More than half of the world’s population lives in towns and cities. About two-thirds of the current urban population live in low- and middle-income nations in Africa, Asia, Latin America and the Caribbean. The DRR issues and themes discussed elsewhere in this book apply equally to urban settings; but, at the same time, managing urban risks presents its own challenges. If managed well, growth and urbanisation bring many economic and social benefits to towns and cities and the people who live and work in them. Cities and towns generate wealth and provide jobs, for example. It is also more straightforward to provide basic needs and social and cultural services where large numbers of people live closely together. However, achieving such gains depends on the context in which urbanisation takes place and how the process is managed. Poverty and poor urban management mean that many cities are expanding in an uncontrolled way. This has led to severe social, economic and environmental problems. It is also putting greater numbers of people at risk from natural and technological hazards.
Urban populations in high-income nations tend to be well protected by government institutions and regulations, together with robust infrastructure and effective services (although these can fail: the Hurricane Katrina disaster in New Orleans in 2005 is a good example). However, many inhabitants of towns and cities in low- and middle-income countries lack good-quality infrastructure and services, such as water and sanitation, drainage, roads, healthcare and emergency services. Perhaps as many as a billion people worldwide live in informal settlements (or slums), with poor living conditions; their incomes and access to employment opportunities may be limited and insecure.