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".
163-413: 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. According to the urban historian Roger W. Lotchin , World War II had
326-601: A microorganism , virus or toxin (from a biological source) that can affect health . Many biological hazards are associated with food, including certain viruses , parasites , fungi , bacteria , and plant and seafood toxins . Pathogenic Campylobacter and Salmonella are common foodborne biological hazards. The hazards from these bacteria can be avoided through risk mitigation steps such as proper handling, storing , and cooking of food. Diseases can be enhanced by human factors such as poor sanitation or by processes such as urbanization . A chemical can be considered
489-672: A society are floods , droughts , earthquakes , tropical cyclones , lightning strikes , volcanic activity and wildfires . Technological and anthropogenic hazards include, for example, structural collapses , transport accidents , accidental or intentional explosions , and release of toxic materials. The term climate hazard is used in the context of climate change . These are hazards that stem from climate-related events and can be associated with global warming , such as wildfires, floods, droughts, sea level rise . Climate hazards can combine with other hazards and result in compound event losses (see also loss and damage ). For example,
652-589: 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. Medellin in Colombia qualified for the urban resilience challenge in 2013. In 2016, it won the Lee Kuan Yew World City Prize . A core factor enabling progress on all other dimensions of urban resilience is urban governance . Sustainable, resilient and inclusive cities are often
815-475: A central role in the existence of natural hazards because "it is only when people and their possessions get in the way of natural processes that hazard exists". A natural hazard can be considered as a geophysical event when it occurs in extremes and a human factor is involved that may present a risk. There may be an acceptable variation of magnitude which can vary from the estimated normal or average range with upper and lower limits or thresholds. In these extremes,
978-478: A century ago. As a result, the world urban population growth curve has up till recently followed a quadratic-hyperbolic pattern. From the development of the earliest cities in Indus valley civilization , Mesopotamia and Egypt until the 18th century, an equilibrium existed between the vast majority of the population who were engaged in subsistence agriculture in a rural context, and small centres of populations in
1141-432: 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 impact by supporting innovation and promoting efficiencies in urban infrastructure, thus leading to lower-cost city services. The deployment of new technologies in
1304-435: A community that exceed its capacity to cope using its own resources. Disasters can be caused by natural, man-made and technological hazards, as well as various factors that influence the exposure and vulnerability of a community." The US Federal Emergency Management Agency (FEMA) explains the relationship between natural disasters and natural hazards as follows: "Natural hazards and natural disasters are related but are not
1467-552: A cumulative biological effect, while others are metabolically eliminated over time. Other chemical hazards may depend on concentration or total quantity for their effects. Some harmful chemicals occur naturally in certain geological formations, such as arsenic . Other chemicals include products with commercial uses, such as agricultural and industrial chemicals, as well as products developed for home use. A variety of chemical hazards have been identified. However, every year companies produce more new chemicals to fill new needs or to take
1630-590: A day, transported, and reassembled. 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
1793-536: A farmer was described as "hot and exhausting". "Everyone says the farmer works the hardest but gets the least amount of money". In an effort to counter this impression, the Agriculture Department of Thailand is seeking to promote the impression that farming is "honorable and secure". However, in Thailand, urbanization has also resulted in massive increases in problems such as obesity. Shifting from
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#17327731143881956-451: 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
2119-521: A greater risk for obesity, diabetes and related chronic disease. Overall, body mass index and cholesterol levels increase sharply with national income and the degree of urbanization. [40] Food deserts in the United States are most commonly found in low-income and predominately African American neighbourhoods. One study on food deserts in Denver , Colorado found that, in addition to minorities,
2282-535: A grocery store are associated with higher rates of obesity and other health disparities. Food deserts in developed countries often correspond to areas with a high density of fast food chains and convenience stores that offer little to no fresh food. Urbanization has been shown to be associated with the consumption of less fresh fruits, vegetables, and whole grains and a higher consumption of processed foods and sugar-sweetened beverages. Poor access to healthy food and high intakes of fat, sugar and salt are associated with
2445-451: A growing increase for addressing other areas of life cycle consumption has occurred from initial stage reduction to heat recovery and recycling of materials. For example, concerns for mass consumption and fast fashion have moved to the forefront of the urban consumers' priorities. Aside from environmental concerns (e.g. climate change effects), other urban concerns for waste management are public health and land access. Urbanization can have
2608-540: A hazard if by its intrinsic properties it can cause harm or danger to humans, property, or the environment. Health hazards associated with chemicals are dependent on the dose or amount of the chemical. For example, iodine in the form of potassium iodate is used to produce iodised salt . When applied at a rate of 20 mg of potassium iodate per 1000 mg of table salt, the chemical is beneficial in preventing goitre , while iodine intakes of 1200–9500 mg in one dose has been known to cause death. Some chemicals have
2771-459: A higher content of meat, sugars, refined grains and fats. Urban residents typically have reduced time available for at-home food preparation combined with increased disposable income, facilitating access to convenience foods and ready-to-eat meals. One such effect is the formation of food deserts . Nearly 23.5 million people in the United States lack access to supermarkets within one mile of their home. Several studies suggest that long distances to
2934-573: A large effect on biodiversity by causing a division of habitats and thereby alienation of species, a process known as habitat fragmentation . Habitat fragmentation does not destroy the habitat, as seen in habitat loss , but rather breaks it apart with things like roads and railways This change may affect a species ability to sustain life by separating it from the environment in which it is able to easily access food, and find areas that they may hide from predation With proper planning and management, fragmentation can be avoided by adding corridors that aid in
