The cracks beneath the surface

Suffering the highest rates of natural disasters of any region in the world, Asia has been ravaged by earthquakes, floods, volcanic eruptions and tsunamis, causing billions of dollars in damage and costing the lives of millions. In this special report, Asia Infrastructure takes a look at why the region is so vulnerable to the effects of earthquakes, and what can be done to help prevent the human and financial costs.

On Monday October 25th, an earthquake off the coast of Sumatra, Indonesia, caused a tsunami to hit the coastal towns and villages, destroying hundreds of homes and killing an estimated 400 people. Across the water, on Jakarta, Mt. Merapi volcano began erupting, killing 36 people and causing some 75,000 to be evacuated from their homes in the surrounding area. A week later, on November 3rd, the volcano erupted again, this time with more force, bringing the death toll over 100 and doubling the number of people forced to evacuate their homes.

These recent events in Indonesia are just the latest natural disasters to destroy the homes, villages and towns of the Asia's people. Since 1900, Asia has experienced 611 earthquakes and tsunamis, killing a total of 1,796,928 people and affecting the lives of a further 27,251,849, with recovery costs reaching an estimated US$320 billion. These figures are more than double those of the Americas region, the next region most severely affected by natural disasters in the world.

A recent report from the United Nations and the World Bank entitled 'Natural Hazards, UnNatural Disasters' estimates that by 2100 global losses from natural disasters could reach US$185 billion a year, three times the rate they are now. This figure does not take into account climate change. And with Asia accounting for the overwhelming majority of disasters, such figures represent a significant cost for these developing economies. UN's special representative on disaster risk reduction Margareta Wahlstrom, speaking to a group of Asian parliamentarians at a meeting in Manila, Philippines, in November, recommended that the region's governments should allocate at least one percent of national budgets toward disaster risk reductions strategies, and explained that such projects would contribute to reducing poverty in developing nations by protecting people's assets.

Indeed, poverty in developing economies is a significant factor contributing to the death toll and structural damage caused by natural disaster. Make-shift developments, slums and shanty-towns in compact areas of urban environments, built without any cohesive regulation and standards are highly vulnerable to the damages caused by a earthquakes and floods. Similarly, the rapid population booms in Asian cities has resulted in wide-scale mass development of buildings without proper regulation or a holistic approach to infrastructure. According to the UN's statistics, a number of cities in areas of the developing world - Latin America, Africa and Asia - have doubled their size in less than 30 years, and by 2015 12 of the top 15 cities in the world in terms of size will be in the developing world, with much of the urban expansion taking place outside the official and legal frameworks of building codes and land use regulations.

And combined with high population densities and unsustainable urbanised areas, the Asia region experiences the highest levels of seismic activity in the world, exacerbating its weak infrastructure. Of the eight most populous cities that sit on an earthquake faultline, six of them are in Asia - Tokyo, Mumbai, Delhi, Shanghai, Kolkata and Jakarta. Similarly, of the top 10 most populous cities in the world exposed to costal flood hazard, again six are in the Asia region - Mumbai and Kolkata, Guangzhou and Shanghai, Ho Chi Minh City and Osaka-Kobe.

Buildings

A paper published as part of the UN's 'Making Cities Resilient' campaign highlighted that "Sustainable urbanisation requires comprehensive steps to enforce urban planning regulations and building codes." The paper made some estimates as to the losses likely to be sustained if an earthquake were to occur in Asia's megacities. For example Mumbai, which has been cited as having an extremely vulnerable building stock, is an urban environment with a wide variety of constructions; the paper estimates that a moderate earthquake in the city could result in a death toll of 34,000 people.

Significantly, available data indicates that up to 80 percent of deaths from natural disasters occur in the buildings that collapse during earthquakes. In the Sichuan earthquake in China back in 2008 that killed at estimated 68,000 people, at least eight schools were flattened in the tremors. Of the total death toll, an estimated 12 percent were schoolchildren and their teachers, a fact many have attributed to the poor building standards of the schools themselves. In the Beichuan county region of Sichuan province around 80 percent of the buildings were destroyed; across the whole affected area at least five million people were left without housing, although subsequent research estimated the actual figure could have been double that number.            

Damage caused by the earthquake was exacerbated by the poor standards of constructions in the region. The Chinese government implemented building regulations thought to be as stringent as those in the West after the devastating quake of 1976 in Tangshan that killed over 40,000 people. However, many of the buildings affected by the Sichuan quake - and indeed, a great number of buildings across China as a whole - were built before these regulations came into effect. In addition to this, investigations following the 2008 disaster indicated that in a great many cases the building codes were not properly adhered to.

Indeed, a World Housing Encyclopaedia Report published in 2002 indicated an increasing use of multi-storey base isolated brick masonry building with reinforced concrete floors and roof over the preceding 25 years. The report found that the rubber isolation systems of such constructions were between 4 and 12 times stronger against seismic activity than non-isolated brick masonry buildings. However although these buildings withstood the effects of earthquakes well, they are currently to be found mainly in urban areas. Many reports suggested that though the engineering technology was available to Chinese developers, and was commonly practiced in wealthier, urbanised areas, it was not commonly used in rural areas.

