Vietnam’s typhoon disaster highlights the plight of its poorest people


Chinh Luu, University of Newcastle and Jason von Meding, University of Newcastle

Six people lost their lives when Typhoon Doksuri smashed into central Vietnam on September 16, the most powerful storm in a decade to hit the country.

Although widespread evacuations prevented a higher death toll, the impact on the region’s most vulnerable people will be extensive and lasting.


Read more: Typhoon Haiyan: a perfect storm of corruption and neglect.


Government sources report that more than 193,000 properties have been damaged, including 11,000 that were flooded. The storm also caused widespread damage to farmland, roads, and water and electricity infrastructure. Quang Binh and Ha Tinh provinces bore the brunt of the damage.

Central Vietnam is often in the path of tropical storms and depressions that form in the East Sea, which can intensify to form tropical cyclones known as typhoons (the Pacific equivalent of an Atlantic hurricane).

Typhoon Doksuri developed and tracked exactly as forecast, meaning that evacuations were relatively effective in saving lives. What’s more, the storm moved quickly over the affected area, delivering only 200-300 mm of rainfall and sparing the region the severe flooding now being experienced in Thailand.

Doksuri is just one of a spate of severe tropical cyclones that have formed in recent weeks, in both the Pacific and Atlantic regions. Hurricanes Harvey, Irma and, most recently, Maria have attracted global media coverage, much of it focused on rarely considered angles such as urban planning, poverty, poor development, politics, the media coverage of disasters – as well as the perennial question of climate change.

Disasters are finally being talked about as part of a discourse of systemic oppression – and this is a great step forward.

Vietnam’s vulnerability

In Vietnam, the root causes of disasters exist below the surface. The focus remains on the natural hazards that trigger disasters, rather than on the vulnerable conditions in which many people are forced to live.

Unfortunately, the limited national disaster data in Vietnam does not allow an extensive analysis of risk. Our research in central Vietnam is working towards filling this gap and the development of more comprehensive flood mitigation measures.

Central Vietnam has a long and exposed coastline. It consists of 14 coastal provinces and five provinces in the Central Highlands. The Truong Son mountain range rises to the west and the plains that stretch to the coast are fragmented and narrow. River systems are dense, short and steep, with rapid flows.

These physical characteristics often combine with widespread human vulnerability, to deadly effect. We can see this in the impact of Typhoon Doksuri, but also to a lesser extent in the region’s annual floods.

Flood risk map by province using Multi-Criteria Decision-Making method and the national disaster database.
Author provided

Rapid population growth, industrial development and agricultural expansion have all increased flood risk, especially in Vietnam’s riverine and coastal areas. Socially marginalised people often have to live in the most flood-prone places, sometimes as a result of forced displacement.

Floods and storms therefore have a disproportionately large effect on poorer communities. Most people in central Vietnam depend on their natural environment for their livelihood, and a disaster like Doksuri can bring lasting suffering to a region where 30-50% of people are already in poverty.

When disaster does strike, marginalised groups face even more difficulty because they typically lack access to public resources such as emergency relief and insurance.

The rural poor will be particularly vulnerable after this storm. Affected households have received limited financial support from the local government, and many will depend entirely on charity for their recovery.

Better research, less bureaucracy

This is not to say that Vietnam’s government did not mount a significant effect to prepare and respond to Typhoon Doksuri. But typically for Vietnam, where only the highest levels of government are trusted with important decisions, the response was bureaucratic and centralised.

This approach can overlook the input of qualified experts, and lead to decisions being taken without enough data about disaster risk.

Our research has generated a more detailed picture of disaster risk (focused on flood hazard) in the region. We have looked beyond historical loss statistics and collected data on hazards, exposure and vulnerability in Quang Nam province.

Left: flooding hazard map for Quang Nam province. Right: risk of flooding impacts on residents, calculated on the basis of flood hazards from the left map, plus people’s exposure and vulnerability.
Author provided

Our findings show that much more accurate, sensitive and targeted flood protection is possible. The challenge is to provide it on a much wider scale, particularly in poor regions of the world.

Reduce risk, and avoid creating new risk

An effective risk management approach can help to reduce the impacts of flooding in central Vietnam. Before a disaster ever materialises, we can work to reduce risk – and avoid activities that exacerbate it – for example land grabbing for development, displacing the poor, environmental degradation, discrimination against minorities.


