Urban resilience has conventionally been defined as the "measurable ability of any urban system, with its inhabitants, to maintain continuity through all shocks and stresses, while positively adapting and transforming towards sustainability".[1]
Therefore, a resilient city is one that assesses, plans and acts to prepare for and respond to hazards, regardless whether they are natural or human-made, sudden or slow-onset, expected or unexpected. Resilient Cities are better positioned to protect and enhance people's lives, secure development gains, and drive positive change.[1]
History
According to the urban historian Roger W. Lotchin the 2nd World War had an profound environmental impact on urban areas in the USA. By 1945 Pittsburgh and other cities along the Mississippi River experienced air pollution comparable to the Dust Bowl. The environmental impact of the 2nd World War turned urban areas around the world into shock cities.[2] Extreme cases of hard hit cities include Hiroshima, Chongqing, Stalingrad, and Dresden.[3] Environmental history first emerged as an academic research topic in the 1970s, focusing initially on rural areas.[4] Pioneers of urban environmental history include Martin Melosi, Christine Rosen, Joel A. Tarr, Peter Brimblecombe, Bill Luckin, and Christopher Hamlin.[5] Recurrent climate changes have prompted renewed interest in this academic field.[6] The concern for urban resilience in the urban planning of cities has become increasingly visible in recent years, partly because urban resilience can be used to describe the change in structure and function of urban areas. Social scientists have taken an increased interest in ecological resilience, because the links between social-ecological systems are being examined. Urban resilience is no longer the preserve of academics, urban policy documents around the globe are putting forward proposals to enhance the urban resilience of cities. The definition of urban resilience may vary, but are no longer limited to the speed at which an urban systems recover after a shock.[7]
Accordingly, resilience strategies have tended to be conceived of in terms of counter-terrorism, other disasters (earthquakes, wildfires, tsunamis, coastal flooding, solar flares, etc.), and infrastructure adoption of sustainable energy. More recently, there has been an increasing attention to the evolution of urban resilience [10] and the capability of urban systems to adapt to changing conditions. This branch of resilience theory builds on a notion of cities as highly complex adaptive systems. The implication of this insight is to move urban planning away from conventional approaches based in geometric plans to an approach informed by network science that involves less interference in the functioning of cities. Network science provides a way of linking city size to the forms of networks that are likely to enable cities to function in different ways. It can further provide insights into the potential effectiveness of various urban policies.[11] This requires a better understanding of the types of practices and tools that contribute to building urban resilience. Genealogical approaches explore the evolution of these practices over time, including the values and power relations underpinning them.
Building resilience in cities relies on investment decisions that prioritize spending on activities that offer alternatives, which perform well in different scenarios. Such decisions need to take into account future risks and uncertainties. Because risk can never be fully eliminated, emergency and disaster planning is crucial.[12] Frameworks for disaster risk management, for example, offer practical opportunities for enhancing resilience.[13]
More than half of the world's human population has lived in cities since 2007, and urbanization is calculated to rise to 80% by 2050.[14] the growing urbanization over the past century has been associated with a considerable increase in urban sprawl. Resilience efforts address how individuals, communities and business not only cope on the face of multiple shocks and stresses, but also exploit opportunities for transformational development.
As one way of addressing disaster risk in urban areas, national and local governments, often supported by international funding agencies, engage in resettlement. This can be preventative, or occur after a disaster. While this reduces people's exposure to hazards, it can also lead to other problems, which can leave people more vulnerable or worse off than they were before. Resettlement needs to be understood as part of long-term sustainable development, not just as a means for disaster risk reduction.[15]
In September 2015, world leaders adopted the 17 Sustainable Development Goals (SDGs)[16] as part of the 2030 Agenda for Sustainable Development. The goals, which build on and replace the Millennium Development Goals,[17] officially came into force on 1 January 2016 and are expected to be achieved within the next 15 years. While the SDGs are not legally binding, governments are expected to take ownership and establish national frameworks for their achievement. Countries also have the primary responsibility for follow-up and review of progress based on quality, accessible and timely data collection. National reviews will feed into regional reviews, which in turn will inform a review at the global level.
UN-Habitat's City Resilience Profiling Tool (CRPT)
As the UN Agency for Human Settlements, UN-Habitat is working to support local governments and their stakeholders build urban resilience through the City Resilience Profiling Tool (CRPT). When applied, UN-Habitat's holistic approach to increasing resiliency results in local governments that are better able to ensure the wellbeing of citizens, protect development gains and maintain functionality in the face of hazards. The tool developed by UN-Habitat to support local governments achieve resilience is the City Resilience Profiling Tool. The Tool follows various stages and UN-Habitat supports cities to maximize the impact of CRPT implementation.
Getting started Local governments and UN-Habitat connect to evaluate the needs, opportunities and context of the city and evaluate the possibility of implementing the tool in their city. WIth our local government partners, we consider the stakeholders that need to be involved in implementation, including civil society organizations, national governments, the private sectors, among others.
