Floodplains aren’t separate to a river — they’re an extension of it. It’s time to change how we connect with them


Melissa Parsons, University of New England and Martin Thoms, University of New EnglandDramatic scenes of flood damage to homes, infrastructure and livelihoods have been with us on the nightly news in recent weeks. Many will be feeling the pain for years to come, as they contend with property damage, financial catastrophe and trauma.

But what if, for a moment, we removed the humans and their structures from these tragic images — what would we see?

We would see a natural process of river expansion and contraction, of rivers doing exactly what they’re supposed to do from time to time. We’d see them exceeding what we humans have deemed to be their boundaries and depositing sediment across their floodplains. We’d see reproductive opportunities for fish, frogs, birds and trees. The floods would also enrich the soils. Floods can be catastrophic for humans, but they are a natural part of an ecosystem from which we benefit.

These scenes clearly depict the intersection of humans and nature, and it’s not working out well for either side.




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5 ways the government can clean up the Murray-Darling Basin Plan


We must envision a new way of interacting with floodplains – these brilliant social-ecological systems that are not separate to rivers but rather part of the riverine landscape.

Humans can live on and with floodplains — but the way we do that has to change.

What is a floodplain?

Floodplains are relatively flat stretches of land located next to rivers. It helps to think of them as an extension of the river; it is natural and normal for a river to flood their adjacent plains.

Floodplains are composed of sediment the river has transported and then deposited, which makes them incredibly fertile. Flow and sediment regimes interacting over decades — or millennia — determine the physical and ecological character of floodplains, and the way they flood.

There are more than 15 generic floodplain types in Australia. Each harbours a unique set of evolutionary properties, physical features and ecosystems.

These influence the way floodwaters traverse floodplains, how long water remains on a floodplain, the velocity, turbulence and depth of floodwaters, and ecosystem responses to flooding. Floodplains are complex and highly variable.

Floodplains are also dynamic and ever-changing — and we should expect them to change even more in the coming years. Australian rivers have experienced regular periods of increased flood activity in the past 100 years.

And climate change is predicted to increase flood activity.




Read more:
5 ways the government can clean up the Murray-Darling Basin Plan


Humans benefit from floodplains

Floodplains are among the most productive ecosystems on the planet – they are biodiversity hotspots.

That’s in large part due to periodic flooding between different parts of a river-floodplain system; flooding is crucial to the function of floodplains. Without floods, these floodplains wouldn’t “work” — they would not be able to deliver the ecosystem services we benefit from. Those benefits include, but are not limited to:

  • food grown in these fertile soils
  • regulation of a balanced ecosystem
  • cultural heritage
  • transportation (as floodplains are easy to build roads on)
  • the supply of good quality drinking water
  • recreation.

The economic value of floodplain ecosystem services exceed US$25,681 per hectare. Roughly 25% of global terrestrial ecosystem services come from floodplains.

Humans are drawn to live on floodplains because of their productivity. In Australia, the floodplains of the Murray Darling Basin, heavily developed for agriculture, yield more than A$10 billion annually. These floodplain ecosystems provide an estimated A$187 billion per annum from their various ecosystem services.

However, the more we interrupt floodplain processes with development, the more we diminish the supply of ecosystem services.

The perils of living on floodplains

Putting the people back into the news footage reveals a social picture that is costly, traumatic and disruptive. The events of the past weeks have now brought into focus the perils of living on floodplains.

Humans have come up with ways to contend with this peril. Dams and levees. Land use planning. Building codes. Engineered floodscapes. Insurance. Emergency preparation systems and community engagement.

But if floodplains are a social-ecological system, where society gains great benefits but is also periodically placed at risk, which side should get the greatest policy attention? The humans or the ecosystem?

The answer is: both. But they also need to be better integrated.

Balancing the social with the ecological

Balancing the social and ecological aspects of floodplains requires a mindset change. We must combine community participation with research, resilience and adaptation to make long-term decisions about the future of these complex social-ecological systems.

If society wants to continue to derive the billions of dollars of benefits from floodplains, we need to ensure that flooding continues to occur on floodplains, and adapt to risk in imaginative and innovative ways that also protect the benefits.

Business as usual is not an option. The limitations of technocratic controls such as dams and levees should now be obvious. Time and time again, these have increased flood risk and failed to flood-proof the floodplain.

Rarely do such linear solutions solve complex problems in social-ecological systems. Linear solutions often exacerbate a problem or simply move it on to other parts of the system, creating social inequality, environmental decline and future risk.

The Australian government’s 2018 National Disaster Risk Reduction Framework sets the challenge to join up the built, social, economic and natural environments to address disaster risk in Australia.

Accepting the challenge requires a broader focus on balancing the social-ecological sides of Australia’s vast floodplains. Complexity, not linear thinking, must be embedded in the way we reimagine policy about floodplains and floods.

This requires transformative collaborations between government departments, researchers, business, and community stakeholders.


If this article has raised issues for you, or if you’re concerned about someone
you know, call Lifeline on 13 11 14. This story is part of a series The Conversation is running on the nexus between disaster, disadvantage and resilience. You can read the rest of the stories here.
The Conversation

Melissa Parsons, Senior Lecturer, Geography and Planning, University of New England and Martin Thoms, Professor of Physical Geography, University of New England

This article is republished from The Conversation under a Creative Commons license. Read the original article.

