Adrian Lahoud, UTS Senior Lecturer, Course Director of Master of Advanced Architecture in Urban Design, writes for The Conversation:

We are entering an era of massive population transfer – a rural exodus of unprecedented proportions. In Asia and Africa farmers and peasants are being lured to mega-cities. This brings myriad benefits in terms of transport and energy use, but it also brings new forms of risk. Shenzhen in China and Lagos in Nigeria are swelling to gargantuan size. But even a city as large as Shenzhen is easily swallowed by the megalopolis now forming between Macau, Guangzhou and Hong Kong. A UN Habitat report from 2010 estimated over 120 million people living in this region alone. This enormous population pressure can be dangerous.

Two events expose these risks; the SARS outbreak in 2002 and the recent earthquake and tsunami in Japan. As population centres creep closer to rural areas and expand around fault lines or flood zones, the death toll from traumatic events can rise exponentially. The catastrophe in Japan could have been significantly worse, had it not been for some important measures; such as a sophisticated tsunami warning system and a strict building code.

Though we like to think the reason for a low death toll during the recent floods and cyclones in Australia had something to do with our plucky national character or Queensland Premier Anna Bligh’s political virtuosity, these had very little real impact. The death toll was low because very few people live here.Australia is the second most sparsely populated continent on earth – more populated than Antarctica and one fifth as dense as South America.

On the other hand, countries with high population densities and without the benefits of first world membership such as Haiti or Bangladesh are savaged by natural disasters in even more catastrophic ways. The combination of urban density, poor infrastructure, poor governance and poverty is deadly. The death toll from the 7.0 magnitude quake in Haiti last year now stands at a staggering 300,000. The tragic but eventual intersection of urbanization, natural disaster and epidemic will cause these figures to balloon further.

The strategic challenges facing city-making are significant. Do we abandon the poor to live in high-risk areas? How do we support industrial growth and urbanization in developing countries? What about migrant workers and refugees – do we open our cities to them or close the gates behind us? ………

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Launched in March 2011, The Conversation is an independent source of information, analysis and commentary from the university and research sector.