Engagement By signing an agreement with a UN agency, the local government is better able to work with the necessary stakeholders to plan-out risk and built-in resilience across the city.
Diagnosis The CRPT provides a framework for cities to collect the right data about the city that enables them to evaluate their resilience and identify potential vulnerability in the urban system. Diagnosis through data covers all elements of the urban system, and considers all potential hazards and stakeholders.
Resilience Actions Understanding of the entire urban system fuels effective action. The main output of the CRPT is a unique Resilience Action Plan (RAP) for each engaged city. The RAP sets out short-, medium- and long-term strategies based on the diagnosis and actions are prioritised, assigned interdepartmentally, and integrated into existing government policies and plans. The process is iterative and once resilience actions have been implemented, local governments monitor impact through the tool, which recalibrates to identify next steps.
Taking it further Resilience actions require the buy-in of all stakeholders and, in many cases, additional funding. With a detailed diagnostic, local governments can leverage the support of national governments, donors and other international organizations to work towards sustainable urban development.
To date, this approach is currently being adapted in Barcelona (Spain), Asuncion (Paraguay), Maputo (Mozambique), Port Vila (Vanuatu), Bristol (United Kingdom), Lisbon (Portugal), Yakutsk (Russia), and Dakar (Senegal). The biennial publication, Trends in Urban Resilience, also produced by UN-Habitat is tracking the most recent efforts to build urban resilience as well as the actors behind these actions and a number of case studies.[18]
Medellin Collaboration for Urban Resilience
The Medellin Collaboration for Urban Resilience (MCUR) was launched at the 7th session of the World Urban Forum in Medellín, Colombia in 2014. As a pioneering partnerships platforms, it gathers the most prominent actors committed to building resilience globally, including UNISDR, The World Bank Group, Global Facility for Disaster Reduction and Recovery, Inter-American Development Bank, Rockefeller Foundation, 100 Resilient Cities, C40, ICLEI and Cities Alliance, and it is chaired by UN-Habitat.[19]
MCUR aims to jointly collaborate on strengthening the resilience of all cities and human settlements around the world by supporting local, regional and national governments. It addresses its activity by providing knowledge and research, facilitating access to local-level finance and raising global awareness on urban resilience through policy advocacy and adaptation diplomacy efforts. Its work is devoted to achieving the main international development agendas, as it works to achieve the mandates set out in the Sustainable Development Goals, the New Urban Agenda, the Paris Agreement on Climate Change and the Sendai Framework for Disaster Risk Reduction.
The Medellin Collaboration conceived a platform to help local governments and other municipal professionals understand the primary utility of the vast array of tools and diagnostics designed to assess, measure, monitor and improve city-level resilience. For example, some tools are intended as rapid assessments to establish a general understanding and baseline of a city's resilience and can be self-deployed, while others are intended as a means to identify and prioritise areas for investment. The Collaboration has produced a guidebook to illustrate how cities are responding to current and future challenges by thinking strategically about design, planning, and management for building resilience. Currently, it is working in a collaborative model in six pilot cities: Accra, Bogotá, Jakarta, Maputo, Mexico City and New York City.
100 Resilient Cities and the City Resilience Index (CRI)
The Rockefeller Foundation, rates 100 cities for resilience. The Rockefeller Foundation states that: "Urban Resilience is the capacity of individuals, communities, institutions, businesses, and systems within a city to survive, adapt, and grow no matter what kinds of chronic stresses and acute shocks they experience."
A central program contributing to the achievement of SDG 11 is the Rockefeller Foundation's 100 Resilient Cities. In December 2013, The Rockefeller Foundation launched the 100 Resilient Cities initiative, which is dedicated to promoting urban resilience, defined as "the capacity of individuals, communities, institutions, businesses, and systems within a city to survive, adapt, and grow no matter what kinds of chronic stresses and acute shocks they experience".[20]
The professional services firm Arup has helped the Rockefeller Foundation develop the City Resilience Index based on extensive stakeholder consultation across a range of cities globally. The index is intended to serve as a planning and decision-making tool to help guide urban investments toward results that facilitate sustainable urban growth and the well-being of citizens. The hope is that city officials will utilize the tool to identify areas of improvement, systemic weaknesses and opportunities for mitigating risk. Its generalizable format also allows cities to learn from each other.[21]
The index is a holistic articulation of urban resilience premised on the finding that there are 12 universal factors or drivers that contribute to city resilience. What varies is their relative importance. The factors are organized into the four core dimensions of the urban resilience framework:[22]
A total of 100 cities across six continents have signed up for the Rockefeller Center's urban resilience challenge. All 100 cities have developed individual City Resilience Strategies with technical support from a Chief Resilience Officer (CRO). The CRO ideally reports directly to the city's chief executive and helps coordinate all the resilience efforts in a single city.