After the floods, stand by for spiders, slugs and millipedes – but think twice before reaching for the bug spray


Lukas Koch / AAP

Caitlyn Forster, University of Sydney; Dieter Hochuli, University of Sydney, and Eliza Middleton, University of SydneyRecord-breaking rain has destroyed properties across New South Wales, forcing thousands of people to evacuate and leaving hundreds homeless.

Humans aren’t the only ones in trouble. Many of the animals that live with and around us are also heading for higher ground as the floodwaters rise.

Often small creatures — especially invertebrates like spiders, cockroaches and millipedes — will seek refuge in the relatively dry and safe environments of people’s houses. While this can be a problem for the human inhabitants of the house, it’s important to make sure we don’t add to the ecological impact of the flood with an overzealous response to these uninvited guests.

Warragamba Dam in southwestern Sydney has been spilling a Sydney Harbour’s worth of water each day during the rains.
Eliza Middleton, Author provided

What floods do to ecosystems

Floods can have a huge impact on ecosystems, triggering landslides, increasing erosion, and introducing pollutants and soil into waterways. One immediate effect is to force burrowing animals out of their homes, as they retreat to safer and drier locations. Insects and other invertebrates living in grass or leaf litter around our homes are also displaced.

Burrowing invertebrates come to the surface during floods, providing food for opportunistic birds.
Dieter Hochuli, Author provided

Snakes have reportedly been “invading” homes in the wake of the current floods. Spiders too have fled the rising waters. Heavy rain can flood the burrows of the Australian funnelweb, one of the world’s most venomous spiders.

Some invertebrates will boom; others may plummet

Rain increases greenery, which can support breeding booms of animals such as mosquitoes, locusts, and snails.

Even species that don’t thrive after floods are likely to become more visible as they flock to our houses for refuge. But an apparent short-term increase in numbers may conceal a longer story of decline.




Read more:
After the floods come the mosquitoes – but the disease risk is more difficult to predict


After periods of flooding, the abundance of invertebrates can fall by more than 90% and the number of different species in an area significantly drops. This has important implications for the recovery of an ecosystem, as many of the ground dwelling invertebrates displaced by floods are needed for soil cycling and decomposition.

So before you reach for the bug spray, consider the important role these animals play in our ecosystem.

What to do with the extra house guests?

If your house has been flooded, uninvited creatures taking shelter in your house are probably one of the smaller issues you are facing.

Once the rain subsides, cleaning in and around your property will help reduce unwanted visitors. Inside your house, you may see an increase in cockroaches, which flourish in humid environments. Ventilating the house to dry out any wet surfaces can help get rid of cockroach infestations, and filling crevices can also deter unwanted visitors.




Read more:
Floods leave a legacy of mental health problems — and disadvantaged people are often hardest hit


In the garden, you may see an increase in flies in the coming weeks and months as they lay eggs in rotting plants. Consider removing any fruit and vegetables in the garden that may rot.

Mosquitoes are also one to watch as they lay eggs in standing water. Some species pose a risk of diseases such as Ross River virus. To prevent unwanted mozzies, make sure to empty things that have filled with rainwater, such as buckets and birdbaths.

If you do encounter one of our more dangerous animals in your home, such as venomous snakes and spiders, do not handle them yourself. If you find an injured or distressed snake, or are concerned about snakes in your house, call your local wildlife group who will be able to relocate them for you.

Just like the floods, which will subside as the water moves on, the uninvited gathering of animals is a temporary event. Most visitors will quickly disperse back to more appropriate habitat when the weather dries, and their usual homes are available again.

You may see an increase in slugs in your local area after rainy conditions.
Eliza Middleton @smiley_lize

Don’t sweat the small stuff

While many of the impacts of floods are our own making, through poor planning and development in flood-prone areas, effective design of cities and backyards can mitigate the risks of floods. Vegetation acts as a “sponge” for stormwater, and appropriate drainage allows water to flow through more effectively. Increasing backyard vegetation also provides extra habitat for important invertebrate species, including pollinators and decomposers.




Read more:
Not ‘if’, but ‘when’: city planners need to design for flooding. These examples show the way


With severe weather events on the rise, it is important to understand how ecosystems respond to, and recover from natural disasters. If invertebrates are unable to perform vital ecosystem functions, such as soil cycling, decomposition, and pollination, ecosystems may struggle to return to their pre-flood state. If the ecosystems don’t recover, we may see prolonged booms of nuisance pests such as mosquitoes.

A few temporary visitors are are a minor inconvenience in comparison to the impacts floods have on the environment, infrastructure and the health and well-being of people impacted. So while it may seem like a bit of a creepy inconvenience, maybe we should let our house guests stay until the flood waters go down.The Conversation

Caitlyn Forster, PhD Candidate, School of Life and Environmental Sciences, University of Sydney; Dieter Hochuli, Professor, School of Life and Environmental Sciences, University of Sydney, and Eliza Middleton, Laboratory Manager, School of Life and Environmental Sciences, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Yes, Australia is a land of flooding rains. But climate change could be making it worse


Etching of the 1867 flood in the Hawkesbury-Nepean Valley, depicting the Eather family.
illustrated Sydney News/author provided

Joelle Gergis, Australian National UniversityOver the past three years, I’ve been working on the forthcoming report by the United Nations’ Intergovernmental Panel on Climate Change. I’m a climate scientist who contributed to the chapter on global water cycle changes. It’s concerning to think some theoretical impacts described in this report may be coming to life – yet again – in Australia.

The recent flooding in New South Wales is consistent with what we might expect as climate change continues.

Australia’s natural rainfall patterns are highly variable. This means the influence climate change has on any single weather event is difficult to determine; the signal is buried in the background of a lot of climatic “noise”.