3097-440: 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. Storm surges can affect coastal cities and are caused by low pressure weather systems, like cyclones and hurricanes. Flash floods and river floods can affect any city within
3260-651: A means for disaster risk reduction. In September 2015, world leaders adopted the 17 Sustainable Development Goals (SDGs) as part of the 2030 Agenda for Sustainable Development. The goals, which build on and replace the Millennium Development Goals , 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
3423-494: A mechanical hazard. Hazard identification of new machines and/or industrial processes occurs at various stages in the design of the new machine or process. These hazard identification studies focus mainly on deviations from the intended use or design and the harm that may occur as a result of these deviations. These studies are regulated by various agencies such as the Occupational Safety and Health Administration and
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#17327731143883586-473: A more acidic environment. Rapid growth of communities creates new challenges in the developed world and one such challenge is an increase in food waste also known as urban food waste. Food waste is the disposal of food products that can no longer be used due to unused products, expiration, or spoilage. The increase of food waste can raise environmental concerns such as increase production of methane gases and attraction of disease vectors . Landfills are
3749-406: A more cost-efficient approach. 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
3912-423: A natural phenomenon, earthquakes can sometimes be induced by human interventions, such as injection wells , large underground nuclear explosions , excavation of mines , or reservoirs . Anthropogenic hazards, or human-induced hazards, are "induced entirely or predominantly by human activities and choices". These can be societal, technological or environmental hazards . Technological hazards are created by
4075-584: A negative impact on population health particularly affecting people's susceptibility to asthma. In low and middle income countries many factors contribute to the high numbers of people with asthma. Similar to areas in the United States with increasing urbanization, people living in growing cities in low income countries experience high exposure to air pollution, which increases the prevalence and severity of asthma among these populations. Links have been found between exposure to traffic-related air pollution and allergic diseases. Children living in poor, urban areas in
4238-645: 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 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 and
4401-462: 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. In these types of cases, replacements and repairs are clearly needed. Flooding, either from weather events, rising sea levels or infrastructure failures are
4564-627: A profound environmental impact on urban areas in the USA. By 1945 Pittsburgh and other cities along the Mississippi River had 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. Extreme cases of hard hit cities include Hiroshima , Chongqing , Stalingrad , and Dresden . Environmental history first emerged as an academic research topic in
4727-646: A result of individual, collective and state action. Living in a city can be culturally and economically beneficial since it can provide greater opportunities for access to the labour market, better education, housing, and safety conditions, and reduce the time and expense of commuting and transportation. Conditions like density, proximity, diversity, and marketplace competition are elements of an urban environment that deemed beneficial. However, there are also harmful social phenomena that arise: alienation, stress, increased cost of living, and mass marginalization that are connected to an urban way of living. Suburbanization , which
4890-408: A rural environment to an urbanized community also caused a transition to a diet that was mainly carbohydrate-based to a diet higher in fat and sugar, consequently causing a rise in obesity. City life, especially in modern urban slums of the developing world, is certainly hardly immune to pestilence or climatic disturbances such as floods, yet continues to strongly attract migrants. Examples of this were
5053-704: A variety of measures have been taken to limit human exposure to these microorganisms through food safety, good personal hygiene, and education. The potential for new biological hazards also exists through the discovery of new microorganisms and the development of new genetically modified (GM) organisms. The use of new GM organisms is regulated by various governmental agencies. The US Environmental Protection Agency (EPA) controls GM plants that produce or resist pesticides (i.e. Bt corn and Roundup ready crops ). The US Food and Drug Administration (FDA) regulates GM plants that will be used as food or for medicinal purposes. Biological hazards can include medical waste or samples of
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5216-567: A variety of negative effects on non-target organisms. DDT can build up, or bioaccumulate, in birds, resulting in thinner-than-normal eggshells, which can break in the nest. The organochlorine pesticide dieldrin has been linked to Parkinson's disease . Corrosive chemicals like sulfuric acid , which is found in car batteries and research laboratories, can cause severe skin burns. Many other chemicals used in industrial and laboratory settings can cause respiratory, digestive, or nervous system problems if they are inhaled, ingested, or absorbed through
5379-543: A vector to spread to humans. An example of this could be dengue fever. Urbanization has also been associated with an increased risk of asthma as well. Throughout the world, as communities transition from rural to more urban societies, the number of people affected by asthma increases. The odds of reduced rates of hospitalization and death from asthmas has decreased for children and young adults in urbanized municipalities in Brazil. This finding indicates that urbanization may have
5542-478: Is a common effect of urbanization. Precipitation from rooftops, roads, parking lots and sidewalks flows to storm drains , instead of percolating into groundwater . The contaminated stormwater in the drains is typically untreated and flows to nearby streams, rivers or coastal bays. Eutrophication in water bodies is another effect large populations in cities have on the environment. When rain occurs in these large cities, it filters CO 2 and other pollutants in
5705-571: 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: 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
5868-765: Is a potential source of harm . Substances, events, or circumstances can constitute hazards when their nature would potentially allow them to cause damage to health, life, property, or any other interest of value. The probability of that harm being realized in a specific incident , combined with the magnitude of potential harm, make up its risk . This term is often used synonymously in colloquial speech. Hazards can be classified in several ways which are not mutually exclusive. They can be classified by causing actor (for example, natural or anthropogenic ), by physical nature (e.g. biological or chemical ) or by type of damage (e.g., health hazard or environmental hazard ). Examples of natural disasters with highly harmful impacts on
6031-401: 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 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. In August 2003