A core factor enabling progress on all other dimensions of urban resilience is urban governance. Sustainable, resilient and inclusive cities are often the outcome of good governance that encompasses effective leadership, inclusive citizen participation and efficient financing among other things. To this end, public officials increasingly have access to public data, enabling evidence-based decision making. Open data is also increasingly transforming the way local governments share information with citizens, deliver services and monitor performance. It enables simultaneously increased public access to information and more direct citizen involvement in decision-making.[23]
Digital technologies
As part of their resilience strategies, city governments are increasingly relying on digital technology as part of a city's infrastructure and service delivery systems. On the one hand, reliance on technologies and electronic service delivery has made cities more vulnerable to Phone hacking and Cyber-attacks. At the same time, information technologies have often had a positive transformative impact by supporting innovation and promoting efficiencies in urban infrastructure, thus leading to lower-cost city services. The deployment of new technologies in the initial construction of infrastructure have in some cases even allowed urban economies to leapfrog stages of development.[23] An unintended outcome of the growing digitalization of cities is the emergence of a digital divide, which can exacerbate inequality between well-connected affluent neighborhoods and business districts, on the one hand, and under-serviced and under-connected low-income neighborhoods, on the other. In response, a number of cities have introduced digital inclusion programs to ensure that all citizens have the necessary tools to thrive in an increasingly digitalized world.
Climate change
Images of Salt Lake City, show positive correlation between white reflective roofs and cooler temperatures. Image A depicts an aerial view of Salt Lake City, Utah, site of 865000 sqft white reflective roof. Image B is a thermal infrared image of same area, showing hot (red and yellow) and cool (green and blue) spots. The reflective vinyl roof, not absorbing solar radiation, is shown in blue surrounded by other hot spots.
The urban impacts of climate change vary widely across geographical and developmental scales. A recent study [24] of 616 cities (home to 1.7 billion people, with a combined GDP of US$35 trillion, half of the world's total economic output), found that floods endanger more city residents than any other natural peril, followed by earthquakes and storms. Below is an attempt to define and discuss the challenges of heat waves, droughts and flooding. Resilience-boosting strategies will be introduced and outlined.
Heat waves and droughts
Heat waves are becoming increasingly prevalent as the global climate changes. The 1980 United States heat wave and drought killed 10,000 people. In 1988 a similar heat wave and drought killed 17,000 American citizens.[25] In August 2003 the UK saw record breaking summer temperatures with average temperatures persistently rising above 32°C. Nearly 3,000 deaths were contributed to the heat wave in the UK during this period, with an increase of 42% in London alone.[26] This heat wave claimed more than 40,000 lives across Europe.[27] Research indicates that by 2040 over 50% of summers will be warmer than 2003 and by 2100 those same summer temperatures will be considered cool.[28] The 2010 northern hemisphere summer heat wave was also disastrous, with nearly 5,000 deaths occurring in Moscow.[29] In addition to deaths, these heat waves also cause other significant problems. Extended periods of heat and droughts also cause widespread crop losses, spikes in electricity demand, forest fires, air pollution and reduced biodiversity in vital land and marine ecosystems.[30] Agricultural losses from heat and drought might not occur directly within the urban area, but it certainly affects the lives of urban dwellers. Crop supply shortages can lead to spikes in food prices, food scarcity, civic unrest and even starvation in extreme cases. In terms of the direct fatalities from these heat waves and droughts, they are statistically concentrated in urban areas,[31] and this is not just in line with increased population densities, but is due to social factors and the urban heat island effect.
Urban heat islands
Urban heat island (UHI) refers to the presence of an inner-city microclimate in which temperatures are comparatively higher than in the rural surroundings. Recent studies have shown that summer daytime temperatures can reach up to 10°C hotter in a city centre than in rural areas and between 5–6°C warmer at night.[32] The causes of UHI are no mystery, and are mostly based on simple energy balances and geometrics. The materials commonly found in urban areas (concrete and asphalt) absorb and store heat energy much more effectively than the surrounding natural environment. The black colouring of asphalt surfaces (roads, parking lots and highways) is able to absorb significantly more electromagnetic radiation, further encouraging the rapid and effective capture and storage of heat throughout the day. Geometrics come into play as well, as tall buildings provide large surfaces that both absorb and reflect sunlight and its heat energy onto other absorbent surfaces. These tall buildings also block the wind, which limits convective cooling. The sheer size of the buildings also blocks surface heat from naturally radiating back into the cool sky at night.[33] These factors, combined with the heat generated from vehicles, air conditioners and industry ensure that cities create, absorb and hold heat very effectively.