But as our planet warms, the water-holding capacity of the lower atmosphere increases by around 7% for every 1℃ of warming. This can cause heavier rainfall, which in turn increases flood risk.

The oceans are also warming, especially at the surface. This drives up both evaporation rates and the transport of moisture into weather systems. This makes wet seasons and wet events wetter than usual.

So while Australia has always experienced floods, disasters like the one unfolding in NSW are likely to become more frequent and intense as climate change continues.

People watch swollen river
Flooding is likely to become more severe as the planet warms.
AAP

Understanding the basics

To understand how a warming world is influencing the water cycle, it’s helpful to return to the theory.

From year to year, Australia’s climate is subject to natural variability generated by the surrounding Pacific, Indian and Southern oceans. The dominant drivers for a given year set up the background climate conditions that influence rainfall and temperature.

It is a combination of these natural climate drivers that makes Australia the land of drought and flooding rains.

However, Australia’s climate variability is no longer influenced by natural factors alone. Australia’s climate has warmed by 1.4℃ since national records began in 1910, with most of the warming occurring since 1970. Human-caused greenhouse emissions have influenced Australian temperatures in our region since 1950.

This warming trend influences the background conditions under which both extremes of the rainfall cycle will operate as the planet continues to warm. A warmer atmosphere can hold more moisture (higher water vapour content), which can lead to more extreme rainfall events.

A warmer atmosphere can hold more moisture which can lead to more extreme rainfall events.
Climate Council

Since the winter of 2020, Australia has been influenced by the La Niña phase of the El Niño–Southern Oscillation (ENSO). Historically, sustained La Niña conditions, sometimes with the help of a warmer than average Indian Ocean, have set the scene for severe flooding in eastern Australia.

During these events, easterly winds intensify and oceans around Australia warm. This is associated with the Walker Circulation – a giant seesaw of atmospheric pressure that influences the distribution of warm ocean waters across the Pacific Ocean.

The last La Niña occurred in 2010–2012. It led to widespread flooding across eastern Australia, with particularly devastating effects in Queensland. The event caused the wettest two-year period in the Australian rainfall record, ending the 1997–2009 Millennium Drought.

Oceanographers from UNSW studied the exceptional event. They demonstrated how a warmer ocean increased the likelihood of extreme rain during that event, primarily through increased transport of moist air along the coast.

Their analysis highlighted how long‐term ocean warming can modify rain-producing systems, increasing the probability of extreme rainfall during La Niña events.

It is important to point out that changes in large-scale atmospheric circulation patterns are still not as well understood as fundamental changes in thermodynamics. However, because regional rainfall changes will be influenced by both factors, it will take researchers time to tease everything out.

So what about climate change?

The theoretical changes to the global water cycle are well understood. However, determining the contribution of natural and human influences on climate variability and extremes – known as “attribution” – is still an emerging science.

More studies are needed to distinguish natural or “background” rainfall variability from recent human-caused changes to the water cycle. This is particularly the case in a country like Australia, which has very high yearly rainfall variability. This contrasts with some regions of the Northern Hemisphere with less variable rainfall, where a clear climate change signal has already emerged.

Right now, La Niña conditions are decaying in the Pacific Ocean. As expected, the 2020–2021 La Niña has brought above-average rainfall to much of eastern Australia. This helped ease the severe drought conditions across eastern Australia since 2017, particularly in NSW.

NSW rainfall total, week ending March 22, 2021
NSW rainfall totals for the week ending March 22, 2021.
Bureau of Meteorology

What’s interesting about the 2020–2021 La Niña is that it was weak compared with historical events. The relationship between La Niña and rainfall is generally weaker in coastal NSW than further inland. However, it’s concerning that this weak La Niña caused flooding comparable to the iconic floods of the 1950s and 1970s.

The rainfall totals for the current floods are yet to be analysed. However, early figures reveal the enormity of the downpours. For example, over the week to March 23, the town of Comboyne, southwest of Port Macquarie, recorded an extraordinary 935mm of rainfall. This included three successive days with more than 200mm.

The NSW coast is no stranger to extreme rainfall – there have been five events in the past decade with daily totals exceeding 400mm. However, the current event is unusual because of its duration and geographic extent.

It’s also worth noting the current extreme rainfall in NSW was associated with a coastal trough, not an East Coast Low. Many of the region’s torrential rainfall events in the past have resulted from East Coast Lows, although their rainfall is normally more localised than has been the case in this widespread event.

Remember that as the air warms, its water-holding capacity increases, particularly over the oceans. Current ocean temperatures around eastern and northern Australia are about 1℃ warmer than the long-term average, and closer to 1.5℃ warmer than average off the NSW coast. These warmer conditions are likely to be fuelling the systems driving the extreme rainfall and associated flooding in NSW.

Sea surface temperature anomalies along the NSW coast.
Bureau of Meteorology

A nation exposed

Weather and climate are not the only influences on extreme flood events. Others factors include the shape and size of water catchments, the presence of hard surfaces in urban areas (which cant’t absorb water), and the density of human settlement in flood-prone areas.

The Hawkesbury–Nepean region in Western Sydney, currently experiencing major flooding, is a prime example. Five major tributaries, including the Warragamba and Nepean Rivers, flow into this extensively urbanised valley.

Improving our understanding of historical weather data may help improve future climate change risk assessment. For example, past floods in the Hawkesbury–Nepean have been a lot worse than the current disaster. In 1867, the Hawkesbury River at Windsor reached 19.7 metres above normal, and in 1961 peaked at 14.5 metres. This is worse than the 13.12 metres above normal recorded at Freemans Reach on March 23.