6194-524: Is an example of a house built to survive tidal surge . 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 all from simple reeds from
6357-411: Is an extreme geophysical event that is capable of causing a disaster. 'Extreme' in this case means a substantial variation in either the positive or the negative direction from the normal trend; flood disasters can result from exceptionally high precipitation and river discharge, and drought is caused by exceptionally low values. The fundamental determinants of hazard and the risk of such hazards occurring
6520-437: Is because modern technological living uses certain toxic or poisonous materials in the electronics and chemical industries. Which, when they are in use or transported, are usually safely contained or encapsulated and packaged to avoid any exposure. In the waste stream, the waste products exterior or encapsulation breaks or degrades and there is a release and exposure to hazardous materials into the environment, for people working in
6683-423: Is chaired by UN-Habitat. 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
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6846-411: Is compulsory to promote a fair society. Furthermore, urbanization improves environmental eminence through superior facilities and standards in urban areas as compared to rural areas. Lastly, urbanization curbs pollution emissions by increasing innovations. In his 2009 book Whole Earth Discipline , Stewart Brand argues that the effects of urbanization are primarily positive for the environment. First,
7009-462: Is crucial. Frameworks for disaster risk management , for example, offer practical opportunities for enhancing resilience. 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. 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 in
7172-754: 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
7335-476: Is happening in the cities of the largest developing countries, may be regarded as an attempt to balance these harmful aspects of urban life while still allowing access to the large extent of shared resources. In cities, money, services, wealth and opportunities are centralized. Many rural inhabitants come to the city to seek their fortune and alter their social position. Businesses, which provide jobs and exchange capital, are more concentrated in urban areas. Whether
7498-419: Is listed here as a climate hazard is because "warming temperatures may result in higher evapotranspiration , in turn leading to drier soils". Waterborne diseases are also connected to climate hazards. Climate hazards can combine with other hazards and result in compound event losses (see also loss and damage ). For example, the climate hazard of heat can combine with the hazard of poor air quality. Or
7661-566: Is predicted to generate artificial scarcities of land, lack of drinking water, playgrounds and so on for most urban dwellers. The predicted urban population growth is equivalent to approximately 3 billion urbanites by 2050, much of which will occur in Africa and Asia . Notably, the United Nations has also recently projected that nearly all global population growth from 2017 to 2030 will be by cities, with about 1.1 billion new urbanites over
7824-417: Is required. 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;
7987-485: Is timing, location, magnitude and frequency. For example, magnitudes of earthquakes are measured on the Richter scale from 1 to 10, whereby each increment of 1 indicates a tenfold increase in severity. The magnitude-frequency rule states that over a significant period of time many small events and a few large ones will occur. Hurricanes and typhoons on the other hand occur between 5 degrees and 25 degrees north and south of
8150-734: Is tracking the most recent efforts to build urban resilience as well as the actors behind these actions and a number of case studies. 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
8313-520: Is used in the context of climate change , for example in the IPCC Sixth Assessment Report . These are hazards that stem from climate-related events such as wildfires , floods, droughts, sea level rise . Climate hazards in the context of water include: Increased temperatures, changes in rainfall patterns between the wet and dry season (increased rainfall variability) and sea level rise. The reason why increasing temperatures
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#17327731143888476-404: Is whether this is due to agglomeration effects or whether cities simply attract those who are more productive. Urban geographers have shown that there exists a large productivity gain due to locating in dense agglomerations. It is thus possible that agents locate in cities in order to benefit from these agglomeration effects. The dominant conurbation (s) of a country can get more benefits from
8639-479: Is working in a collaborative model in six pilot cities: Accra, Bogotá, Jakarta, Maputo, Mexico City and New York City. 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
8802-430: The 2011 Thailand floods and 2007 Jakarta flood . Urban areas are also far more prone to violence , drugs , and other urban social problems. In the United States, industrialization of agriculture has negatively affected the economy of small and middle-sized farms and strongly reduced the size of the rural labour market. – Madhura Swaminathan, economist at Kolkata's Indian Statistical Institute Particularly in
8965-554: The 2011 Tohoku earthquake and tsunami , and Hurricane Sandy in 2012. Two of the more well-recognized programs are Harvard Graduate School of Design 's Master's program in Risk and Resilience, and Tulane University 's Disaster Resilience Leadership Academy. There are also several workshops available related to the U.S. Federal Emergency Management Agency and the Department of Homeland Security . China Hazard A hazard
9128-509: The National Highway Traffic Safety Administration . Engineering hazards occur when human structures fail (e.g. building or structural collapse , bridge failures , dam failures ) or the materials used in their construction prove to be hazardous. Societal hazards can arise from civil disorders , explosive remnants of war , violence , crowd accidents , financial crises , etc. However,
9291-660: The Overseas Development Institute have proposed policies that encourage labour-intensive to make use of the migration of less skilled workers. One problem these migrant workers are involved with is the growth of slums . In many cases, the rural-urban unskilled migrant workers are attracted by economic opportunities in cities. Unfortunately, they cannot find a job and or pay for houses in urban areas and have to live in slums. Urban problems, along with developments in their facilities, are also fuelling suburb development trends in less developed nations, though
9454-710: 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. The index
9617-482: The United Nations Office for Disaster Risk Reduction (UNDRR) Hazard Definition & Classification Review (Sendai Framework 2015 - 2030) specifically excludes armed conflict from the anthropogenic hazard category, as these hazards are already recognised under international humanitarian law. In managing waste many hazardous materials are put in the domestic and commercial waste stream . In part this
9780-502: The city centre for the working class . Urbanization rapidly spread across the Western world and, since the 1950s, it has begun to take hold in the developing world as well. At the turn of the 20th century, just 15% of the world population lived in cities. According to the UN , the year 2007 witnessed the turning point when more than 50% of the world population were living in cities, for