Social factors for heat vulnerability
The physical causes of heat waves and droughts and the exacerbation of the UHI effect are only part of the equation in terms of fatalities; social factors play a role as well. Statistically, senior citizens represent the majority of heat (and cold) related deaths within urban areas[34] and this is often due to social isolation. In rural areas, seniors are more likely to live with family or in care homes, whereas in cities they are often concentrated in subsidised apartment buildings and in many cases have little to no contact with the outside world.[35] Like other urban dwellers with little or no income, most urban seniors are unlikely to own an air conditioner. This combination of factors leads to thousands of tragic deaths every season, and incidences[spelling?] are increasing each year.[36]
Adapting for heat and drought resilience
Greening, reflecting and whitening urban spaces
An aerial view of Delhi, India where urban forests are being developed to improve the weather resistance and climate resilience of the cityPeople kayaking down a street in Mid-City New Orleans following flooding in 2019
Greening urban spaces is among the most frequently mentioned strategies to address heat effects. The idea is to increase the amount of natural cover within the city. This cover can be made up of grasses, bushes, trees, vines, water, rock gardens; any natural material. Covering as much surface as possible with green space will both reduce the total quantity of thermally absorbent artificial material, but the shading effect will reduce the amount of light and heat that reaches the concrete and asphalt that cannot be replaced by greenery.[37]
Trees are among the most effective greening tool within urban environments because of their coverage/footprint ratio. Trees require a very small physical area for planting, but when mature, they provide a much larger coverage area. This both absorbs solar energy for photosynthesis (improving air quality and mitigating global warming), reducing the amount of energy being trapped and held within artificial surfaces, but also casts much-needed shade on the city and its inhabitants. Shade itself does not lower the ambient air temperature, but it greatly reduces the perceived temperature and comfort of those seeking its refuge.[38]
An increasingly popular method of preventing the so called urban heat island (UHI) is the increasing of albedo (light reflectiveness). This can be done by using reflective paints or materials where appropriate, or white and light colored paints. Glazing can also be added to windows to reduce the amount of heat that buildings or roofs generate and store.[39]
Making urban spaces greener and more water retentive can also help mitigate the UHI effect. Green roofs boost urban resilience by reducing the urban heat island effect. Additionally, green roofs improve the resilience to urban flooding. Restoring ponds ponds and lakes and other types of urban open water can also help as shown by Beijing, China's "Dragon-shaped Lake".[40] Depaving of urban footpaths and roads has also been found to be effective in urban flood control, and may be a more cost-efficient approach.
Social strategies
There are various strategies to increase the resilience of those most vulnerable to urban heat waves. As established, these vulnerable citizens are primarily socially isolated seniors. Other vulnerable groups include young children (especially those facing abject poverty or living in informal housing), people with underlying health problems, the infirm or disabled and the homeless. Accurate and early prediction of heat waves is of fundamental importance, as it gives time for the government to issue extreme heat alerts. Urban areas must prepare and be ready to implement heat-wave emergency response initiatives. Seasonal campaigns aimed to educate the public on the risks associated with heat waves will help prepare the broad community, but in response to impending heat events more direct action is required.[41]
Local government must quickly communicate with the groups and institutions that work with heat-vulnerable populations. Cooling centres should be opened in libraries, community centres and government buildings. These centres ensure free access to air conditioning and water. In partnership with government and non-government social services, paramedics, police, firefighters, nurses and volunteers; the above-mentioned groups working with vulnerable populations should carry out regular door-to-door visits during these extreme heat scenarios. These visits should provide risk assessment, advice, bottled water (for areas without potable tap water) and the offer of free transportation to local cooling centres.[42]
Heat waves and droughts can reap massive damage on agricultural areas vital to providing food staples to urban populations. Reservoirs and aquifers quickly dry up due to increased demand on water for drinking, industrial and agricultural purposes. The result can be shortages and price spikes for food and with increasing frequency, shortages of drinking water as observed with increasing severity seasonally in China[43] and throughout most of the developing world.[44] From an agricultural standpoint, farmers can be required to plant more heat and drought-resistant crops. Agricultural practices can also be streamlined to higher levels of hydrological efficiency. Reservoirs should be expanded and new reservoirs and water towers should be constructed in areas facing critical shortages.[45] Grander schemes of damming and redirecting rivers should also be considered if possible. For saltwater coastal cities, desalination plants provide a possible solution to water shortages. Infrastructure also plays a role in resilience, as in many areas aging pipelines result in leakage and possible contamination of drinking water. In Kenya’s major cities, Nairobi and Mombasa, between 40 and 50% of drinking water is lost through leakage.[46] In these types of cases, replacements and repairs are clearly needed.
