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How does a changing climate impact on urban poverty?

9 April 2013

When floods hit a city, it is usually low-income groups that are hit hardest. The devastation that such disasters cause can be linked to the failure of city governments to manage growth, build infrastructure and work with low-income groups.


Floods are among the most common causes of disasters in cities. Many cities are built on rivers or on low-elevation sites on coasts so they’re vulnerable to flooding. As cities expand, so the increased building further limits natural drainage and can increase flood risks each time it rains heavily.

In the last year, the list of cities where serious floods and loss of life has occurred include Jakarta, Chittagong, Manila, Beijing, Krymsk, Buenos Aires, various cities in Nigeria, New York and other cities in the US, and the Caribbean which was hit by hurricane Sandy in October 2012. In 2011 floods in Thailand devastated Bangkok and many other Thai cities (and rural areas).

In this year, serious floods hit many cities in Cambodia, Vietnam, Laos, the Philippines, Myanmar, Pakistan and China. Many more cities would be added to this list if reports on flooding were more detailed and comprehensive. Many floods do not get reported, or reports of flooding only refer only to the region in which the flooding occurred, not the locations most affected.

Most cities are at increasing risk from the effects of climate change, including increasing heat waves and, for coastal cities, rising sea levels and storm surges. In many locations, climate change is also likely to be increasing the intensity of extreme rainfall in the city or ‘upstream’, as seen in Bangkok in 2011. Climate change is likely to constantly increase these risks; the world is still so far away from reaching agreement on the measures needed to halt global warming.

Around one in seven of the world’s population lives in informal settlements in urban areas. When storms or floods hit cities, it is generally low-income groups that are hit hardest in terms of deaths and injuries. This is especially true when they live in informal settlements found in most cities in Africa, Asia and Latin America.

The devastation caused by storms and flooding to cities cannot be attributed to climate change. A city government’s ability or failure to manage city growth, to ensure that risk-reducing infrastructure is in place and that low-income groups can find shelter on safe sites, is key. Having early warning systems in place when storms approach, and measures to ensure those most at risk can and do move to safer locations when needed is also critical.

And people are starting to make this connection. Somsook Boonyabancha’s blog highlights how excess water management became a sensitive political matter in Thailand during the unprecedented flooding in 2011 and led to confusion and delays in the government’s response.

Most informal settlements lack risk-reducing infrastructure, such as functioning storm drains. Most cities in sub-Saharan Africa and many in Asia have no sewers and storm drains – or if they do, these only serve a small proportion of their population and certainly not those living in informal settlements. Most houses in informal settlements are poorly built, and more liable to collapse when hit by storms or floods. Many informal settlements develop on dangerous sites – for instance flood plains or unstable slopes – because housing on safer sites is too expensive for them. It is also very rare for people living in informal settlements to have insurance for their homes, health or possessions – and no business will insure someone who faces very high risks and has very limited capacities to pay.

Self-help measures

Of course, low-income households take measures to try to reduce risks. To protect against flooding, they may build homes on stilts or walls around doorways to stop floodwaters entering their homes. They may dig ditches to divert flood waters away from their home. In settlements that often flood, people put shelves up as high up as possible (to store food and water safely). Cupboards or tables can be sat at or slept on when the house is flooded (and their height may be increased – for instance by standing them on bricks). Read Luiz Inácio Lula da Silva (former President of Brazil) describing how his home in Sao Paulo was constantly flooded, and what they did to cope.

But these are self-help measures, aimed at survival and at limiting the damage done. Residents in informal settlements need the basic infrastructure that should serve all homes and neighbourhoods – water piped to the home, sewers or other means to remove human wastes, storm and surface drains and regular collection of household wastes (also essential for keeping drains clear). Also all-weather roads and paths would allow residents to move away from rising flood waters and allow access to emergency vehicles. Without such improvements residents face ever increasing risks posed by disasters.

Why so little action?

What will it take to get city governments to act on this and to get national governments to support them in doing so? When will this grab the attention of international agencies, most of whom have given little or no attention to these issues or to cities?

In cities in high-income nations, low-income groups also face many disadvantages, but the vast majority at least live in homes that do not collapse during storms or floods and in settlements with basic infrastructure.

But city governments can take measures to reduce urban poverty that also contribute to reducing disaster risk and to building greater resilience to climate change. For example, they can support low-income households to buy or build safer homes or work with them to identify safer sites to move to.

Addressing the massive backlog in basic infrastructure is often best done in partnership with community-organizations as this lowers costs and speeds implementation. Having a city government that sees the necessity of working with the inhabitants of informal settlements – and working with their organizations – is crucial. Many cities have federations or networks of grassroots organizations formed by slum/shack dwellers that are working in partnership with local governments to address disaster risks (as documented in the Philippines). The Asian Coalition for Community Action is rethinking how external funding can support low-income communities to work together to reduce risk.

As the basic infrastructure that all city districts need is built or improved, so this builds the financial and institutional basis for greater resilience to the impacts of climate change.

Find out more

Read Environment and Urbanization Brief 23 on how support for community organizations, including those formed by disaster survivors, can achieve effective post-disaster responses and, in the longer term, effective responses to disaster risk reduction and climate change adaptation.

David Satterthwaite

IIED, 28/3/2013