9943-433: The likelihood or probability of a given hazard of a given level causing a particular level of loss of damage. The elements of risk are populations, communities, the built environment , the natural environment , economic activities and services which are under threat of disaster in a given area. Another definition of risk is "the probable frequency and probable magnitude of future losses". This definition also focuses on
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#173277311438810106-408: The sociological process of rationalization . Urbanization can be seen as a specific condition at a set time (e.g. the proportion of total population or area in cities or towns), or as an increase in that condition over time. Therefore, urbanization can be quantified either in terms of the level of urban development relative to the overall population, or as the rate at which the urban proportion of
10269-596: The urban heat island effect . Urban heat island (UHI) refers to the presence of an inner-city micro-climate 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. 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
10432-405: The working class out of the market, including officials and employees of the local districts. For example, Eric Hobsbawm 's book The age of revolution: 1789–1848 (published 1962 and 2005) chapter 11, stated "Urban development in our period was a gigantic process of class segregation, which pushed the new labouring poor into great morasses of misery outside the centres of government, business, and
10595-577: The 1970s, focusing initially on rural areas . Pioneers of urban environmental history include Martin Melosi , Christine Rosen , Joel A. Tarr , Peter Brimblecombe , Bill Luckin , and Christopher Hamlin . 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
10758-567: The CBD showed also some unusual features of flood flow in an urban environment linked with some local topographic effects. 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
10921-605: The Earth's atmosphere as emissions increase with the rise in urban development. In fact, the ocean absorbs a quarter of the CO 2 produced by humans. This helps to lessen the harmful effects of greenhouse gases. But it also makes the ocean more acidic. A drop in pH the prevents the proper formation of calcium carbonate, which sea creatures need to build or keep shells or skeletons. This is especially true for many species of molluscs and coral. However, some species have been able to thrive in
11084-552: The FDA regulates new chemicals used in foods or as drugs. The potential hazards of these chemicals can be identified by performing a variety of tests before the authorization of usage. The number of tests required and the extent to which the chemicals are tested varies, depending on the desired usage of the chemical. Chemicals designed as new drugs must undergo more rigorous tests than those used as pesticides. Pesticides, which are normally used to control unwanted insects and plants, may cause
11247-592: 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. This heat wave claimed more than 40,000 lives across Europe. 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. The 2010 northern hemisphere summer heat wave
11410-582: The United States now have an increased risk of morbidity due to asthma in comparison to other low-income children in the United States. In addition, children with croup living in urban areas have higher hazard ratios for asthma than similar children living in rural areas. Researchers suggest that this difference in hazard ratios is due to the higher levels of air pollution and exposure to environmental allergens found in urban areas. Exposure to elevated levels of ambient air pollutants such as nitrogen dioxide (NO 2 ), carbon monoxide (CO), and particulate matter with
11573-814: 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. 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 and throughout most of
11736-559: 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". The professional services firm Arup has helped
11899-509: The affected neighbourhoods also had a high proportion of children and new births. In children, urbanization is associated with a lower risk of under-nutrition but a higher risk of being overweight . Urbanization has also been linked to the spread of communicable diseases, which can spread more rapidly in the favourable environment with more people living in a smaller area. Such diseases can be respiratory infections and gastrointestinal infections. Other infections could be infections, which need
12062-415: The aforementioned chemicals. In these ideal conditions, they choke surface water, blocking sunlight and nutrients from other life forms. Overgrowth of algal blooms makes water worse overall and disrupts the natural balance of aquatic ecosystems. Furthermore, as algal blooms die, CO 2 is produced. This makes the ocean more acidic, a process called acidification. The ocean's surface can absorb CO 2 from
12225-408: The air onto the ground. These chemicals are washed directly into rivers, streams, and oceans, making water worse and damaging ecosystems in them. Eutrophication is a process which causes low levels of oxygen in water and algal blooms that may harm aquatic life. Harmful algal blooms make dangerous toxins. They live best in nitrogen- and phosphorus-rich places which include the oceans contaminated by
12388-607: The amount of heat that buildings or roofs generate and store. 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". Depaving of urban footpaths and roads has also been found to be effective in urban flood control, and may be
12551-450: The birth rate of new urban dwellers falls immediately to replacement rate and keeps falling, reducing environmental stresses caused by population growth. Secondly, emigration from rural areas reduces destructive subsistence farming techniques, such as improperly implemented slash and burn agriculture. Alex Steffen also speaks of the environmental benefits of increasing the urbanization level in "Carbon Zero: Imagining Cities that can save
12714-573: The capital, are normal cities instead. A conurbation's dominance can be measured by output, wealth, and especially population, each expressed as a percentage of the entire country's. Greater Seoul is one conurbation that dominates South Korea. It is home to 50% of the entire national population. Though Greater Busan-Ulsan (15%, 8 million) and Greater Osaka (14%, 18 million) dominate their respective countries, their populations are moving to their even more dominant rivals, Seoul and Tokyo respectively. As cities develop, costs will skyrocket. This often takes
12877-400: The center of the Earth consists of molten material at very high temperatures which would be a severe hazard if contact was made with the core. However, there is no feasible way of making contact with the core, therefore the center of the Earth currently poses no hazard. The frequency and severity of hazards are important aspects for risk management . Hazards may also be assessed in relation to
13040-477: 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. 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
13203-406: 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. Trees are among
