Many scholars use the adaptive cycle to illustrate resilience (Gunderson and Holling, 2002, Walker and Salt, 2006, Walker et al., 2004, Folke, 2006). Understood as the capacity to deal with risks and respond positively, the adaptive cycle focuses on the dynamics of systems (e.g., ecosystems, societies, and economies) which do not have a stable or equilibrium condition but repeatedly pass through four characteristic phases: growth and exploitation; conservation; collapse or release; and renewal and reorganisation. These shifts between phases are the result of either sequences of gradual changes (such as exploitation, conservation, and reorganisation) or rapid shocks (such as collapse). Endogenous disturbances are not just considered as threats but also as opportunities to enhance the overall health and self-organisation of the system (Gunderson and Holling, 2002, Walker and Salt, 2006, Walker et al., 2004).
For example, a wetland ecosystem may collapse during an environment catastrophe.
After disasters, some of the species in the system may return it to its original balance by shifting to a new stable state and becoming more robust.
Under the concept of the adaptive cycle, the notion of resilience can be expressed in terms of a system’s robustness or strength (i.e., the ability to remain functional in an extreme shock) and rapidity or flexibility of response (i.e., the ability to bounce back).
Figuur 3 presents an illustration. The curve shows the trajectory of a system through the four stages. Line A illustrates a possible response through growth, conservation, collapse or release, and renewal and reorganisation. Line B shows a more resilient system which does not drop so far in performance. The difference between Lines A and B is robustness. Line C drops as far but recovers quickly. This shows the different speeds of recovery. Line D indicates a system that drops less, recovers more quickly and achieves higher performance as outcome result. The increased performance that results may represent learning in the system, either the evolution of a natural system or changes in policy.
Line A
or release Renewal and reorganisation Future state Time
Figuur 3
Relationship between resilience, robustness and rapidity through four phases of the adaptive cycle (Source: based on Linnenluecke and Grif fiths, 2010)
For example, in a flood-prone area, a city’s resilience can be illustrated in terms of preparations before the occurrence of flooding and actions after the disturbances occur. Preparations made before the occurrence of floods can be the selection of building types in vulnerable areas, flood-control systems and administration of flood risk management. These represent an increase of robustness. Actions that result from the disturbances can be the development of city drainage systems, rapid response units, damage repairs, rescue services, financial support and future improvements. This may affect the speed at which a system may recover, or its rapidity. The new condition of a city may not necessarily be the same as its state before a disturbance occurred.
The capacity of robustness and rapidity are two crucial items represented in decision-making for the improvement of the resilience of a city. However, policy-makers may also overlook the multidisciplinary and complex nature of the notion and use the term with a limited understanding (Jabareen, 2013). Focusing on a single or small number of contributing factors to urban resilience can easily lead to the exclusion of important characteristics that affect the performance of a city. For example, strategies for flood risk management may only take into consideration improving the performance from line A to B by creating water retention ponds to minimise the disturbances in the neighbourhoods. This only increases the capacity of robustness. Strategies may also only be concerned with creating more capacity that shifts the performance from line A to C by adding pumping facilities in the neighbourhoods. This considers only the rapidity, the speed of return. Both strategies dismiss the possibility to increase the performance from line A to D.
Another difficulty in applying resilience in planning is related to the various understandings of the notion that result from the different focuses, interests and training backgrounds of decision-makers (Stumpp, 2013). Policy-makers may interpret the notion narrowly according to their background or interchange the term with other terminologies that are more familiar in their fields. This also causes a difficulty in increasing the performance of the urban systems from line A to D that represents a new paradigm to planning practices.
In spite of the obstacles in relation to the understanding of resilience, the notion has been increasingly adopted in policy-making. The notion of resilience has not been confined just to academic discourses – it is also increasingly prevalent in urban policy documents (O’Hare and White, 2013). This can be seen particularly in the context of facing the issues of climate change. The discussion of resilience and climate change is presented in the next section.