Flooding
Flooding, either from weather events, rising sea levels or infrastructure failures are a major cause of death, disease and economic losses throughout the world. Climate change and rapidly expanding urban settlements are two factors that are leading to the increasing occurrence and severity of urban flood events, especially in the developing world.[47][48][49]Storm surges can affect coastal cities and are caused by low pressure weather systems, like cyclones and hurricanes.[50] Flash floods and river floods can affect any city within a floodplain or with inadequate drainage infrastructure. These can be caused by large quantities of rain or heavy rapid snow melt. With all forms of flooding, cities are increasingly vulnerable because of the large quantity of paved and concrete surfaces. These impermeable surfaces cause massive amounts of runoff and can quickly overwhelm the limited infrastructure of storm drains, flood canals and intentional floodplains. Many cities in the developing world simply have no infrastructure to redirect floodwaters whatsoever.[51] Around the world, floods kill thousands of people every year and are responsible for billions of dollars in damages and economic losses.[52] Flooding, much like heat waves and droughts, can also wreak havoc on agricultural areas, quickly destroying large amounts of crops. In cities with poor or absent drainage infrastructure, flooding can also lead to the contamination of drinking water sources (aquifers, wells, inland waterways) with salt water, chemical pollution, and most frequently, viral and bacterial contaminants.[53]
Flood flow in urban environment
The flood flow in urbanised areas constitutes a hazard to the population and infrastructure. Some recent catastrophes included the inundations of Nîmes (France) in 1998 and Vaison-la-Romaine (France) in 1992, the flooding of New Orleans (USA) in 2005, the flooding in Rockhampton, Bundaberg, Brisbane during the 2010–2011 summer in Queensland (Australia). Flood flows in urban environments have been studied relatively recently despite many centuries of flood events.[51] Some researchers mentioned the storage effect in urban areas. Several studies looked into the flow patterns and redistribution in streets during storm events and the implication in terms of flood modelling.[54]
Some research considered the criteria for safe evacuation of individuals in flooded areas.[55] But some recent field measurements during the 2010–2011 Queensland floods showed that any criterion solely based upon the flow velocity, water depth or specific momentum cannot account for the hazards caused by the velocity and water depth fluctuations.[51] These considerations ignore further the risks associated with large debris entrained by the flow motion.[55]
Adapting for flood resilience
Urban greening
Replacing as many non-porous surfaces with green space as possible will create more areas for natural ground (and plant-based) absorption of excess water.[56] Gaining popularity are different types of green roofs. Green roofs vary in their intensity, from very thin layers of soil or rockwool supporting a variety of low or no-maintenance mosses or sedum species to large, deep, intensive roof gardens capable of supporting large plants and trees but requiring regular maintenance and more structural support.[57] The deeper the soil, the more rainwater it can absorb and therefore the more potential floodwater it can prevent from reaching the ground. One of the best strategies, if possible, is to simply create enough space for the excess water. This involves planning or expanding areas of parkland in or adjacent to the zone where flooding is most likely to occur. Excess water is diverted into these areas when necessary, as in Cardiff, Wales around the new Millennium Stadium and at the main Olympic site in Beijing, China .[58][59] Floodplain clearance is another greening strategy that fundamentally removes structures and pavement built on floodplains and returns them to their natural habitat which is capable of absorbing massive quantities of water that otherwise would have flooded the built urban area.[53]
Flood-water control
Levees and other flood barriers are indispensable for cities on floodplains or along rivers and coasts. In areas with lower financial and engineering capital, there are cheaper and simpler options for flood barriers. UK engineers are currently conducting field tests of a new technology called the SELOC (Self-Erecting Low-Cost Barrier). The barrier itself lies flat on the ground, and as the water rises, the SELOC floats up, with its top edge rising with the water level. A restraint holds the barrier in the vertical position. This simple, inexpensive flood barrier has great potential for increasing urban resilience to flood events[58] and shows significant promise for developing nations with its low cost and simple, fool-proof design. The creation or expansion of flood canals and/or drainage basins can help direct excess water away from critical areas[60] and the utilisation of innovative porous paving materials on city streets and car parks allow for the absorption and filtration of excess water.[39]
During the January 2011 flood of the Brisbane River (Australia), some unique field measurements about the peak of the flood showed very substantial sediment fluxes in the Brisbane River flood plain, consistent with the murky appearance of floodwaters.[61][62] The field deployment in an inundated street of the CBD showed also some unusual features of flood flow in an urban environment linked with some local topographic effects.
Structural resilience
In most developed nations, all new developments are assessed for flood risks. The aim is to ensure flood risk is taken into account in all stages of the planning process to avoid inappropriate development in areas of high risk. When development is required in areas of high risk, structures should be built to flood-resistant standards and living or working areas should be raised well above the worst-case scenario flood levels. For existing structures in high-risk areas, funding should be allocated to i.e. raise the electrical wiring/sockets so any water that enters the home can not reach the electrics. Other solutions are to raise these structures to appropriate heights[63] or make them floating[64] or considerations should be made to relocate or rebuild structures on higher ground. A house in Mexico Beach, Florida which survived Hurricane Michael is an example of a house built to survive tidal surge.[65]
The pre-Incan Uru people of Lake Titicaca in Peru have lived on floating islands made of reeds for hundreds of years. The practice began as an innovative form of protection from competition for land by various groups, and it continues to support the Uru homeland. The manual technique is used to build homes resting on hand-made islands[66] all from simple reeds from the totora plant. Similarly, in the southern wetlands of Iraq, the Marsh Arabs (Arab al-Ahwār) have lived for centuries on floating islands and in arched buildings[67] all constructed exclusively from the local qasab reeds. Without any nails, wood, or glass, buildings are assembled by hand as quickly as within a day. Another aspect of these villages, called Al Tahla, is that the built homes can also be disassembled in a day, transported, and reassembled .