It’s sobering to think the Hawkesbury River once peaked 6 metres higher than what we’re seeing right now. Imagine the potential future flooding caused by an East Coast Low during strong La Niña conditions.

It will take time before scientists can provide a detailed analysis of the 2020–2021 La Niña event. But it’s crystal clear that Australia is very exposed to damage caused by extreme rainfall. Our theoretical understanding of water cycle changes tells us these events will only become more intense as our planet continues to warm.The Conversation

Joelle Gergis, Senior Lecturer in Climate Science, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The bushfires are horrendous, but expect cyclones, floods and heatwaves too



Bushfires are not the only weather and climate events set to ravage Australia in coming months.
Dave Hunt/AAP

Neville Nicholls, Monash University

Public attention on the disastrous bushfire crisis in Australia will rightly continue for weeks to come. But as we direct resources to coping and recovery, we should not forget other weather and climate challenges looming this summer.

The peak time for heatwaves in southern Australia has not yet arrived. Many parts of Australia can expect heavy rains and flooding. And northern Australia’s cyclone season is just gearing up.

The events will stretch the ability of emergency services and the broader community to cope. The best way to prepare for these events is to keep an eye on Bureau of Meteorology forecasts.

Fires and other extreme events will test emergency services this summer.
Darren Pateman/AAP

Let it rain

2019 was Australia’s driest year on record. Since early winter the Bureau of Meteorology has correctly predicted the development of these widespread dry conditions.

But relief may be coming. The latest bureau outlooks suggest more normal summer conditions from February to April. If it eventuates, this would include more rain.




Read more:
How to monitor the bushfires raging across Australia


The arrival of drought-breaking rains is notoriously hard to predict – in the past, they have come any time between January and May. Global warming is also complicating seasonal climate predictions.

We all hope the rain arrives sooner rather than later, and eases the fire situation. But rain will bring other risks.

Continental-scale droughts such as that experienced over the past few years are often broken by widespread heavy rains, leading to an increased risk of flooding including potentially lethal flash floods. The decade-long Millenium drought that ended in 2009 was followed by two extremely wet years with serious flooding.

A similar situation was seen in Indonesia in recent days when very heavy rains after a prolonged drought produced disastrous floods and landslides.

Indonesian rescuers searching for missing people after a landslide in West Java, Indonesia, triggered by heavy rain.
EPA

The flood risk is exacerbated by the bare soil and lack of vegetation caused by drought, and by bushfires that destroy forest and grassland.

Australia’s north may be particularly hard hit. The onset of the tropical wet season has been very much delayed, as the bureau predicted. Over the last three months, some parts of the Australian tropics had their lowest ever October-December rainfall. But there are some suggestions widespread rain may be on its way.

Further south, drought-breaking rains can also be heavy and widespread, leading to increased flood risk. So even when the drought breaks and rains quell the fires, there will likely still be bouts of extreme weather, and high demand for emergency services.

Cyclones and heatwaves

The tropical cyclone season has been much delayed, as predicted by the bureau, although there are now signs of cyclonic activity in the near future.

Cyclones often bring welcome rains to drought-affected communities. But we should not overlook the serious damage these systems may bring such as coastal flooding and wind damage – again requiring intervention from emergency services.




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And we are still a month away from the riskiest time for heatwaves in southern Australia. We’ve already had some severe heatwaves this summer. However they usually peak in the middle and end of summer, so the worst may be yet to come.

Lives have undoubtedly been saved this summer by improved forecasting of high temperatures and better dissemination of heatwave information by state and local governments. But after an already devastating early summer of fires and heat, warning fatigue may set in amongst both warning providers and the public. We must ensure heatwave warnings continue to be disseminated to populations at risk, and are acted on.

Shop staff clean up storm waters after Cyclone Debbie hit iQueensland in 2017.
AAP

Be thankful for weather forecasters

The recent experience of farmers, fire fighters, water resource managers and communities illustrate the value of the service provided by the Bureau of Meteorology. Greatly improved weather and climate forecasting developed over the past few decades means communities can plan for and deal with our highly variable weather and climate far better than in the past.




Read more:
It’s only October, so what’s with all these bushfires? New research explains it


Recent drought, fires and heatwaves – exacerbated by global warming – have been devastating. But imagine if we only had the limited weather forecast capabilities of even a few decades ago, without today’s high-speed computers to run weather forecast models, and satellites to feed in enormous amounts of data. How much worse would the impacts have been?

These forecasts have allowed heat alerts to be disseminated to vulnerable communities. Detailed information on weather conducive to fire spread has helped fire agencies provide more targeted warnings and direct resources appropriately.

An air tanker makes a pass to drop fire retardant on a bushfire in North Nowra, NSW, as fires spread rapidly.
Mick Tsikas/AAP

Never before have weather forecasts been so readily available to the public. Here are ways you can use them to reduce risks to life and property during an extreme event:

  • Listen to ABC local radio for emergency updates and detailed Bureau of Meteorology forecasts
  • load your state fire service emergency app onto your phone and check it regularly. Or check out the information online, such as at the NSW Rural Fire Service’s Fires Near Me website
  • check the bureau’s website for climate and weather forecasts
  • download a short-range rainfall forecast app such as Rain Parrot onto your phone. These apps use the bureau’s radar data to make short-range forecasts of rainfall for your location, and notify you if rain is coming.

