate” resilience (Norris et al. 2008). Safety and well-being criteria improve stability of communities. Safe and healthy communities are more capable of withstanding and responding to shocks (Chandra et al. 2011). Equity and diversity are important because impacts of disasters are often experienced unevenly in communities, with vulnerable groups suffering the most. Enhancing equity will be an effort to tackle this problem. Finally, respecting local cultures and traditions is an important element of the learning process which, among other things, can improve the adaptation aspects of resilience.

3.3 Economy

The economic dimension of urban resilience includes criteria related to the structure of the economy, its security and stability, and its dynamism (Table 4). Economic resilience of a community depends on the capacity and skillfulness of its working population to support the dependent population. Availability of reasonably-paid jobs can also be associated with resilience (Burton 2014).

Table 4 Criteria related to economy [adapted from Sharifi (2016)]
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Appropriate planning is needed to reduce potential business interruptions. For this purpose, availability of business mitigation plan will be essential. Such a plan should include financial instruments and insurance plans to ensure economic security of the community. Community members should be aware of the importance of community savings for enhancing redundancy and resourcefulness and also recognize the importance of collective resource ownership for maintaining access to resources for which severe competition exists (Schwind 2009).

Inward investment and economic diversity are indicators of community’s ability to attract and retain businesses and avoid negative impacts of economic decline (NIST 2015a). Communities reliant on a single industry are expected to be more vulnerable to disruptions. Both large and small businesses are needed to ensure inward investment and business continuity.

There is evidence suggesting that, compared to large chain stores, local small businesses are more effective in keeping the money circulating within the local economy. This also provides other co-benefits such as additional tax revenues and strong networks wherein local businesses collaborate and employ local workers (Schwind 2009). Large businesses should also exist since evidence suggests that they tend to be better capable of coping with change and recovering from disruptions (Sherrieb et al. 2010). Integration with the regional economy and collaboration agreements are also important for better absorption of shocks and for facilitating a timely recovery process. Also, public-private partnership is needed to adequately prepare individual businesses and also encourage them to engage in collective actions (CARRI 2013).

3.4 Built Environment and Infrastructure

Criteria related to the built environment and infrastructure are listed in Table 5.

Table 5 Criteria related to the built environment and infrastructure [adapted from Sharifi (2016)]
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Infrastructure has often a long lifetime. Therefore, careful attention is needed to avoid the risk of lock-in into vulnerable and inefficient urban infrastructure. Redundancy facilitates substitutability of infrastructure in case some parts stop functioning. Robustness implies enhancing resistance of infrastructure and fortifying them against shocks. This may, however, result in complacency and a false perception of safety in the community. Multi-functionality of urban spaces and facilities improves diversity and efficiency characteristics which are essential for shock absorption and timely recovery. For instance, while parks and green spaces are mainly used for purposes such as recreation, thermal comfort provision, and air pollution mitigation, they can provide additional benefits in terms of evacuation and flood mitigation. Similarly, sport arenas and educational facilities can be used for temporary sheltering when needed.

In order to enhance infrastructure efficiency, regular monitoring is needed to inform planners and citizens of the need for actions such as retrofit, refurbishment, and technology update.

Of the various types of infrastructure, more emphasis has been put on communication and transportation systems. Good communication and information sharing are regarded as fundamental for enhancing resilience (Norris et al. 2008). The main role of transportation infrastructure systems is in survivor evacuation, and rescue and aid operations (Faturechi and Miller-Hooks 2015).

Criteria related to land use and urban design have major implications for resource security and management in cities. They can also provide resilience against threats such as urban flooding and extreme heat events. It must be kept in mind that the optimum state with respect to some of these criteria may vary depending on the context and type of disruption. For instance while higher levels of density increase energy resilience of cities, there is evidence showing that lower density is better for resilience against floods and hurricanes (Burton 2014).

3.5 Governance and Institutions

Governance is a cross-cutting dimension that has various inter-relationships with the other dimensions explained above. Governance and institutional criteria are shown in Table 6 and can be used to evaluate the efficiency and effectiveness of relationships between and within community organizations and entities.

Table 6 Criteria related to governance and institutions [adapted from Sharifi (2016)]
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Governance and institutional rules define how different activities are communicated and what mechanisms exist to make contingency and mitigation plans and ensure that they are implemented. Strong leadership enhances resilience by strengthening linkages between various elements of the system and empowering bonding and bridging social networks (Frankenberger et al. 2013).