Read more: Irma and Harvey: very different storms, but both affected by climate change.


It is critical that subject experts, particularly scientists, are involved in decisions about disaster risk – in Vietnam and around the world. There must be a shift to more proactive approaches, guided by deep knowledge both of the local context and of the latest scientific advances.

Our maps will help planners and politicians to recognise high-risk areas, prepare flood risk plans, and set priorities for both flood defences and responses to vulnerability. The maps are also valuable tools for communication.

The ConversationBut at the same time as emphasising data-driven decisions, we also need to advocate for a humanising approach in dealing with some of the most oppressed, marginalised, poor and disadvantaged members of the global community.

Chinh Luu, PhD candidate in Disaster Management, University of Newcastle and Jason von Meding, Senior Lecturer in Disaster Risk Reduction, University of Newcastle

This article was originally published on The Conversation. Read the original article.

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Grenfell Tower fire exposes the injustice of disasters


Jason von Meding, University of Newcastle; Giuseppe Forino, University of Newcastle; J.C. Gaillard, and Ksenia Chmutina, Loughborough University

Decades of gentrification in London and other European cities (including Paris, Barcelona, Rome and Istanbul) have enacted a form of social cleansing. This has pushed away low-income and marginal residents, divided the rich from the poor, and generated inequalities among citizens.

The Hammersmith area, where the Grenfell Tower is located, has been gentrified. This previously working-class area has been transformed into a vibrant middle-class neighbourhood. Just a few residential social housing tower blocks remain.

As a cosmetic measure, the Grenfell Tower was refurbished in 2014. The choice of cladding material that appeared to fuel the fire is now subject to scrutiny, but with no understanding of the social dimensions of the building’s design regulation and safety measures.

Repeated warnings from the Grenfell Tower residents that this was a disaster waiting to happen were ignored.


Grenfell Action Group

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There has been an outpouring of grief and anger from the affected community and beyond and tensions remain high. While certain elements of the media rebuke those seeking to hold the ruling class accountable, it is important to emphasise a simple truth: disasters are socially – and politically – constructed.

Root causes of disaster

Disasters are often misunderstood as “natural”, or simply assumed to be extreme and tragic events.

This view draws on a century-old paradigm that puts the blame on rare and inescapable natural phenomena, an “act of God”, or technological breakdowns that lie beyond the everyday social fabric.

But there is nothing natural about disasters; disasters usually have root causes of vulnerability that we don’t speak about and that reflect the day-to-day make-up of society – inequality, poverty, political ideology, class and power relations.

These root causes are similar in London, New York, New Orleans, Port-au-Prince and Manila – a few of the world’s cities that have been stricken by major disasters in recent times.

The Grenfell Action Group couldn’t have been clearer in its warnings of disaster – this one is from November 2016.
Grenfell Action Group

Disasters as experienced today are often rooted in the historical development of societies. The impacts of colonialism, slavery, military conquest and discrimination based on class, gender, race and religion are visible today.

Billions of people around the world, in both wealthy and less affluent countries, are at this moment suffering under structural injustices. As demonstrated at Grenfell Tower, this is a recipe for disaster.

Structural injustice creates vulnerability

This disaster is quite a shock to British society. Although the contributing sociopolitical drivers (while sometimes not explicitly discussed) are perhaps more visible on this occasion, having struck a centre of wealth and power in London, we need to recognise that injustice lies at the core of almost all disasters.

At the Grenfell Tower and around the world, the poor and the marginalised suffer the most from disasters.

This injustice is not an accident – it is by design. There is no disaster that kills everyone in a particular locality nor one that knocks down all buildings in a single place.

Normally the resources to overcome the impact of natural hazards are available locally. The privileged have access to these resources while those at the margin do not.

Vulnerability to hazards, and related disasters, therefore mirrors how power and resources are unequally shared within societies. More often than not disasters affect people not because of a lack of knowledge about disasters, but because this knowledge is not applied.

Political decisions also put lives at risk. MP Chi Onwurah summarised appropriately when she wrote:

The residents of Grenfell were poor in a rich neighbourhood. They were those the market rejected, a burden on a borough apparently determined the rich should not pay to lift the constraints of the poor.