Global warming is already lengthening the fire season and making heatwaves more intense, more frequent, and longer. It is also increasing the likelihood of heavy rains, and making droughts worse.

We must keep adapting to these changing threats, and further improve our ability to forecast them. And the community must stay aware of the many weather and climate extremes that threaten lives and property.The Conversation

Neville Nicholls, Professor emeritus, School of Earth, Atmosphere and Environment, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Climate explained: why coastal floods are becoming more frequent as seas rise



As sea levels rise, it becomes easier for ocean waves to spill further onto land.
from http://www.shutterstock.com, CC BY-ND

James Renwick, Victoria University of Wellington


CC BY-ND

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz

I saw an article claiming that “king tides” will increase in frequency as sea level rises. I am sceptical. What is the physics behind such a claim and how is it related to climate change? My understanding is that a king tide is a purely tidal effect, related to Moon, Sun and Earth axis tilt, and is quite different from a storm surge.

This is a good question, and you are right about the tides themselves. The twice-daily tides are caused by the gravitational forces of the Moon and the Sun, and the rotation of the Earth, none of which is changing.

A “king” tide occurs around the time when the Moon is at its closest to the Earth and Earth is at its closest to the Sun, and the combined gravitational effects are strongest. They are the highest of the high tides we experience.

But the article you refer to was not really talking about king tides. It was discussing coastal inundation events.




Read more:
King tides and rising seas are predictable, and we’re not doing enough about it


When tides, storms and sea levels combine

During a king tide, houses and roads close to the coast can be flooded. The article referred to the effects of coastal flooding generally, using “king tide” as a shorthand expression. We know that king tides are not increasing in frequency, but we also know that coastal flooding and coastal erosion events are happening more frequently.

As sea levels rise, it becomes easier for ocean waves to penetrate on to the shore. The biggest problem arises when storms combine with a high tide, and ride on top of higher sea levels.

The low air pressure near the centre of a storm pulls up the sea surface below. Then, onshore winds can pile water up against the coast, allowing waves to run further inshore. Add a high or king tide and the waves can come yet further inshore. Add a bit of sea level rise and the waves penetrate even further.

The background sea level rise has been only 20cm around New Zealand’s coasts so far, but even that makes a noticeable difference. An apparently small rise in overall sea level allows waves generated by a storm to come on shore much more easily. Coastal engineers use the rule of thumb that every 10cm of sea level rise increases the frequency of a given coastal flood by a factor of three.

This means that 10cm of sea level rise will turn a one-in-100-year coastal flood into a one-in-33-year event. With another 10cm of sea level rise, it becomes a one-in-11-year event, and so on.

Retreating from the coast

The occurrence rates change so quickly because in most places, beaches are fairly flat. A 10cm rise in sea levels might translate to 30 or 40 metres of inland movement of the high tide line, depending on the slope of the beach. So when the tide is high and the waves are rolling in, the sea can come inland tens of metres further than it used to, unless something like a coastal cliff or a sea wall blocks its way.

The worry is that beaches are likely to remain fairly flat, so anything within 40 metres of the current high tide mark is likely to be eroded away as storms occur and we experience another 10cm of sea level rise. If a road or a house is on an erodible coast (such as a line of sand dunes), it is not the height above sea level that matters but the distance from the high tide mark.

Another 30cm of sea level rise is already “baked in”, guaranteed over the next 40 years, regardless of what happens with greenhouse gas emissions and action on climate change. By the end of the century, at least another 20cm on top of that is virtually certain.




Read more:
Our shameful legacy: just 15 years’ worth of emissions will raise sea level in 2300


The 30cm rise multiplies the chances of coastal flooding by a factor of around 27 (3x3x3) and 50cm by the end of the century increases coastal flooding frequency by a factor of around 250. That would make the one-in-100-year coastal flood likely every few months, and roads, properties and all kinds of built infrastructure within 200 metres of the current coastline would be vulnerable to inundation and damage.

These are round numbers, and local changes depend on coastal shape and composition, but they give the sense of how quickly things can change. Already, key roads in Auckland (such as Tamaki Drive) are inundated when storms combine with high tides. Such events are set to become much more common as sea levels continue to rise, to the point where they will become part of the background state of the coastal zone.

To ensure cities such as Auckland (and others around the world) are resilient to such challenges, we’ll need to retreat from the coast where possible (move dwellings and roads inland) and to build coastal defences where that makes sense. The coast is coming inland, and we need to move with it.The Conversation

James Renwick, Professor, Physical Geography (climate science), Victoria University of Wellington

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Catastrophic Queensland floods killed 600,000 cattle and devastated native species


Gabriel Crowley, James Cook University and Noel D Preece, James Cook University

In February, about 600,000 cattle were killed by catastrophic flooding across north Queensland’s Carpentaria Gulf plains.

The flood waters rose suddenly, forming a wall of water up to 70km wide. Record depths were reached along 500km of the Flinders River, submerging 25,000 square kilometres of country. Cattle were stranded. Many drowned.




Read more:
Queensland’s floods are so huge the only way to track them is from space


Even though cattleman Harry Batt lost 70% of his herd, he was more concerned about the wildlife. He said, “all the kangaroos, and bloody little marsupial mice and birds, they couldn’t handle it”.

Harry was right to be concerned. As our research, published today in Austral Ecology, reveals, floods sweeping Australia’s plains have disrupted native species for millions of years. Now, as climate change drives more intense flooding, we will see this effect intensify.