Similarly Indonesia, a nation of high population density but less economically developed than China, had no building legislation in place until 2002, and the law passed at that time had been originally drafted as far back as 1964. Local authorities put regulations in place regarding building development before the 2002 law was passed, however in reality compliance with these regulations rested in the hands of the architects, engineers and contractors involved in a particular project. The World Housing Encyclopaedia reported on the wide spread use of unreinforced clay brick masonry housing in Indonesia, often found in rural areas, which have a low resistance to the lateral pressure of seismic activity. Indonesia suffers some of the highest rates of natural disasters of any country in the world due to its geology, and vulnerable buildings contribute to a significant proportion of deaths each year.

Still, despite evidence that the poorest people are the hardest hit by natural disasters, Asia's most economically developed countries and regions still lack the comprehensive disaster engineering found. Japan, Asia's most affluent nation in terms of per capita GDP, had a series of regulations implemented in the early 1960s, and while most buildings adhered to these standards, they were proved in the 1980s to be highly insufficient to protecting the buildings against the effects of natural disasters. Still, buildings that had implemented these standards remained in place, leaving them extremely vulnerable to the effects of the seismic activity, a fact highlighted by the damage caused by the 1995 earthquake in Kobe. Though the death toll and building damage sustained was considerably less than that suffered in China in 2008, compared to a similar event in the West the figures represented significant shortcomings in the engineering standard of Japan's infrastructure.

An earthquake in Los Angeles in 1994, with an immediate population base of roughly the same as the Kobe quake (around two million) and an intensity level of 6.6 compared to Kobe's 7.2, left a death toll of only 72 while the figure in Kobe was over 6000. As in China, many of the buildings affected were unreinforced masonry constructions, which simply collapsed under the seismic pressure of the earthquake.

Flood relief

While poorly regulated building standards are undoubtedly the most pressing challenge facing Asian governments, developers and engineers in terms of protecting against the effects of natural disasters, the implementation of comprehensive municipal infrastructure is another issue contributing to the damage caused by earthquakes and floods. The UN's paper cited Kathmandu as an example of a city in which poorly developed urban infrastructure created additional hazards to increasing the effects of natural disasters. Like so many Asian metropolises, the Nepalese capital had experienced a massive increase in population that strained public authorities' ability to provide services. In addition to the buildings' incapacity to withstand an earthquake, a lack of water infrastructure, unsafe electrical installation and roads too narrow for emergency vehicles to move down have all been identified as factors exacerbating the damage of a natural disasters, which could easily be preventable with the correct infrastructure.

And if the current climate change trend continues, Asian coastal cities will flood more often. According to a report carried out by the World Bank indicated that the cities vulnerable to such events, notably Bangkok, Ho Chi Minh and Manila are likely to sustain billions of dollars worth of damage as a result of flooding. And flood damage is exacerbated by the cities' urban environmental management, with drainage systems blocked, waste left in canals and waterways and deforestation of upper watershed areas.

Ultimately, the effects of the changing world such as increased extreme weather events and a greater prevalence of seismic activity are factors beyond the control of the urban planners. However, comprehensive and resilient earthquake engineering in communities, both urban and rural, and a strategic infrastructure system equipped to provide relief can be implemented into the living environments of Asia's communities. The UN defines a disaster resilient city as one in which homes and neighbourhoods served by piped water, comprehensive sanitation and drainage systems, all-weather roads and secure electricity, as well as public services such as healthcare and schools, emergency services and garbage collections, in structures that meet appropriate building codes, and without the need to settle on vulnerable terrains in informal constructions.

The report also highlighted that disaster preparation should be a subjective strategy, based on a risk assessment prepared for an individual city and used as a planning tool when developing any project in an urban environment. Additionally, investment in critical infrastructure that reduces risk, such as strategic flood drainage, should take place. Similarly, comprehensive but realistic building regulations and standards, such as China's based reinforced masonry buildings, should be introduced and adhered to.

Case study: Great Hanshin earthquake, Kobe, Japan

On the 17th January 1995, a 7.3 magnitude (JMA scale) earthquake hit the southern area of Hyogo Prefecture in Japan, lasting around 20 seconds. The epicentre of the quake was roughly 20 kilometres away from Kobe. The total death toll was estimated at 6,434 and the quake caused a reported US$102.5 billion worth of damage.

Construction materials such as the traditional heavy roof tiles commonly found in Japan and the light wood used in the support frames combined with factors such as the lack of reinforcement in most buildings added to some 20 percent of houses in certain areas of the city being completely destroyed. In the central business district, 22 percent of the offices and 50 percent of the houses were rendered unfit to live in.

The elevated Hanshin Expressway was among the worst hit of the region's infrastructure, with road-blocks in three locations and half the piers were damaged in some way. Daikai Station, on the Kobe Rapid Railway completely collapsed. Investigations in the aftermath of the quake indicated that most collapsed constructions had been built to outdated safety regulations, outlined in the 1960s and long known to inadequate and in need to revising.