The British political class has failed to adequately represent the interests of its most vulnerable citizens for decades. That people are consigned to live in such conditions in a wealthy country is at best a betrayal of the vulnerable by the state. Some would call it criminal. It is not only the Tories who must swallow this bitter pill.

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Cities are battlegrounds

Cities tend to greatly magnify inequality. The Grenfell Tower disaster is a product of a deep societal divide in Britain, where wealth is increasingly concentrated among a small minority.

Gentrification is pushing already marginalised people out of sight and out of mind. This kind of urban development is a boon for housing market profiteers and supports the ruling class agenda, but neglects the needs of the most needy in society. Marginal people become resourceless, invisible to public policies, and disempowered in public life. This increases their vulnerability.

If cities are to reduce the risk of disasters like the Grenfell fire, we must focus on social justice in urban development. The benefits of development or redevelopment should prioritise the have-nots and provide dignity to people regardless of income or background. Cities that are able to provide opportunities for all citizens are also able to appreciate diversity rather than homogenisation.

The ConversationThe Grenfell Tower fire exposes the injustice of disaster, and this terrible moment must be learned from and acted upon. Pushing people to the margins and deeming them worthless is ultimately what causes them to perish.

Jason von Meding, Senior Lecturer in Disaster Risk Reduction, University of Newcastle; Giuseppe Forino, PhD Candidate in Disaster Management, University of Newcastle; J.C. Gaillard, Associate Professor, School of Environment, and Ksenia Chmutina, Lecturer in Sustainable and Resilient Urbanism, Loughborough University

This article was originally published on The Conversation. Read the original article.

New Zealand’s Alpine Fault reveals extreme underground heat and fluid pressure



File 20170517 24350 bor3lx
The drilling project at New Zealand’s Alpine Fault is the first to investigate a major fault that is due to rupture in a big earthquake in coming decades.
John Townend/Victoria University of Wellington, CC BY-SA

Rupert Sutherland, Victoria University of Wellington

An international team that drilled almost a kilometre deep into New Zealand’s Alpine Fault, which is expected to rupture in a major earthquake in the next decades, has found extremely hot temperatures and high fluid pressures. The Conversation

Our findings, published today in Nature, describe these surprising underground conditions. They have broad implications for understanding what happens in the buildup to a major earthquake, and may represent the discovery of a new type of geothermal energy resource.

Seismic forces building up

The Alpine Fault is one of the world’s major plate boundaries and New Zealand’s most hazardous earthquake-generating fault. It runs for 650 kilometres along the spine of New Zealand’s South Island and we know that it ruptures on average every 300 years, producing an earthquake of about magnitude 8.

The last time the Alpine Fault did this was in 1717, when it shunted land horizontally by eight metres and uplifted the mountains a couple of metres. It is expected to rupture in a major earthquake in the next few decades and, even though this may not happen in the next 30 years or even 100 years, we know that the fault is at the end of its seismic cycle.

Other projects around the world have drilled into major faults, but usually just after a major earthquake. The Deep Fault Drilling Project, which involved more than 100 scientists from 12 countries, gave us an opportunity to take a close look at a fault as it builds up to its next rupture. It is the first time this has ever been done on a major fault that is due to fail in coming decades.

Drilling into New Zealand’s most hazardous fault.

Hot water at depth

We drilled two holes and during our second attempt made it to 893 metres deep. As we drilled deeper, the temperature increased rapidly, at a rate of about 15 degrees Celsius per 100 metres in depth. This is much higher than the normal rate of about 3°C per 100m in depth. At a depth of 630 metres, the water at the bottom of the drill hole was hot enough to boil, if it had been allowed to rise to the surface. The high pressures at depth stop it from boiling.

The hottest boreholes on Earth are mostly found in volcanic regions. We discovered a geothermal gradient – a measure of how fast temperature increases with depth – that is similar to the hottest geothermal energy boreholes drilled into volcanoes of the central North Island; but there are no volcanoes near the Alpine Fault.

How does it get so hot

There are two processes we think explain the extreme underground conditions at our drill site. An earthquake on the Alpine Fault has two geological effects: mountains are pushed higher and the shaking breaks up rocks.

During an earthquake and over time, the fractured rocks come down in landslides and rivers carry them to the sea. This limits how high the mountains can get. This process has operated for millions of years, with the height of the mountains staying about the same. Eventually, hot rocks from great depth (about 30 kilometres deep, at 550°C) were transported to the surface quickly enough (on geological time scales) that they did not have time to fully cool. Heat is transported from depth by the rock movement.

