With the world's cities never having been so at risk of disruption by disasters as they are now, Secretary-General Ban Ki-moon Wednesday underscored the need for wide participation in bolstering the resilience of urban areas to hazards.

Words such as "biggest, deadliest, [and] worst ever" have been prevalent in headlines this year on earthquakes, floods, hurricanes and other disasters, Mr. Ban said in his message on the International Day for Disaster Reduction.

"Those words are likely to be heard for years to come, as the climate changes and hazards multiply," he added.

According to figures cited by the United Nations International Strategy for Disaster Reduction (ISDR), more than 236,000 people have been killed by disasters, with more than 250 million others affected by earthquakes, floods, tropical storms and landslides.

Changes in weather patterns have coincided with shifts in human society, as more than half of the world's population now lives in cities. "If earthquakes, floods or storm surges were deadly in the past, they are deadlier still in an increasingly urbanized world," the Secretary-General stressed.

He pointed out that many of the world's cities lie along coasts, making them vulnerable to storms, inundation and sea level rise. More than one billion people in Asia live within 100 kilometres of the coast, while two-thirds of the population of the Latin America and the Caribbean reside within 200 kilometres of the sea.

With many living on flood plains, above earthquake fault lines or downstream from treeless areas, "the risk of disaster quietly accumulates," making the poorest people most vulnerable, Mr. Ban noted.

"On the positive side, we are learning to cope," he said, with the International Day providing an opportunity to recognize the efforts made by local governments and communities to protect themselves while simultaneously building more sustainable towns and cities.

"Reducing disaster risk is everybody's business, and needs everyone's participation and investment – civil society, professional networks as well as municipal and national governments," the Secretary-General said, commending those cities that are acting to bolster their resilience to disaster.

This year's Day comes as the ISDR's campaign to bolster cities' resilience against natural hazards is well under way, with more than 100 cities – home to more than 100 million people – having signed on.

The two-year Making Cities Resilient: My City is Getting Ready scheme focuses on a checklist of so-called Ten Essentials, including reinforcing drainage systems to reduce the likelihood of floods, installing early warning systems and carrying out public preparedness drills to make communities safer from disasters.

Marking the Day, Margareta Wahlstr?m, the Secretary-General's Special Representative for Disaster Risk Reduction, called on world leaders, policy-makers, corporate titans, civil society, international financial institutions and donors to join the world's mayors and citizens make their cities safer against disasters.

"Today's urban planning demands foresight and much more attention to disaster risk," she emphasized, noting that poorly-built buildings on floodplains, above quake faults and along fragile slopes expose millions to disasters.

According to the UN Human Settlements Programme (UN-HABITAT), more than one billion people currently reside in slums and are particularly at risk of hazards.

By 2030, it is predicted that this figure will double and that 60 per cent of the world's population will live in urban areas.

"We cannot stop cities growing but we can start planning them in a more sustainable way," Ms. Wahlstr?m said. "It does not require huge amounts of new resources, but different ways of using existing resources. It requires better coordination between all actors and use of good practices that have already been tested."

ISDR pointed out that poor regulations in shanty towns compounded the catastrophic January earthquake in Haiti, where one in every 15 people affected was killed in the disaster.

In comparison, the magnitude of the February quake in Chile was 500 times less than that of the one in Haiti, but only claimed the lives of one out of every 595 affected.

Disasters this year also damaged hundreds of hospitals and clinics, underscoring the threats faced by health services in urban areas and the need to ensure that these facilities can continue providing much needed care during emergencies, according to the UN World Health Organization (WHO).

"Hospitals, clinics and other health facilities are the foundation of any health response to be launched to save the lives of people injured when their city is struck by a disaster," said Eric Laroche, WHO's Assistant Director-General for Health Action in Crises.

"But we see to often that when disasters happen, health facilities and the staff who work in them count among the casualties."

To protect these sites, WHO recommends that new hospitals be located in safe areas not prone to disasters and that they be built in compliance with building standards. The agency also underlines the importance of emergency preparedness programmes and the development of response plans.

For its part, the UN Children's Fund (UNICEF) spotlighted the need to step up efforts to mitigate the impacts of disasters on children, who typically represent up to 60 per cent of those affected by disasters, be it through death or diseases related to malnutrition and poor water.

Further, the agency warned, disasters disrupt education and can cause psychological distress. They can also lead to child exploitation.

UNICEF urged education, public awareness, community-based preparedness, life skills and the erection of disaster-resilient buildings as ways to curb disaster risk for children.

Events to commemorate the Day are being held around the world. In Shanghai, a panel discussion drawing experts, including a television reporter who covered the deadly Sichuan earthquake of 2008, will be held, while in Syria, the Making Cities Resilient campaign will be launched.

In the Asia-Pacific, a drawing competition to commemorate the Day was held.

"Disaster risk reduction is about saving people's lives," stressed Noeleen Heyzer, Executive Secretary of the UN Economic and Social Commission for Asia and the Pacific (ESCAP), which helped to organize the event, together with ISDR, Thailand's Interior Ministry and the Association of South-East Asian Nations (ASEAN).