Poverty, gender, class, caste and ethnicity are powerful influences on urban vulnerability, just as they are in rural areas. Poor and marginalised people are more likely to live in poor-quality housing, in neighbourhoods without adequate infrastructure (clean water, drains, paved roads, power supplies and health facilities), and where sanitation systems, garbage collection and public health services are inadequate. This makes them vulnerable to a variety of environmental hazards. High housing and population densities also magnify the effects of pollution and disease.
Poverty forces many people to live in the most polluted and dangerous areas: steep-sided valleys, floodplains and hillsides, and next to roads, waste dumps and hazardous industries. Where they lack legal title to their property – as in many low-income urban settlements – and live in fear of eviction, they have little incentive to invest in private or communal mitigation measures, and in any case have little money for doing so. Landlords are often unwilling to invest in their properties, and may raise the rents of properties improved by their tenants. Local governments may refuse to provide services to informal settlements on the grounds that this will imply recognition of people’s right to the land they have settled on.
Domestic fires, which are a significant risk in houses made of materials that burn easily, such as wood, thatch and cardboard, can, where homes are packed tightly together, easily get out of control. Urban spaces with irregular layouts and narrow streets, crowded with buildings (including high-rise), waste and vehicles and densely populated, can present particular challenges to service provision (such as water supply and waste removal) as well as to emergency response, evacuation and rescue (as in Port-au-Prince, Haiti, after the 2010 earthquake). Industrial accidents can be devastating in populous urban settings. One of the most well-known, the explosion at a chemical factory in the Indian city of Bhopal in 1984, resulted in around 5,000 deaths in the following days, with many more subsequently; around 60,000 people required long-term treatment.+R. Varma and D. R. Varma, ‘The Bhopal Disaster of 1984’, Bulletin of Science, Technology and Society, 25 (1).
Uncontrolled urban development damages the environment and increases risk. Deforestation, land clearance and subsequent construction may expose hillsides, making them more vulnerable to landslides. Natural drainage is impeded when floodplains are built upon. Unregulated construction leads to unsafe buildings, and here it is not only the poor who are vulnerable: many of the fatalities in earthquakes have been in badly built middle-class apartment blocks. Poor land use planning may lead to critical infrastructure such as hospitals, electricity sub-stations and water treatment plants being built in high-risk locations. It may also increase risks, for example by permitting construction that blocks natural drainage systems, leading to increased flooding.
Urban life has a profound impact on livelihoods and coping strategies. Town-dwellers rely on cash income from their labour to a much greater extent than people who live in the countryside. Livelihood strategies are therefore heavily based on finding paid work (which can also be an advantage if households have several different sources of income and do not depend on a single economic activity). The poor are also more likely to undertake dangerous work such as scavenging on unstable rubbish dumps or labouring in industries where working practices are unsafe, such as garment making and construction.
Social cohesion and social capital in the form of community organisations and support networks may be weak in new urban communities, especially ones that comprise many different social groups, where there are no extended family structures or where people are frequently moving in and out of rented accommodation. Newcomers are likely to lack experience and understanding of specifically urban hazards and avoidance strategies. Many towns and cities have large populations of refugees or internally displaced people who may be particularly marginalised, neglected or discouraged by municipal authorities and other aid and development agencies, and whose presence is sometimes resented by established residents.+S. Haysom, Sanctuary in the City? Urban Displacement and Vulnerability (London: Overseas Development Institute, 2013), http://www.odi.org.uk/hpg. Camps for refugees and internally displaced people, originally planned as short-term emergency settlements, assume semi-permanent status, becoming in effect new towns.
Dependence on public services and structures (e.g. power, water supplies, public transport infrastructure and emergency services) and external food supplies is much greater in urban areas. Hazard events can cause severe damage to critical infrastructure such as power supplies and transport systems, even in large and wealthy cities, as in the case of Hurricane Sandy in New York in 2012. Politicians and officials have to be lobbied to make improvements to services, although the poor tend to have the least political influence here. City and municipal authorities often lack the financial resources and political will to control pollution, provide adequate infrastructure and services, make suitable land available to poor people and implement large-scale mitigation measures.
Risk and vulnerability assessments are carried out frequently in towns and cities as part of DRR planning, just as they are in rural areas, often using similar assessment approaches and tools. In recent years, more thought has been given to developing approaches specifically for urban contexts, for example by including infrastructure and urban services in addition to the areas covered by conventional assessments. There are many examples of such approaches and methods, developed for different agencies and types of intervention; recent examples include:
The rapid pace of urban expansion and development, together with the growth and mobility of populations and the existence of large informal settlements, make it very difficult to collect accurate, comprehensive information and keep it up to date.