Emergency response
As with all disasters, flooding requires a specific set of disaster response plans. Various levels of contingency planning should be established, from basic medical and selective evacuation provisions involving local emergency responders right the way up to full military disaster relief plans involving air-based evacuations, search and rescue teams and relocation provisions for entire urban populations. Clear lines of responsibility and chains of command must be laid out, and tiered priority response levels should be established to address the immediate needs of the most vulnerable citizens first. For post-flooding repair and reconstruction sufficient emergency funding should be set aside proactively.[68]
World education and research relating to urban resilience
China's resilient cities research started relatively late, with a series of theories, scholars, and disciplines mostly coming from the United States. However, with the establishment of China's Ministry of Emergency Management and the country's deepening awareness of and emphasis on earthquake prevention and mitigation, related research and institutions have developed rapidly. A number of universities, including Zhejiang University's Ren Center for Resilience, have made significant contributions to the promotion and application of resilient cities concepts in China.
Challenges with Further Mainstreaming of Urban Resilience Approaches
There are at least three key challenges with further mainstreaming innovative approaches to urban resilience. First, urban development systems have tended to see urban resilience schemes as public projects, entailing a significant burden on the state to finance, plan and manage them. This is a classic problem of "externalities" which private developers are too often not required to bear. Second, urban planning regulations typically do not require urban resilience measures in the same way they require fire detection and suppression or road access. Third, too many professionals in urban design, engineering and the environmental sciences lack awareness of innovative approaches to resilience and so cannot practice them.[69]
A disaster is a serious problem that happens over a period of time and causes so much harm to people, things, economies, or the environment that the affected community or society cannot handle it on its own. In theory, natural disasters are those caused by natural hazards, whereas human-made disasters are those caused by human hazards. However, in modern times, the divide between natural, human-made or human-accelerated disasters is more and more difficult to draw. In fact, all disasters can be seen as human-made, due to human failure to introduce appropriate emergency management measures.
A natural disaster is the highly harmful impact on a society or community following a natural hazard event. Some examples of natural hazard events include: flooding, drought, earthquake, tropical cyclone, lightning, tsunami, volcanic activity, wildfire. A natural disaster can cause loss of life or damage property, and typically leaves economic damage in its wake. The severity of the damage depends on the affected population's resilience and on the infrastructure available. Scholars have been saying that the term natural disaster is unsuitable and should be abandoned. Instead, the simpler term disaster could be used, while also specifying the category of hazard. A disaster is a result of a natural or human-made hazard impacting a vulnerable community. It is the combination of the hazard along with exposure of a vulnerable society that results in a disaster.
Climate change adaptation is the process of adjusting to the effects of climate change. These can be both current or expected impacts. Adaptation aims to moderate or avoid harm for people, and is usually done alongside climate change mitigation. It also aims to exploit opportunities. Humans may also intervene to help adjustment for natural systems. There are many adaptation strategies or options. They can help manage impacts and risks to people and nature. The four types of adaptation actions are infrastructural, institutional, behavioural and nature-based options.
Disaster risk reduction (DRR) is an approach for planning and taking steps to make disasters less likely to happen, and less damaging when they do happen. DRR aims to make communities stronger and better prepared to handle disasters. When DRR is successful, it decreases the vulnerability of communities because it mitigates the effects of disasters. This means DRR can reduce the severity and number of risky events. Since climate change can increase climate hazards, DRR and climate change adaptation are often looked at together in development efforts.
The aim of water security is to make the most of water's benefits for humans and ecosystems. The second aim is to limit the risks of destructive impacts of water to an acceptable level. These risks include for example too much water (flood), too little water or poor quality (polluted) water. People who live with a high level of water security always have access to "an acceptable quantity and quality of water for health, livelihoods and production". For example, access to water, sanitation and hygiene services is one part of water security. Some organizations use the term water security more narrowly for water supply aspects only.
Climate change is a critical issue in Bangladesh as the country is one of the most vulnerable to the effects of climate change. In the 2020 edition of Germanwatch's Climate Risk Index, it ranked seventh in the list of countries most affected by climate calamities during the period 1999–2018. Bangladesh's vulnerability to the effects of climate change is due to a combination of geographical factors, such as its flat, low-lying, and delta-exposed topography, and socio-economic factors, including its high population density, levels of poverty, and dependence on agriculture. The impacts and potential threats include sea level rise, temperature rise, food crises, droughts, floods, and cyclones.
National Innovations in Climate Resilient Agriculture (NICRA) was launched during February 2011 by the Indian Council of Agricultural Research (ICAR) with the funding from the Ministry of Agriculture, Government of India. The mega project has three major objectives of strategic research, technology demonstrations and capacity building. Assessment of the impact of climate change simultaneous with formulation of adaptive strategies is the prime approach under strategic research across all sectors of agriculture, dairying and fisheries.