The other process that helps explain our findings is the rock fracturing, which allows rain water and snow melt to percolate downwards into the mountains so fast that it can move heat towards the valley, where water wells up and discharges. The flow needs to be fast enough so that the heat is not lost along the way, just as a water pipe in your home moves heat from a hot water cylinder to your bath before having time to cool. Water flowing through the rock concentrates heat and raises fluid pressure beneath the valleys.

The hot, high-pressure water beneath the valleys is mostly invisible at the surface, because it mixes with shallow, cold groundwater that flows to a depth of about 50 metres at our drill site. However, most of the valleys in the region where we drilled have a few warm springs that hint at this deeper source of hot water.

Better modelling of future hazards

The unexpected results of our research are important beyond New Zealand. Other faults around the world that we know are similar to the Alpine Fault may also have extreme conditions that have never been investigated.

Perhaps most significantly, we can now describe and estimate conditions on a geological fault that will rupture in an earthquake. This will help us to develop better computer models of earthquake rupture. It may also help us to explain how some types of geology (for example certain types of gold mineralisation) have formed as a result of similar conditions in ancient earthquakes.

Economic benefits

The extreme underground conditions we discovered may result in substantial economic benefits for New Zealand by providing a sustainable and clean geothermal energy resource that could be used by industry and local communities. We expect that similar hot geothermal conditions exist in other nearby valleys, and maybe in some other places in the world that are geologically similar to western New Zealand.

More drilling and measurements are needed to establish the scale of this local resource, its possible uses, and if it is safe to develop.

Rupert Sutherland, Professor of tectonics and geophysics, Victoria University of Wellington

This article was originally published on The Conversation. Read the original article.

Northern NSW is no stranger to floods, but this one was different


Joelle Gergis, University of Melbourne

The devastating flood damage wreaked by Tropical Cyclone Debbie has left many residents in northern New South Wales facing an enormous cleanup that could take months. The Conversation

Any Lismore local will tell you that flooding is a fact of life in the Northern Rivers. In the floods of 1954 and 1974, the Wilsons River rose to a record 12.17 metres. This time around, the river peaked at 11.59m, breaching the flood levee built in 2005 for the first time.

So what are the conditions that caused those historic floods? And are they any different to the conditions of 2017?

Like the current flood, cyclonic rains also caused the 1954 and 1974 events. But unlike those past events, both of which were preceded by prolonged wet weather, almost all of the extreme rainfall from ex-Tropical Cyclone Debbie fell within 24 hours.

More interesting still is the fact that we are not currently experiencing La Niña conditions, which have historically formed the backdrop to severe flooding in eastern Australia.

The 1954 flood was preceded by an east coast low from February 9-11, followed by a decaying tropical cyclone from February 19-22. Thirty people were killed as flood records were set in Lismore, Kyogle, Casino, Nimbin and Murwillumbah. Some places received more than 1,000mm of rain in 14 days.

In 1974, former Tropical Cyclone Zoe unleashed torrential rain over Lismore, Wyrallah and Coraki. From March 10-13, some stations received almost 1,000mm in just four days. One analysis described the flood as a once-in-70-year event.

This time around, the remains of Tropical Cyclone Debbie delivered extreme rainfall to northern NSW towns including Murwillumbah, Chinderah and Lismore, despite having crossed the coast several days earlier and more than 1,200km to the north. Floods as far apart as Rockhampton in central Queensland and northern New Zealand show the storm’s colossal area of influence.

During the event, 20 rainfall stations in Queensland and 11 sites in NSW recorded their wettest March day on record. Mullumbimby, in the Brunswick River catchment, received a staggering 925mm during March – over half the annual average in a single month – causing major flooding in the region.

The heaviest rainfall in the Wilsons River catchment was at Terania Creek, which received 627mm over March 30-31, 99% of it in the 24 hours from 3am on March 30. Lismore recorded 324.8mm of rain in the 18 hours to 3am on March 31, its wettest March day in more than 100 years. A little further out of town, floodwaters submerged the gauge at Lismore Airport, so unfortunately we do not have reliable figures for that site.