Also, bottom up citizen involvement and transparent decision making is needed to enhance legitimacy of actions and make sure that they have a high level of buy in from the local community. Decentralized and bottom-up initiatives reduce hierarchical complexities. This provides a platform for civic collaborations, encourages community mobilization, and facilitates exchange of ideas and experiences leading to better preparation and response to disasters (Renschler et al. 2010b). A shared vision should be established and guide all the planning activities in the community. This is argued to be essential for enhancing resilience (Norris et al. 2008).

Due to the complexity of various stressors such as climate change, it would be unlikely that communities be capable of addressing various problems independently. Therefore, collaboration, learning, and information exchange should be necessary components of any resilience planning efforts. Organizational connectivity and presence of interconnected networks is argued to be important for enhancing resilience (Norris et al. 2008). Establishing an integrated network of organizations and individuals can also be effective in increasing trust and knowledge exchange among the members and improve their willingness to partake in mitigation and preparation, and recovery plans (Chandra et al. 2011).

4 Proposed Resilience Matrices

In Sect. 2 resilience was defined as “the ability to prepare and plan for, absorb, recover from and more successfully adapt to adverse events” (TNA 2012, P14). It was also discussed that any resilient system should entail different characteristics, namely robustness, stability, flexibility, resourcefulness, coordination capacity, redundancy, diversity, foresight capacity, independence, connectivity and interdependence, collaboration capacity, agility, adaptability, self-organization, creativity and innovation, efficiency, and equity. The main purpose of any resilience assessment framework should be the achievement of better-informed decisions. Following the “Resilience Matrix” approach proposed by Fox-Lent et al. (2015), here, it is argued that creating matrices that specify to which ability each characteristic may relate could further aware planners and decision makers of the importance of each ability and characteristic. The proposed matrix would have a structure as shown in Table 7.

Table 7 Proposed matrix to indicate the relationship between resilience abilities and characteristics
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It would also be useful to develop other matrices based on abilities, characteristics, and criteria mentioned in this chapter. First, a set of matrices that identify to which ability each criterion mentioned in Tables 2, 3, 4, 5 and 6 is related. Second, a set of matrices that show which characteristics are influenced as a result of inclusion of the resilience criteria in the planning process. The relationships can be indicated by checking the respective cells in the matrix. However, as some of the relationships (or influences) may be characterized as either positive or negative, it is preferable to also display the direction of the relationships. As demonstrated in Fox-Lent et al. (2015), it can also be possible to use qualitative and/or quantitative indicators to calculate estimated scores for performance of each cell [e.g. score in terms of planning/preparation for “ecosystem monitoring and protection” (M1)]. This matrix approach can be used for prioritization of activities and resource allocation and lends itself to better planning towards urban resilience. The proposed structure for these matrices is shown in Tables 8 and 9. Here only the proposed matrices for criteria related to materials and environmental resources are shown. Similar matrices should be developed for criteria related to the other four dimensions of urban resilience.

Table 8 Proposed matrix structure to explore association between resilience abilities and urban resilience criteria
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Table 9 Proposed matrix structure to explore association between resilience characteristics and urban resilience criteria
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5 Conclusions

Resilience thinking is rapidly gaining ground in science and policy circles. Among other benefits, developing resilience assessment frameworks can be regarded as useful for reducing the complexities of urban resilience and clarifying the inter-relationships between various aspects of resilience. To this end, it is necessary to understand different characteristics of resilience systems and also identify various dimensions of resilience. In addition to identifying major resilience characteristics, this study introduced five major dimensions of urban resilience and an extensive list of criteria related to them. Subsequently a matrix approach was proposed that can be used to further explore the relationship between these criteria and characteristics. Also, it was suggested that additional work is needed to investigate how the four defining abilities of resilience are related to resilience characteristics and criteria. What discussed in this chapter provides a conceptual framework for developing resilience assessment tools. This should be regarded as a preliminary work that needs to be further developed in the future. The next step should be focused on methodologies to complete the matrices proposed in Sect. 4. The matrices could be completed by either using stakeholder/expert opinions, or by taking evidence-based approaches such as literature review and/or analysis of actual behavior of urban systems in response to disasters. Although some components of the matrices could be regarded as generic, some others may be context specific and the final output is likely to vary from one context to another. Resilience assessment will also require identifying specific indicators related to each criterion. This will also be a highly context-specific task. Due to context-specificity issues, it is likely that not all criteria mentioned in this chapter will be useful for application in all contexts.

Another essential task required for building comprehensive and informative resilience assessment tools would be explaining synergies and tradeoffs that may exist between the different components of the system. This would be necessary for achieving better-informed decision making.