The Climate and Development Knowledge Network (CDKN) works to enhance the quality of life for the poorest and most vulnerable to climate change. CDKN does this by combining research, advisory services and knowledge management in support of locally owned and managed policy processes. It works in partnership with decision-makers in the public, private and non-governmental sectors nationally, regionally and globally.
In the fields of engineering and construction, resilience is the ability to absorb or avoid damage without suffering complete failure and is an objective of design, maintenance and restoration for buildings and infrastructure, as well as communities. A more comprehensive definition is that it is the ability to respond, absorb, and adapt to, as well as recover in a disruptive event. A resilient structure/system/community is expected to be able to resist to an extreme event with minimal damages and functionality disruptions during the event; after the event, it should be able to rapidly recovery its functionality similar to or even better than the pre-event level.
Climate resilience is a concept to describe how well people or ecosystems are prepared to bounce back from certain climate hazard events. The formal definition of the term is the "capacity of social, economic and ecosystems to cope with a hazardous event or trend or disturbance". For example, climate resilience can be the ability to recover from climate-related shocks such as floods and droughts. Methods of coping include suitable responses to maintain relevant functions of societies and ecosystems. To increase climate resilience means one has to reduce the climate vulnerability of people and countries. Efforts to increase climate resilience include a range of social, economic, technological, and political strategies. They have to be implemented at all scales of society, from local community action all the way to global treaties.
Community resilience is the sustained ability of a community to use available resources to respond to, withstand, and recover from adverse situations. This allows for the adaptation and growth of a community after disaster strikes. Communities that are resilient are able to minimize any disaster, making the return to normal life as effortless as possible. By implementing a community resilience plan, a community can come together and overcome any disaster, while rebuilding physically and economically.
Nature-based solutions is the sustainable management and use of natural features and processes to tackle socio-environmental issues. These issues include for example climate change, water security, food security, preservation of biodiversity, and disaster risk reduction. Through the use of NBS healthy, resilient, and diverse ecosystems can provide solutions for the benefit of both societies and overall biodiversity. The 2019 UN Climate Action Summit highlighted nature-based solutions as an effective method to combat climate change. For example, NBS in the context of climate action can include natural flood management, restoring natural coastal defences, providing local cooling, restoring natural fire regimes.
Climate change in Indiana encompasses the effects of climate change, attributed to man-made increases in atmospheric carbon dioxide, in the U.S. state of Indiana.
Climate change is having serious impacts in the Philippines such as increased frequency and severity of natural disasters, sea level rise, extreme rainfall, resource shortages, and environmental degradation. All of these impacts together have greatly affected the Philippines' agriculture, water, infrastructure, human health, and coastal ecosystems and they are projected to continue having devastating damages to the economy and society of the Philippines.
Climate change is posing an increasing threat to global socio-economic development and environmental sustainability. Developing countries with low adaptive capacity and high vulnerability to the phenomenon are disproportionately affected. Climate change in Kenya is increasingly impacting the lives of Kenya's citizens and the environment. Climate Change has led to more frequent extreme weather events like droughts which last longer than usual, irregular and unpredictable rainfall, flooding and increasing temperatures.
Sustainable Development Goal 11, titled "sustainable cities and communities", is one of 17 Sustainable Development Goals established by the United Nations General Assembly in 2015. The official mission of SDG 11 is to "Make cities inclusive, safe, resilient and sustainable". The 17 SDGs take into account that action in one area will affect outcomes in other areas as well, and that development must balance social, economic and environmental sustainability.
Climate change and cities are deeply connected. Cities are one of the greatest contributors and likely best opportunities for addressing climate change. Cities are also one of the most vulnerable parts of the human society to the effects of climate change, and likely one of the most important solutions for reducing the environmental impact of humans. The UN projects that 68% of the world population will live in urban areas by 2050. In the year 2016, 31 mega-cities reported having at least 10 million in their population, 8 of which surpassed 20 million people. However, secondary cities - small to medium size cities are rapidly increasing in number and are some of the fastest growing urbanizing areas in the world further contributing to climate change impacts. Cities have a significant influence on construction and transportation—two of the key contributors to global warming emissions. Moreover, because of processes that create climate conflict and climate refugees, city areas are expected to grow during the next several decades, stressing infrastructure and concentrating more impoverished peoples in cities.
Climate change vulnerability is a concept that describes how strongly people or ecosystems are likely to be affected by climate change. Its formal definition is the "propensity or predisposition to be adversely affected" by climate change. It can apply to humans and also to natural systems. Issues around the capacity to cope and adapt are also part of this concept. Vulnerability is a component of climate risk. Vulnerability differs within communities and also across societies, regions, and countries. It can increase or decrease over time.