13366-664: The classification methods is by specifying the origin of the hazard. One key concept in identifying a hazard is the presence of stored energy that, when released, can cause damage. The stored energy can occur in many forms: chemical, mechanical, thermal, radioactive, electrical, etc. The United Nations Office for Disaster Risk Reduction (UNDRR) explains that "each hazard is characterized by its location, intensity or magnitude, frequency and probability". A distinction can also be made between rapid-onset natural hazards, technological hazards, and social hazards, which are described as being of sudden occurrence and relatively short duration, and
13529-420: The climate hazard flooding can combine with poor water quality. Climate scientists have pointed out that climate hazards affect different groups of people differently, depending on their climate change vulnerability : There are "factors that make people and groups vulnerable (e.g., poverty, uneven power structures, disadvantage and discrimination due to, for example, social location and the intersectionality or
13692-399: The climate hazard of heat can combine with the hazard of poor air quality. Or the climate hazard flooding can combine with poor water quality. In physics terms, common theme across many forms of hazards is the presence of energy that can cause damage, as it can happen with chemical energy , mechanical energy or thermal energy . This damage can affect different valuable interests, and
13855-798: The combination of ill-health and poverty entrenches disadvantage over time." Many of the urban poor have difficulty accessing health services due to their inability to pay for them; so they resort to less qualified and unregulated providers. While urbanization is associated with improvements in public hygiene , sanitation and access to health care , it also entails changes in occupational, dietary , and exercise patterns. It can have mixed effects on health patterns, alleviating some problems, and accentuating others. Traditionally, rural populations have tended to eat plant-based diets rich in grains, fruits and vegetables, and with low fat content. However, rural people migrating to urban areas often shift towards diets that rely more on processed foods characterized by
14018-741: The connection of areas and allow for easier movement around urbanized regions. Depending on the various factors, such as level of urbanization, both increases or decreases in "species richness" can be seen. This means that urbanization may be detrimental to one species but also help facilitate the growth of others. In instances of housing and building development, many times vegetation is completely removed immediately in order to make it easier and less expensive for construction to occur, thereby obliterating any native species in that area. Habitat fragmentation can filter species with limited dispersal capacity. For example, aquatic insects are found to have lower species richness in urban landscapes. The more urbanized
14181-463: The consequences of longer-term environmental degradation such as desertification and drought. Hazards may be grouped according to their characteristics. These factors are related to geophysical events, which are not process specific: Damage to valuable human interests can occur due to phenomena and processes of the natural environment . Natural disasters such as earthquakes , floods , volcanoes and tsunami have threatened people, society,
14344-431: The contamination of drinking water sources (aquifers, wells, inland waterways) with salt water, chemical pollution, and most frequently, viral and bacterial contaminants. The flood flow in urbanized 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,
14507-409: The criteria for safe evacuation of individuals in flooded areas. 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. These considerations ignore further the risks associated with large debris entrained by
14670-439: The developing world simply have no infrastructure to redirect floodwaters whatsoever. Around the world, floods kill thousands of people every year and are responsible for billions of dollars in damages and economic losses. 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
14833-550: The developing world, conflict over land rights due to the effects of globalization has led to less politically powerful groups, such as farmers, losing or forfeiting their land, resulting in obligatory migration into cities. In China, where land acquisition measures are forceful, there has been far more extensive and rapid urbanization (54%) than in India (36%), where peasants form militant groups (e.g. Naxalites ) to oppose such efforts. Obligatory and unplanned migration often results in
14996-587: The developing world, urbanization does not translate into a significant increase in life expectancy . Rapid urbanization has led to increased mortality from non-communicable diseases associated with lifestyle, including cancer and heart disease . Differences in mortality from contagious diseases vary depending on the particular disease and location. Urban health levels are on average better in comparison to rural areas. However, residents in poor urban areas such as slums and informal settlements suffer "disproportionately from disease, injury, premature death, and
15159-502: The developing world. 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. Grander schemes of damming and redirecting rivers should also be considered if possible. For saltwater coastal cities, desalination plants provide
15322-508: 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 prioritized, assigned inter-departmentally, and integrated into existing government policies and plans. The process is iterative and once resilience actions have been implemented, local governments monitor impact through
15485-460: The environment. Risk is the probability that exposure to a hazard will lead to a negative consequence, or more simply, a hazard poses no risk if there is no exposure to that hazard. Risk is a combination of hazard, exposure and vulnerability . For example in terms of water security : examples of hazards are droughts, floods and decline in water quality . Bad infrastructure and bad governance lead to high exposure to risk. Risk can be defined as
15648-431: 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 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 subsidized apartment buildings and in many cases have little to no contact with
15811-399: The equator, tending to be seasonal phenomena that are thus largely recurrent in time and predictable in location due to the specific climate variables necessary for their formation. The terms hazard and risk are often used interchangeably. However, in terms of risk assessment , these are two very distinct terms. A hazard is an agent that can cause harm or damage to humans, property, or
15974-426: 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 can 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
16137-422: The evolution of urban resilience 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 has moved urban planning academic discussions away from conventional approaches based in geometric plans to an approach informed by network science that involves less interference in
16300-509: The face of increased urbanization is at the centre of international policy in Sustainable Development Goal 11 "Sustainable cities and communities." Urbanization is not merely a modern phenomenon, but a rapid and historic transformation of human social roots on a global scale, whereby predominantly rural culture is being rapidly replaced by predominantly urban culture . The first major change in settlement patterns