§ 3.3 Promoting urban resilience in facing climate-related flood risks
Climate change is an increasingly important issue for spatial planning (Campbell, 2006, Wilson and Piper, 2010, O’Hare and White, 2013, Coaffee, 2013, Davoudi et al., 2013). According to Wardekker et al. (2010), the impact of climate change is not only associated with disruptive events, such as storms or heat waves, but also with gradual trends (e.g. rises in sea level or increasing CO2 emission that will rise average global temperatures) that can still give rise to large disturbances if left unchecked. The notion of resilience is becoming increasingly important for policy-makers facing climate change and its environmental impacts. In spite of lacking clear definitions to put into practice, the notion of urban resilience is increasingly addressed in planning studies related to the impact of climate disturbances in cities. For example, Newman et al.
(2009) argued that if a city is able to reduce its oil dependence it has a higher chance or remaining stable than cities that highly depend on fossil fuels.
One of the advantages of using this concept is to highlight the interactions between science and policy-making (McEvoy et al., 2013). This is based on a realisation that climate change requires new forms of engagement and collaboration between scientists, policy-makers and wider stakeholder communities. Single actors or professions can hardly manage the consequences of the complexity of climate change. A number of recent studies (e.g., Wilson and Piper, 2010, White, 2010, Davoudi, 2012, 2013, IPCC, 2007) indicated a fact that spatial planning can play an important role in promoting resilience in the face of climate change. Spatial planning can integrate different concepts sequentially and implement these ideas into local practices by organising land use change
or by requiring certain forms of urban development. Therefore, spatial planning provides a means of both adapting to the adverse impacts of climate disturbances and mitigating emissions that influence climate change. These discussions are increasingly prevalent in urban policy documents around the world, especially in places where decision-makers are keen to develop local-level adaptive strategies (Wilson, 2006).
Folke et al. (2004) acknowledged the efficacy of studying resilience in helping planners to understand, manage and govern the uncertainty between people and nature caused by the occurrences of disturbances. From this perspective, resilience can be considered as an advanced understanding of urban sustainability that focuses more on appropriate resource management and not much at all on managing unforeseen threats and unstable situations. Studies of resilience in facing risks associated to the impact of climate change often concentrate on uncertain situations that are more difficult to prepare in advance. Because of this, scientific projects are important for providing scenarios of future conditions that can be taken into consideration of policy-making to initiate strategies for urban development. For example, studies of rising sea level can help to define the areas where may become more vulnerable to floods in the future. Based on the information, decision-makers can regulate future development in places where are less influenced by potential floods, to strengthen flood protection in places where are critical to the cities, and to develop new typologies of spatial development that can adapt and remain sustaining in higher water periods.
As presented in section 3.2, a system’s robustness (or strength) and rapidity (or flexibility) of response are both important to promote a resilient city in tackling uncertain situations. The issue of robustness is closely related to mitigation activities that strengthen the capacity of a city to remain functional in disturbances, and rapacity is primarily linked to adaptation activities that minimise the disturbances and recover the cities efficiently. For example, a city can sustain flooding disturbances by having mitigation facilities (e.g., storm surge barriers and dikes) and adaptive strategies (e.g., adaptive plans and new building topologies) that help the city remain functional during the high water level period.
Increasing resilience requires that most mitigation activities and many adaptation activities. Although both adaptation and mitigation efforts are important in dealing with the impacts of climate change, they are not necessarily integrated or complementary due to the traditional division, different actors of policy-making and the operation at different levels of government (Tol, 2005). High-density mixed-use settlements (compact cities) provide an example. Although urban consolidation can reduce energy demand and transport emission, it can also be in conflict with the adaptation approach. It may intensify the urban heat island effect and put pressure on urban drainage, or can have an indirect negative effect on the environment by things such as the increasing use of air-conditioning which cause additional emissions of greenhouse gases (Howard, 2009).
Policy-making for mitigation or adaptation often depends on the scale of planning:
mitigation is often addressed at higher scales, and adaptation is considered at the local level (Howard, 2009). For example, coastal settlements need to strengthen sea defences and drainage facilities to cope with rising sea level and extreme rainfall caused by climate change, but these generally require more than action at the local or community level alone.