Climate change adaptation in the Philippines is being incorporated into development plans and policies that specifically target national and local climate vulnerabilities. As a developing country and an archipelago, the Philippines is particularly vulnerable to a variety of climatic threats like intensifying tropical cyclones, drastic changes in rainfall patterns, rising sea levels, and rising temperatures. According to the UN Office for the Coordination of Humanitarian Affairs (OCHA), the Philippines is one of the most disaster-prone countries in the world. In 2021, the Global Climate Risk Index ranked the Philippines fourth of the ten countries most affected between the years 2000 and 2019. The need for managing climate risks through climate change adaptation has become increasingly evident. Adaptation can reduce, moderate or avoid current and expected climate effects or take advantage of beneficial climatic events. Developing greater resilience to various threats can be a major goal of comprehensive disaster risk reduction strategy. The Philippines is therefore working on a number of national and local adaptation and disaster risk reduction strategies to build the country's climate resilience.
Climate shelters are a place of refuge for populations that seek shelter from extreme climate events exacerbated by the effects of urban heat islands. They include cooling centers, but also encompass parks and other outdoor spaces designed to provide a harbor for cooler temperatures than surrounding areas. Several cities have designed programs to implement urban climate shelters.
↑ J. R. McNeill; Richard P. Tucker; Simo Laakkonen; Timo Vuorisalo, eds. (2019). The Resilient City in World War II. Springer International Publishing. p.9. ISBN9783030174392.
↑ J. R. McNeill; Richard P. Tucker; Simo Laakkonen; Timo Vuorisalo, eds. (2019). The Resilient City in World War II. Springer International Publishing. p.8. ISBN9783030174392.
↑ J. R. McNeill; Richard P. Tucker; Simo Laakkonen; Timo Vuorisalo, eds. (2019). The Resilient City in World War II. Springer International Publishing. p.9. ISBN9783030174392.
↑ J. R. McNeill; Richard P. Tucker; Simo Laakkonen; Timo Vuorisalo, eds. (2019). The Resilient City in World War II. Springer International Publishing. p.10. ISBN9783030174392.
↑ J. R. McNeill; Richard P. Tucker; Simo Laakkonen; Timo Vuorisalo, eds. (2019). The Resilient City in World War II. Springer International Publishing. p.12. ISBN9783030174392.
↑ Coaffee, J (2008). "Risk, resilience, and environmentally sustainable cities". Energy Policy. 36 (12): 4633–4638. doi:10.1016/j.enpol.2008.09.048.
↑ Pickett, S. T. A.; Cadenasso, M. L.; etal. (2004). "Resilient cities: meaning, models, and metaphor for integrating the ecological, socio-economic, and planning realms". Landscape and Urban Planning. 69 (4): 373. doi:10.1016/j.landurbplan.2003.10.035.
↑ Shashua-Bar, L.; Hoffman, M. E. (2000). "Vegetation as a climatic component in the design of an urban street: An empirical model for predicting the cooling effect of urban green areas with trees". Energy and Buildings. 31 (3): 229. doi:10.1016/s0378-7788(99)00018-3.
↑ Zhou, Xiaoqin; Li, Zifu; Staddon, Chad; Wu, Xuejun; Song, Han (19 May 2017). "Issues and challenges of reclaimed water usage: a case study of the dragon-shaped river in the Beijing Olympic Park". Water International. 42 (4): 486-494. doi:10.1080/02508060.2017.1331409.
↑ Ivey, J. L.; Smithers, J.; etal. (2004). "Community Capacity for Adaptation to Climate-Induced Water Shortages: Linking Institutional Complexity and Local Actors". Environmental Management. 33 (1): 36–47. doi:10.1007/s00267-003-0014-5. PMID14743290. S2CID13597786.
↑ IPCC (2001). Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. p.881.
↑ IPCC (2007). Climate Change 2007: Impacts, Adaptation and Vulnerability. Summary for Policymakers. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press.
↑ Mentens, J.; Raes, D.; etal. (2006). "Green roofs as a tool for solving the rainwater runoff problem in the urbanized 21st century?". Landscape and Urban Planning. 77 (3): 221. doi:10.1016/j.landurbplan.2005.02.010.
↑ Zhou, Xiaoqin; Li, Zifu; Staddon, Chad; Wu, Xuejun; Song, Han (19 May 2017). "Issues and challenges of reclaimed water usage: a case study of the dragon-shaped river in the Beijing Olympic Park". Water International. 42 (4): 486–494. doi:10.1080/02508060.2017.1331409.
↑ Colten, C. E.; Kates, R. W.; Laska, S. B. Community resilience: Lessons from New Orleans and Hurricane Katrina. Oak Ridge National Laboratory, Oak Ridge. CiteSeerX10.1.1.172.1958.{{cite book}}: |work= ignored (help)
↑ Coaffee, J.; D. Murakami Wood; etal. (2009). The Everyday resilience of the city: how cities respond to terrorism and disaster. Basingstoke, UK: Palgrave Macmillan.
↑ Zuniga-Teran, Adriana A.; Staddon, Chad; de Vito, Laura; Gerlak, Andrea K.; Ward, Sarah; Schoeman, Yolandi; Hart, Aimee; Booth, Giles (20 March 2020). "Challenges of mainstreaming green infrastructure in built environment professions". Journal of Environmental Planning and Management. 63 (4): 710–732. doi:10.1080/09640568.2019.1605890.
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