16463-577: The face of multiple shocks and stresses, but also exploit opportunities for transformational development. One way that national and local governments address disaster risk in urban areas, often supported by international funding agencies, is to consider 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
16626-451: The first time in human history . Yale University in June 2016 published urbanization data from the time period 3700 BC to 2000 AD, the data was used to make a video showing the development of cities on the world during the time period. The origins and spread of urban centres around the world were also mapped by archaeologists . Urbanization occurs either organically or planned as
16789-574: 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. 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. Some research considered
16952-544: The flow motion. 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. 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. The deeper
17115-584: The food chain. Urbanization Urbanization (or urbanisation in British English ) is the population shift from rural to urban areas , the corresponding decrease in the proportion of people living in rural areas, and the ways in which societies adapt to this change. It can also mean population growth in urban areas instead of rural ones. It is predominantly the process by which towns and cities are formed and become larger as more people begin living and working in central areas. Although
17278-410: 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. This requires a better understanding of the types of practices and tools that contribute to building urban resilience. Genealogical approaches explore
17441-489: The growing population of urban regions, according to UN experts, will strain basic sanitation systems and health care, and potentially cause a humanitarian and environmental disaster. Urban heat islands have become a growing concern over the years. An urban heat island is formed when industrial areas absorb and retain heat. Much of the solar energy reaching rural areas is used to evaporate water from plants and soil. In cities, there are less vegetation and exposed soil. Most of
17604-433: 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
17767-442: The immediate needs of the most vulnerable citizens first. For post-flooding repair and reconstruction sufficient emergency funding should be set aside proactively. The United States The emergence of urban resilience as an educational topic in the USA has experienced an unprecedented level of growth due in large part to a series of natural disasters including the 2004 Indian Ocean earthquake and tsunami , 2005 Hurricane Katrina ,
17930-441: The impact that they have. In defining hazard Keith Smith argues that what may be defined as the hazard is only a hazard if there is the presence of humans to make it a hazard. In this regard, human sensitivity to environmental hazards is a combination of both physical exposure (natural and/or technological events at a location related to their statistical variability) and human vulnerability (about social and economic tolerance of
18093-611: The inconvenience of trips across them frequently combine to make marketplace competition harsher in cities than in rural areas. In many developing countries where economies are growing, the growth is often random and based on a small number of industries. Youths in these nations lack access to financial services and business advisory services, cannot get credit to start a business, and have no entrepreneurial skills. Therefore, they cannot seize opportunities in these industries. Making sure adolescents have access to excellent schools and infrastructure to work in such industries and improve schools
18256-414: The initial construction of infrastructure have in some cases even allowed urban economies to leapfrog stages of development. An unintended outcome of the growing digitization 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
18419-821: The links between social-ecological systems are being examined. Urban resilience is no longer the preservation of academics and urban policy groups around the globe are being put forward proposals to enhance the urban resilience of cities . The definition of urban resilience may vary, but is no longer limited to the speed at which an urban system recover after a shock. Academic discussion of urban resilience has focused primarily on three threats: climate change , natural disasters , and terrorism . 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
18582-441: 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
18745-693: The natural environment, and the built environment , particularly more vulnerable people, throughout history, and in some cases, on a day-to-day basis. According to the Red Cross , each year 130,000 people are killed, 90,000 are injured and 140 million are affected by unique events known as natural disasters. Potentially dangerous phenomena which are natural or predominantly natural (for example, exceptions are intentional floods ) can be classified in these categories: Natural hazards can be influenced by human actions in different ways and to varying degrees, e.g. land-use change, drainage and construction. Humans play
18908-504: The natural occurrence may become an event that presents a risk to the environment or people. For example, above-average wind speeds resulting in a tropical depression or hurricane according to intensity measures on the Saffir–Simpson scale will provide an extreme natural event that may be considered a hazard. Tsunamis can be caused by geophysical hazards, such as in the 2004 Indian Ocean earthquake and tsunami . Although generally
19071-443: 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
19234-426: The needs, opportunities and context of the city and evaluate the possibility of implementing the tool in their city. With local government partners, they 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
19397-417: The new industrial cities like Manchester and Birmingham which were experiencing a boom in commerce, trade, and industry. Growing trade around the world also allowed cereals to be imported from North America and refrigerated meat from Australasia and South America . Spatially, cities also expanded due to the development of public transport systems , which facilitated commutes of longer distances to
19560-739: The new Millennium Stadium and at the main Olympic site in Beijing, China . 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. 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
19723-565: The newly specialized residential areas of the bourgeoisie. The almost universal European division into a 'good' west end and a 'poor' east end of large cities developed in this period." This is probably caused by the south-west wind which carries coal smoke and other pollutants down, making the western edges of towns better than the eastern ones. Similar problems now affect less developed countries, as rapid development of cities makes inequality worse. The drive to grow quickly and be efficient can lead to less fair urban development. Think tanks such as
19886-469: The next 10 years. In the long term, urbanization is expected to significantly impact the quality of life in negative ways. Urbanization is relevant to a range of disciplines, including urban planning , geography , sociology , architecture , economics , education , statistics , and public health . The phenomenon has been closely linked to globalization , modernization , industrialization , marketization , administrative/institutional power , and