March 2017 rainfall across Australia. Tropical Cyclone Debbie’s track down the east coast is visible in the trail of above-average falls.
Bureau of Meteorology

The main difference between the current flooding and the 1954 and 1974 floods is that the previous events both occurred against a background of sustained La Niña conditions. These tend to deliver above-average tropical cyclone activity and high rainfall totals, which increase flood risk.

During the early 1970s, Australia experienced the longest period of La Niña conditions in the instrumental record. This unleashed phenomenal deluges across virtually the entire country. By the end of 1973, many catchments were already saturated as the wet season started early, culminating in the wettest January in Australia’s rainfall records.

In 1974 the Indian Ocean was also unusually warm (what meteorologists call a “negative Indian Ocean Dipole (IOD) phase”), further enhancing rainfall in the region. When negative IOD events coincide with La Niña conditions in the tropical Pacific, the warm sea temperatures reinforce one another, resulting in more evaporation and increased rainfall. This double whammy resulted in the exceptionally wet conditions experienced across the country during 1974.

In January 1974, the Northern Territory, Queensland and Australia as a whole recorded their wettest month on record, while South Australia and New South Wales recorded their second-wettest January on record. Torrential monsoon rains in the gulf country of Queensland transformed the normally dry interior into vast inland seas, flooding all the way to Lake Eyre in the arid zone of South Australia.

Vast swathes of Australia were much wetter than average during the mid-1970s.
Bureau of Meteorology

In contrast, Tropical Cyclone Debbie formed under neutral conditions, rather than during a La Niña. In fact, the Bureau of Meteorology is currently on El Niño watch, meaning that there is double the normal risk of an El Niño event bringing low rainfall and high temperatures to Australia by mid-2017.

So, unlike the 1950s and 1970s, the current flooding happened despite the absence of conditions that have driven major flooding in the past. It seems extraordinary that such a damaging cyclone could develop under these circumstances, and deliver such high rainfall over such a short time. This suggests that other factors may be at play.

A rapidly warming climate means that storms are now occurring in a “super-charged” atmosphere. As temperatures increase, so does the water-holding capacity of the lower atmosphere. The oceans are also warming, especially at the surface, driving up evaporation rates. Global average surface temperature has already risen by about 1℃ above pre-industrial levels, leading to an increase of 7% in the amount of water vapour in the atmosphere.

Ocean evaporation, before and after ocean warming.
Climate Council

Of course, it is hard to determine the exact impact of climate change on individual storms. However, climate scientists are confident about the overall trends.

Australia’s land and oceans have warmed by 1℃ since 1910, with much of this warming occurring since 1970. This influences the background conditions under which both extremes of the rainfall cycle will operate as the planet continues to warm. We have high confidence that the warming trend will increase the intensity of extreme rainfall experienced in eastern Australia, including southeast Queensland and northern NSW.

While it will take more time to determine the exact factors that led to the extreme flooding witnessed in March 2017, we cannot rule out the role of climate change as a possible contributing factor.

CSIRO’s latest climate change projections predict that in a hotter climate we will experience intense dry spells interspersed with periods of increasingly extreme rainfall over much of Australia. Tropical cyclones are projected to be less frequent but more intense on average.

That potentially means longer and more severe droughts, followed by deluges capable of washing away houses, roads and crops. Tropical Cyclone Debbie’s formation after the exceptionally hot summer of 2016-2017 may well be a perfect case in point, and an ominous sign of things to come.

Joelle Gergis, ARC DECRA Climate Research Fellow, School of Earth Sciences, University of Melbourne

This article was originally published on The Conversation. Read the original article.

Tropical Cyclone Debbie has blown a hole in the winter vegetable supply


Ian Sinclair, University of Sydney; Brent Jacobs, University of Technology Sydney; Laura Wynne, University of Technology Sydney, and Rachel Carey, University of Melbourne

Cyclone Debbie, which lashed the Queensland coast a week ago, has hit farmers hard in the area around Bowen – a crucial supplier of vegetables to Sydney, Melbourne and much of eastern Australia. The Conversation

With the Queensland Farmers’ Federation estimating the damage at more than A$100 million and winter crop losses at 20%, the event looks set to affect the cost and availability of fresh food for millions of Australians. Growers are reportedly forecasting a price spike in May, when the damaged crops were scheduled to have arrived on shelves.

The incident also raises broader questions about the resilience of Australia’s fresh vegetable supply, much of which comes from a relatively small number of areas that are under pressure from climate and land use change.