Flooding causes major disruptions to gene flow

February’s flood came ten years to the day after a far bigger flood on the adjoining river systems that submerged an area larger than Ireland. It was this flood that first drew our attention to the plight of native species.

Noel was asked by Northern Gulf Resource Management Group to survey wildlife in areas affected by the 2009 flood. Over the following four years, he found almost no ground-dwelling reptiles, despite them occurring elsewhere in the region. They appeared to have been washed away or drowned.

Biologists have long known that many species’ ranges are interrupted by the Gulf Plains. Hence, these floodplains are considered one of Australia’s most important biogeographic barriers: the Carpentarian Gap.

Many closely related species with a common ancestor are separated by this Gap, including the Golden-shouldered Parrot of Cape York Peninsula and the Hooded Parrot of the Northern Territory. They are thought to have separated around 7 million years ago.




Read more:
South-East Queensland is droughtier and floodier than we thought


The Gap also separates many other species, including birds, mammals, reptiles and butterflies, at the subspecies or genetic level. Even more species found on either side are just absent from the Gulf Plains.

Huge flooding across the Gulf Plains, including the Norman and Flinders Rivers, in February 2009.
NASA Worldview, CC BY-SA

Flood impacts are immense and under-appreciated

When biologists first tried to find a reason for these patterns, they only considered aridity. They proposed Australia’s arid zone expanded to the Gulf of Carpentaria during ice ages.

There is no evidence for this, but the misunderstanding is completely understandable.

Any dry-season visitor to the Gulf Plains will find a dry, inhospitable environment with few trees or shrubs for shade, cracked clay soils, and lots of flies. European explorers described the region as “God-forsaken”.

But it can be quite a different place in the wet season.

Rains in the Gulf are caused by the summer monsoonal troughs or cyclones. About once a decade, these generate massive downpours. Historical records show at least 14 major floods since 1870.

So, to us, it seemed floods rather than aridity could be the cause of the odd distributions of plants and animals.

We set out to see whether Noel’s findings could have been caused by flooding or whether other factors such as soil, vegetation or climate were more important.

We also wanted to know what other effects floods might have on the region’s ecosystem. Could floods, by eliminating trees and shrubs, be responsible for the hostile appearance of the region? Could ground-dwelling reptiles and birds be underrepresented, not just at Noel’s sites, but on floodplains across the area?

To find out, we divided the area into floodplains and higher-altitude land, and generated 10,000 random sites across the Gulf Plains. We extracted soil, vegetation and rainfall data from national information sources, and examined the patterns.

We found trees and shrubs were significantly less common on floodplains than on land above the flood zone, regardless of soil or rainfall, and tree cover was further reduced on cracking clays. We concluded the plain’s open, hostile appearance is caused by a combination of soils and flooding.

We then examined all gecko, skink and bird records from the Atlas of Living Australia.

We found ground-living reptiles and birds were much less common on the floodplains, regardless of vegetation or soil. As expected, reptiles were more sensitive to flooding than birds, which can fly to safety during floods.

Finally, we found the sites affected by the 2009 flood had significantly fewer geckos and skinks than other sites across the Gulf Plains.

Increased flooding from climate change could have major consequences

Our findings have evolutionary significance that extends into the future. Repeated disruption of species across their distributions affects gene flow and ultimately produces new species. If floods become more frequent, as expected under climate change, so might the rates at which new species form.

They also have serious land management implications. Climate change planning emphasises conserving river corridors as safe refuges from arid conditions. However, periodic scouring of many of the nation’s floodplains – expected to increase under climate change – means that this approach needs rethinking.




Read more:
Townsville floods show cities that don’t adapt to risks face disaster


We conclude that on the most arid occupied continent on Earth, unpredictable floods may cause the most disruption to the Australian plant and animal life.The Conversation

Gabriel Crowley, Adjunct Principal Research Fellow, James Cook University and Noel D Preece, Adjunct Asssociate Professor, James Cook University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Heatwaves and flash floods: yes, this is Britain’s ‘new normal’


Hayley J. Fowler, Newcastle University

“It’s hard to believe, isn’t it, that we had a heatwave just last week?”

Those words were spoken by a BBC news presenter, in front of graphic images of fire service rescues, as heavy rain caused floods and landslides which closed many roads and railway lines. In recent days there have dramatic floods across the north of England, particularly around Manchester, the Peak District and Yorkshire.

For me, this is personal, as I am from the worst affected area. I went to high school where people spent the night in their Civic Hall. Three miles away from where I grew up, a dam holding back Toddbrook Reservoir has been at risk of collapse and the town of Whaley Bridge was evacuated. But I’m not surprised that we are seeing flash flooding and I expect it to get worse in the future.

I am a professor at Newcastle University, where I lead a large research group focused on understanding changes to intense rainfall events and flash floods. Over the past eight years we’ve been working closely with colleagues at the UK Met Office to develop new very high-resolution climate models that can simulate these very intense summer storms and therefore predict what might happen in a warming climate.

Our models tell us that by 2080 summers in the UK will be much hotter and drier. Heatwaves will be more common. In fact a report released by the Met Office on the same day as the latest flash floods tells us that heatwaves are already happening more often. When Cambridge recently hit 38.7℃, the UK became one of 12 countries to break its national temperature record this year.

The world is warming. But although UK average summer rainfall is predicted to decrease, our models tell us that when it does rain it will be more intense than has been the case. Flash flooding in the UK is generally caused by intense rainstorms, where more than 30mm falls in an hour. Climate models predict these will happen five times more often by 2080.