20049-500: The onset of the British Agricultural Revolution and Industrial Revolution in the late 18th century, this relationship was finally broken and an unprecedented growth in urban population took place over the course of the 19th century, both through continued migration from the countryside and due to the tremendous demographic expansion that occurred at that time. In England and Wales , the proportion of
20212-593: The opportunity to join, develop, and seek out social communities. Urbanization also creates opportunities for women that are not available in rural areas. This creates a gender-related transformation where women are engaged in paid employment and have access to education. This may cause fertility to decline. However, women are sometimes still at a disadvantage due to their unequal position in the labour market, their inability to secure assets independently from male relatives and exposure to violence. People in cities are more productive than in rural areas. An important question
20375-545: 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 digitized world. The urban impacts of climate change vary widely across geographical and developmental scales. A recent study 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
20538-642: 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. As part of their resilience strategies, city governments are increasingly relying on digital technology as part of
20701-409: The outside world. 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 are increasing each year. 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
20864-661: The overlapping and compounding risks from ethnicity or racial discrimination, gender, age, or disability, etc.)". Biological hazards, also known as biohazards, originate in biological processes of living organisms and pose threats to the health of humans, the security of property, or the environment. Biological hazards include pathogenic microorganisms , such as viruses and bacteria , epidemics , pandemics , parasites , pests , animal attacks , venomous animals , biological toxins and foodborne illnesses . For example, naturally occurring bacteria such as Escherichia coli and Salmonella are well known pathogens , and
21027-639: The place of older, less effective chemicals. Laws, such as the Federal Food, Drug, and Cosmetic Act and the Toxic Substances Control Act in the US, require protection of human health and the environment for any new chemical introduced. In the US, the EPA regulates new chemicals that may have environmental impacts (i.e., pesticides or chemicals released during a manufacturing process), while
21190-552: The planet",. However, existing infrastructure and city planning practices are not sustainable. In July 2013 a report issued by the United Nations Department of Economic and Social Affairs warned that with 2.4 billion more people by 2050, the amount of food produced will have to increase by 70%, straining food resources, especially in countries already facing food insecurity due to changing environmental conditions. The mix of changing environmental conditions and
21353-492: The population is increasing. Urbanization creates enormous social, economic and environmental challenges, which provide an opportunity for sustainability with the "potential to use resources much less or more efficiently, to create more sustainable land use and to protect the biodiversity of natural ecosystems." However, current urbanization trends have shown that massive urbanization has led to unsustainable ways of living. Developing urban resilience and urban sustainability in
21516-687: The population living in cities with more than 20,000 people jumped from 17% in 1801 to 54% in 1891. Moreover, and adopting a broader definition of urbanization, while the urbanized population in England and Wales represented 72% of the total in 1891, for other countries the figure was 37% in France , 41% in Prussia and 28% in the United States . As labourers were freed up from working the land due to higher agricultural productivity they converged on
21679-444: The possibility of failure associated with human technology (including emerging technologies ), which can also impact the economy , health and national security . For example, technological hazards can arise from the following events: A mechanical hazard is any hazard involving a machine or industrial process. Motor vehicles, aircraft, and air bags pose mechanical hazards. Compressed gases or liquids can also be considered
21842-690: The primary responsibility for follow-up and review of progress based on quality, accessible and timely data collection. National reviews influenced by regional progress will inform of the progress of the initiative globally. 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
22005-456: The probability of future loss whereby the degree of vulnerability to hazard represents the level of risk on a particular population or environment. The threats posed by a hazard are: Hazards can be classified in several ways. These categories are not mutually exclusive which means that one hazard can fall into several categories. For example, water pollution with toxic chemicals is an anthropogenic hazard as well as an environmental hazard. One of
22168-546: The rapid growth of slums. This is also similar to areas of violent conflict, where people are driven off their land due to violence. Cities offer a larger variety of services, including specialist services not found in rural areas. These services require workers, resulting in more numerous and varied job opportunities. Elderly people may be forced to move to cities where there are doctors and hospitals that can cater to their health needs. Varied and high-quality educational opportunities are another factor in urban migration, as well as
22331-515: The relative overall quality of life is very subjective, and may certainly surpass that of the city. Farm living has always been susceptible to unpredictable environmental conditions, and in times of drought , flood or pestilence, survival may become extremely problematic. – Iam Thongdee, Professor of Humanities, Mahidol University in Bangkok In a New York Times article concerning the acute migration away from farming in Thailand, life as
22494-412: The same location). An example of the distinction between a natural hazard and a disaster is that an earthquake is the hazard which caused the 1906 San Francisco earthquake disaster. A natural disaster is the highly harmful impact on a society or community following a natural hazard event. The term " disaster " itself is defined as follows: "Disasters are serious disruptions to the functioning of
22657-532: The same things cities offer, attracting the rural population and urban and suburban populations from other cities. Dominant conurbations are quite often disproportionately large cities , but do not have to be. For instance Greater Manila is a conurbation instead of a city. Its total population of 20 million (over 20% national population) make it a primate city, but Quezon City (2.7 million), the largest municipality in Greater Manila, and Manila (1.6 million),
22820-500: The same. A natural hazard is the threat of an event that will likely have a negative impact. A natural disaster is the negative impact following an actual occurrence of natural hazard in the event that it significantly harms a community. Disaster can take various forms, including hurricane, volcano , tsunami, earthquake, drought , famine , plague , disease, rail crash , car crash , tornado , deforestation , flooding, toxic release, and spills ( oil , chemicals ). A disaster hazard