In 2011 the Bowen area produced 33% of Australia’s fresh beans, 46% of capsicum and 23% of fresh tomatoes, making it the country’s largest producer of beans and capsicums, and number two in fresh tomatoes.

The region also produces a significant amount of chillies, corn, cucumbers, eggplant, pumpkin, zucchini and squash, and is a key production area for mangoes and melons.

Coastal Queensland’s vegetable regions are among the highest-producing in the country, especially for perishable vegetables. The Whitsunday region around Bowen, and the area around Bundaberg further south are each responsible for around 13% of the national perishable vegetable supply.

As the chart below shows, vegetable production is highly concentrated in particular regions, typically on the fringes of large cities. These “peri-urban” regions, when added to the two major growing areas in coastal Queensland, account for about 75% of Australia’s perishable vegetables.

Proportion of State Perishable Vegetable Production by weight.
ABS 7121.0 Agricultural Commodities Australia, 2010-11

Australia’s climate variability means that most fresh produce can be grown domestically. The seasonable variability allows production to move from the south to the north in the winter, when the Bundaberg and Bowen areas produce most of the winter vegetables consumed in Brisbane, Sydney and Melbourne. The Bowen Gumlu Growers Association estimates that during the spring growing season in September—October, the region produces 90% of Australia’s fresh tomatoes and 95% of capsicums.

Besides damaging crops, Cyclone Debbie has also destroyed many growers’ packing and cool storage sheds. The cost of rebuilding this infrastructure may be too much for many farmers, and the waterlogged soils are also set to make planting the next crop more difficult.

The recovery of production in these areas is crucial for the supply. Growers who have lost their May crop will first have to wait until the paddocks dry out, then source new seedlings and plant them. It could be weeks until crops can be replanted, and storage and processing facilities replaced.

The Queensland government has announced natural disaster relief funding, including concessional loans of up to A$250,000 and essential working capital loans of up to A$100,000, to help farmers replant and rebuild.

Meanwhile, consumers of fresh vegetables in Sydney and Melbourne and many other places are likely to find themselves paying more until the shortfall can be replaced.

Fresh food for growing cities

Australia’s cities are growing rapidly, along with those of many other countries. The United Nations has predicted that by 2050 about 87% of the world’s population will live in cities. This urban expansion is putting ever more pressure on peri-urban food bowls.

Food production is also under pressure from climate change, raising the risk of future food shocks and price spikes in the wake of disasters such as cyclones. Meanwhile, the desire for semi-rural lifestyles is also conflicting with the use of land for farming (see Sydney’s Food Futures and Foodprint Melbourne for more).

These pressures mean that Australia’s cities need to make their food systems more resilient, so that they can withstand food shocks more easily, and recover more quickly.

Key features of a resilient food system are likely to include:

  • geographic diversity in production, which spreads the risk of crop damage from extreme weather events across a number of different production areas;

  • more local food production, to reduce transportation and storage costs and avoid over-reliance on particular regions;

  • a diverse, healthy and innovative farming community;

  • greater consumer awareness of the importance of seasonal and locally produced food;

  • recycling of urban waste and water for use on farms, to reduce the use of fresh water and fertilisers;

  • the capacity to import food from overseas to meet shortfalls in domestic supply;

  • increased use of protected cropping systems such as greenhouses, which are better able to withstand adverse weather.

Two recent studies of food production around Sydney and Melbourne provide examples of a range of mechanisms and policies for increasing the resilience of the food systems of Australian cities.

Our food system has served us well until now, but land use pressures and climate change will make it harder in future. When a cyclone can knock out a major production region overnight, with knock-on effects for Australian consumers, this points to a lack of resilience in Australia’s fresh vegetable supply.

Ian Sinclair, PhD Candidate. Contested Landscapes – Managing the Tensions between Land Use Planning in Strategic Agricultural Regions on Australia’s Eastern Seaboard., University of Sydney; Brent Jacobs, Research Director, Institute for Sustainable Futures, University of Technology Sydney; Laura Wynne, Senior Research Consultant, Institute for Sustainable Futures, University of Technology Sydney, and Rachel Carey, Research Fellow, University of Melbourne

This article was originally published on The Conversation. Read the original article.