Part of the reason for this is the simple fact that warmer air can hold more moisture. But that’s too simple: the availability of moisture also increases in areas close to warm oceans – warmer sea surface temperatures cause more moisture to be evaporated into the atmosphere, providing additional fuel for these intense storms. And here’s the scary bit: the Atlantic Ocean provides a vast source of moisture for storms in the UK.

But that’s not the whole story. Heavy, short rain storms are intensifying more rapidly than would be expected with global warming (what we call the Clausius-Clapeyron relationship). Research also suggests that more intense storms can themselves grow bigger, and with both the intensity of the rainfall and the spatial footprint of the storm increasing, the total rainfall in an “event” could double.

What’s more, the larger storms seem to have an ability to draw in more moisture from the surrounding area and become even more intense: the additional energy (heating) fuelling the uplift of air within the storm’s core draws in even more moisture from the surface, allowing them to grow even larger, with more potential for flooding. These also provide the perfect ingredients for large hail storms.

So, it is entirely consistent that we might expect both more heatwaves and more intense summer thunderstorms in a warmer climate. We also know which areas of the country are already susceptible to these flash floods from our analysis of historical records of flooding. Newspapers have reported on the dramatic impacts of these floods for centuries and this has allowed my team to reconstruct a flash-flooding history of the UK.

Certain parts of the country are highly vulnerable as their rivers respond quickly to rainstorms. These rivers tend to be found in steep, upland catchments underlain by non-permeable rocks, mainly in the north and west of the UK. High-risk catchments also include urban areas where the ground is also non-permeable, for entirely different reasons.

Many of the towns reported to have suffered “biblical” flooding recently have suffered repeated flooding through history, but perhaps not within living memory. For example, Whaley Bridge is mentioned twice in the flood chronologies for events in June 1872 and July 1881:

On 19th [June 1872] the Goyt was 12 to 14 feet above its normal level. At Whaley Bridge houses near the river were completely flooded and people were taken into the chapel and inns … in Macclesfield a woman and child were drowned when the river Bollin overflowed. Two reservoirs burst in the vicinity.

This rich archive of knowledge, including the prevalence of flooding in certain towns, even specific roads, is something we should draw upon in planning both the emergency response to these flash floods and for reducing their future impact. We can learn a lot from the past in how to manage the greater risks of flooding the future will bring.The Conversation

Hayley J. Fowler, Professor of Climate Change Impacts, Newcastle University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Townsville floods show cities that don’t adapt to risks face disaster


Cecilia Bischeri, Griffith University

A flood-ravaged Townsville has captured public attention, highlighting the vulnerability of many of our cities to flooding. The extraordinary amount of rain is just one aspect of the disaster in Queensland’s third-biggest city. The flooding, increasing urban density, the management of the Ross River Dam, and the difficulties of dealing with byzantine insurance regulations have left the community with many questions about their future.

These questions won’t be resolved until we enhance the resilience of cities and communities against flooding. Adaptation needs to become an integral part of living with the extremes of the Australian environment. I discuss how to design and create resilient urban landscapes later in this article.




Read more:
Queensland’s floods are so huge the only way to track them is from space


Flood risk and insurance

Another issue that affects many households and businesses is the relationship between insurance claims and 1-in-100-year flood event overlay maps. Projected rises in flood risks under climate change have led to concerns that parts of Townsville and other cities will become “uninsurable” should the costs of cover become prohibitive for property owners.

Council flood data used for urban planning and land-use strategies is also used by insurers to assess the flood risk to individual properties. Insurers then price the risk accordingly.




Read more:
Lessons in resilience: what city planners can learn from Hobart’s floods


However, in extraordinary circumstances, when the flooded land is actually larger than the area marked by the flood overlay map, complications emerge. In fact, that part of the community living outside the map’s boundaries is considered flood-free. Thus, those pockets of the community may have chosen not to have flood insurance and not have emergency plans, which leaves them even worse off after floods. This is happening in Townsville.

Yet this is nothing new. Many people experienced very similar circumstances in 2011. Flood waters covered as much land as Germany and France combined. Several communities were left on their knees.

Notwithstanding the prompt and vast response of the federal government and Queensland’s state authorities, a few years later Townsville is going through something alarmingly similar.

Adaptation to create resilient cities

To find a solution, we need to rethink how to implement the Queensland Emergency Risk Management Framework. That is no easy task. However, it starts with shifting the perspective on what is considered a risk – in this case, a flooding event.

Floods, per se, are not a natural disaster. Floods are part of the natural context of Queensland as can be seen below, for instance, in the Channel Country.

Floods are part of the Australian landscape. Here trees mark the seasonal riverbeds in the Queensland outback between Cloncurry and Mount Isa.
Cecilia Bischeri, Author provided

The concept of adaptation as a built-in requirement of living in this environment then becomes pivotal. In designing and developing future-ready cities, we must aim to build resilient communities.

This is the ambitious project I am working on. It involves different figures and expertise with a shared vision and the support of government administrations that are willing to invest in a future beyond their elected term of office.

Ideas for Gold Coast Resilientscape

I live and work in the City of Gold Coast. Water is a fundamental part of the city’s character and beauty. In addition to the ocean, a complex system of waterways shapes a unique urban environment. However, this also exposes the city to a series of challenges, including flooding.

Last September, an updated flood overlay map was made available to the community. The map takes into account the projections of a 0.8 metre increase in the sea level and 10% increases in storm tide intensity and rainfall intensity.

These factors are reflected in the 1-in-100-year flood overlay. It shows undoubtedly that the boundaries between land and water are changeable.