22983-418: The severity of the associated risk varies. A hazard is defined as "the potential occurrence of a natural or human-induced physical event or trend that may cause loss of life, injury, or other health impacts, as well as damage and loss to property, infrastructure , livelihoods, service provision, ecosystems and environmental resources." A hazard only exists if there is a pathway to exposure. As an example,
23146-517: The skin. The negative effects of other chemicals, such as alcohol and nicotine , have been well documented. Organohalogens are a family of synthetic organic molecules which all contain atoms of one of the halogens . Such materials include PCBs , Dioxins , DDT , Freon and many others. Although considered harmless when first produced, many of these compounds are now known to have profound physiological effects on many organisms including man. Many are also fat soluble and become concentrated through
23309-489: 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
23472-518: The source is trade or tourism, it is also through the ports or banking systems, commonly located in cities, that foreign money flows into a country. Many people move into cities for economic opportunities, but this does not fully explain the very high recent urbanization rates in places like China and India. Rural flight is a contributing factor to urbanization. In rural areas, often on small family farms or collective farms in villages, it has historically been difficult to access manufactured goods, though
23635-652: The sun's energy is instead absorbed by buildings and asphalt; leading to higher surface temperatures. Vehicles, factories, and heating and cooling units in factories and homes release even more heat. As a result, cities are often 1 to 3 °C (1.8 to 5.4 °F) warmer than other areas near them. Urban heat islands also make the soil drier and absorb less carbon dioxide from emissions. A Qatar University study found that land-surface temperatures in Doha increased annually by 0.65 °C from 2002 to 2013 and 2023. Urban runoff , polluted water created by rainfall on impervious surfaces,
23798-469: 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
23961-464: The surrounding of habitat is, the fewer species can reach the habitat. Other times, such as with birds, urbanization may allow for an increase in richness when organisms are able to adapt to the new environment. This can be seen in species that may find food while scavenging developed areas or vegetation that has been added after urbanization has occurred i.e. planted trees in city areas – Jack Finegan, Urban Programme Specialist at UN-Habitat In
24124-470: The third leading cause of the release of methane, causing a concern on its impact to our ozone and on the health of individuals. Accumulation of food waste causes increased fermentation, which increases the risk of rodent and bug migration. An increase in migration of disease vectors creates greater potential of disease spreading to humans. Waste management systems vary on all scales from global to local and can also be influenced by lifestyle. Waste management
24287-805: The tool, which re-calibrates 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
24450-479: 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 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
24613-402: The towns where economic activity consisted primarily of trade at markets and manufactures on a small scale. Due to the primitive and relatively stagnant state of agriculture throughout this period, the ratio of rural to urban population remained at a fixed equilibrium. However, a significant increase in the percentage of the global urban population can be traced in the 1st millennium BCE. With
24776-539: The trend for core cities in said nations tends to continue to become ever denser. Development of cities is often viewed negatively, but there are positives in cutting down on transport costs, creating new job opportunities, providing education and housing, and transportation. Living in cities permits individuals and families to make use of their closeness to workplaces and diversity. While cities have more varied markets and goods than rural areas, facility congestion, domination of one group, high overhead and rental costs, and
24939-438: The two concepts are sometimes used interchangeably, urbanization should be distinguished from urban growth . Urbanization refers to the proportion of the total national population living in areas classified as urban, whereas urban growth strictly refers to the absolute number of people living in those areas. It is predicted that by 2050 about 64% of the developing world and 86% of the developed world will be urbanized. This
25102-418: 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, and this is not just in line with increased population densities, but is due to social factors and
25265-566: The utilization of innovative porous paving materials on city streets and car parks allow for the absorption and filtration of excess water. 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. The field deployment in an inundated street of
25428-574: 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
25591-524: The waste disposal industry, those living around sites used for waste disposal or landfill and the general environment surrounding such sites. There are different ways to group hazards by origin. The definition by UNDRR states: "Hazards may be natural, anthropogenic or socionatural in origin." The socionatural hazards are those that are "associated with a combination of natural and anthropogenic factors, including environmental degradation and climate change ". The term climate hazard or climatic hazard
25754-407: The well being 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
25917-425: 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. These factors, combined with the heat generated from vehicles, air conditioners and industry ensure that cities create, absorb and hold heat very effectively. The physical causes of heat waves and droughts and the exacerbation of the UHI effect are only part of
26080-523: 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 or make them floating or considerations should be made to relocate or rebuild structures on higher ground. A house in Mexico Beach, Florida which survived Hurricane Michael
26243-474: Was also disastrous, with nearly 5,000 deaths occurring in Moscow. 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 . Agricultural losses from heat and drought might not occur directly within
26406-570: Was not a primary concern until after the Industrial Revolution. As urban areas continued to grow along with the human population, proper management of solid waste became an apparent concern. To address these concerns, local governments sought solutions with the lowest economic impacts which meant implementing technical solutions at the very last stage of the process. Current waste management reflects these economically motivated solutions, such as incineration or unregulated landfills. Yet,
26569-449: Was the accumulation of hunter-gatherers into villages many thousands of years ago. Village culture is characterized by common bloodlines, intimate relationships, and communal behaviour, whereas urban culture is characterized by distant bloodlines, unfamiliar relations, and competitive behaviour. This unprecedented movement of people is forecast to continue and intensify during the next few decades, mushrooming cities to sizes unthinkable only
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