Cyclone Debbie: we can design cities to withstand these natural disasters


Rob Roggema, University of Technology Sydney

What happens after Cyclone Debbie is a familiar process. It has been repeated many times in cities around the world. The reason is that our cities are not designed for these types of events. The Conversation

So we know what comes next. Queenslanders affected by Debbie will complain about the damage, the costs and the need for insurers to act now to compensate their losses. The state and federal governments will extensively discuss who is to blame.

The shambles will be cleared and life will eventually get back to normal. Billions of dollars will be spent on relocating people and on repairing the damage and public works. A state-level levy may even be necessary to pay for all the extra costs. Two storms, Katrina and Sandy, cost the United States more than US$200 billion between them.

Yet we know what cyclones do. They bring, for a relatively short time, huge gusty winds. These are inconvenient but have proven not too damaging.

The greatest risk comes from storm surge and rainfall. Both bring a huge amount of water. And all this water has to find a way to get out of our living environment.

Despite knowing, approximately, where cyclones tend to occur, we never thought about adjusting our cities to their effects. It would make a huge financial difference if we did.

So, what can we do to build our cities differently to ensure the impacts of cyclones – and the accompanying rainfall and storm surges – do not disrupt urban life? The answer to all of this is design.

The usual design of current cities and towns brought us problems in the first place. We need to fundamentally rethink the design of our built-up areas.

Rethinking coastal and urban design

It starts with coastal design. We are used to building dams and coastal protection against storm surges happening once in 100 years. For comparison, the protection standards in the low-lying Netherlands are designed to protect the country against a once-in-10,000-years flood. But nature has proven to be stronger than our artificial constructs can handle.

An alternative design approach is to rely on the natural coastal processes of land forming – such as reefs, islands, mangroves, beaches and dunes. Humans can help the formation of these natural protectors by providing the triggers for them to emerge.

As an example, when we put sand in front of the coast, the currents and waves will transport the sand towards the coast and build up new and larger beaches. This example is realised in front of the Dutch coast and is known as the sand engine. But nature will build them up to form a much stronger system than humans ever could.

Instead of coasts, beaches and real estate being washed away, new land and larger beaches may be formed as a result of these processes. This requires design thinking, insights into the resilience of the coastal system, and understanding of the natural forces at play.

Second, urban design should reconsider the way we build our cities. Most urban areas do not have the capacity to “welcome” lots of water. And it is about lots of water, not the average shower or two.

Until cyclones are gone, these enormous amounts of water need to be stored for a short period in dense urban areas. This goes beyond water-sensitive urban design.

Despite the benefits of water-sensitive design in many urban developments, when the going gets tough, this is just not enough. Water-sensitive urban design can barely cope with average rainfall peaks. So, in times of severe weather events, cities need to have additional spaces to store all this water.

The general rule here is to store every raindrop as long as possible where it falls.

How and where should we redesign our cities?

So, what can be done to cyclone-proof our cities? We can:

  • Create larger green spaces, which are connected in a natural grid, increase the capacity of these green systems by adding eco-zones and wetlands, and redesign river and creek edges. Remove the concrete basins from every creek in the city.

  • Use large public spaces, such as parking spaces near shopping centres, ovals and football pitches, for temporarily capturing and storing excess rainwater. Small adjustments at the edges of these places are generally enough to capture the water.

  • Turn parking garages into temporary storage basins.

  • Redesign street profiles and introduce green and water-zones in streets. Out of every three-lane street, one lane can be transformed into a green lane, which can absorb rainwater.

  • Redesign all impervious, sealed spaces and turn these into areas where the water can infiltrate the soil. Use permeable materials.

  • Think in an integrated way about street infrastructure, green and ecological systems, and the water system.

These design interventions are not new and have been done abroad in cities such as Rotterdam, Hamburg or Stockholm. If we could add to these the redesign of roofs and gardens of industrial and residential estates and turn these into green roofs and rain gardens, the city would start to operate as a huge sponge.

When it rains, the city absorbs the huge amounts of water and releases it slowly to the creek and river system after the rain has gone. This way, green spaces and water spaces not only play an important role during and just after a cyclone, but they then add quality to people’s immediate living environment.

And maybe the best of all this: the bill Debbie and other natural disasters would present to government, industries and insurers could be much lower.

Rob Roggema, Professor of Sustainable Urban Environments, University of Technology Sydney

This article was originally published on The Conversation. Read the original article.