Building walls between the city and water as the primary flood protection strategy is not a solution. A rigid border can actually intensify the catastrophe. New Orleans and the levee failures during the passage of Hurricane Katrina in 2005 provide a stark illustration of this.

Instead, what would happen and what would our cities look like if we designed green and public infrastructures that embody flooding as part of the natural context of our cities and territory?




Read more:
Design for flooding: how cities can make room for water


The current project, titled RESILIENTSCAPE: A Landscape for Gold Coast Urban Resilience, considers the role of architecture in enhancing the resilience of cities and communities against flooding. The proposal, in a nutshell, explores the possibilities that urban landscape design and implementation provide for resilience.

RESILIENTSCAPE focuses on the Nerang River catchment and the Gold Coast Regional Botanic Gardens, in the suburb of Benowa. The river and gardens were adopted as a case study for a broader strategy that aims to promote architectural solutions for a resilient City of Gold Coast. The project investigates the possibility of using existing green pockets along the Nerang River to store and retain excess water during floods.

Gold Coast Regional Botanic Gardens is one of the green areas along the Nerang River that could be used to store and retain flood water.
Batsv/Wikimedia Commons, CC BY-SA

These green spaces, however, will not just serve as “water tanks”. If mindfully planned, the green spaces can double up as public parks and facilities. This would enrich the community’s social realm and maximise their use and return on investment.

The design of a landscape responsive to flooding can, by improving local urban resilience, dramatically change the impact of these events.

The goal of creating urban areas that are adaptive to an impermanent water landscape is the main driver of the project. New Orleans after Hurricane Katrina and New York after Sandy are investing heavily in this direction and promoting international design competitions and community participation to mould a more resilient future. Queensland, what are we waiting for?




Read more:
Floods don’t occur randomly, so why do we still plan as if they do?



This article has been updated to clarify the use of flood data by insurers in assessing risk and the cost of cover.The Conversation

Cecilia Bischeri, Lecturer in Architecture, Griffith University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

South-East Queensland is droughtier and floodier than we thought



File 20180620 137734 1bzxjzp.jpg?ixlib=rb 1.1
South-East Queensland residents need to prepare for more regular floods, according to new data.
Shutterstock

Jack Coates-Marnane, Griffith University; Joanne Burton, Griffith University; John Tibby, University of Adelaide; Jon Olley, Griffith University; Joseph M. McMahon, Griffith University, and Justine Kemp, Griffith University

New data recording the past 1,500 years of flows in the Brisbane River have revealed that South-East Queensland’s climate – once assumed to be largely stable – is in fact highly variable.

Until now, we have only had access to 200 years of weather records in South-East Queensland. But our new research used marine sediment cores (dirt from the bottom of the ocean) to reconstruct stream flows and rainfall over past millennia.

This shows that long droughts and regular floods are both prominent features in South-East Queensland’s climate.

This is concerning. Decisions about where we build infrastructure and how we use water have been based on the assumption that our climate – especially rainfall – is relatively stable.




Read more:
Old floods show Brisbane’s next big wet might be closer than we think


Archives of past climates

Natural archives of climate are preserved within things such as tree rings, coral skeletons, ice cores, lake or marine sediments. Examining them lets us extend our climate records back beyond documented history.

We can then undertake water planning in the context of a longer record of climate, instead of our short-term instrumental records.

In this study, we used sediment cores from Moreton Bay (next to the mouth of the Brisbane River) to reconstruct the river’s flow over the past 1,500 years. In these cores we measured various indicators of fresh water to reconstruct a record of streamflow and regional rainfall.

At the turn of the last millennium the region was in the middle of a prolonged dry spell that lasted some six centuries, from roughly the year 600 to 1200. After about 1350 the region became gradually wetter, with peaks revealing a series of extreme floods in the late 1600s and early 1700s. Large floods in the 1700s have also been documented in the upper reaches of the catchment, in the Lockyer Valley.

These broad shifts in regional rainfall and streamflow are linked to drivers of global climates, including hemispheric cooling and the El Niño-Southern Oscillation.




Read more:
Explainer: El Niño and La Niña


A cool La Niña-dominant climate that persisted from roughly 1350 until 1750 caused increased rainfall and reduced evaporation.

In addition, the southward displacement of monsoon troughs at this time may have increased the likelihood of cyclone-related weather systems reaching southern Queensland.

This information helps us contextualise the climate of the last 200 years and gives us some insights into how regional rainfall responds to shifts in global climate.

Wet and dry extremes

Over the past 20 years, South-East Queensland has experienced its fair share of extreme weather events. Severe floods have caused deaths and damaged infrastructure. Flooding cost the Australian economy some A$30 billion in 2011.

Regular droughts may mean South-East Queensland needs to rethink water resource strategies.
Shutterstock

The millennium drought, which in this region was most severe from 2003-08, resulted in widespread water shortages. This prompted major investment in the South-East Queensland Water Grid, a connected network of dams, water treatment plants, reservoirs, pump stations and pipelines.

So far Queensland has coped with everything Mother Nature has thrown at it. But what if extreme floods and droughts became the norm rather than the exception?




Read more:
Floods don’t occur randomly, so why do we still plan as if they do?


Water quality is getting worse

The 2011 and 2013 floods highlighted the vulnerability to these extreme events of Brisbane’s major water treatment facility at Mt Crosby. The drinking water supply to the city in 2013 became too muddy for purification. The 2011 flood was also alarmingly muddy.

Such events also threaten the ecosystem health of downstream waterways, including the iconic Moreton Bay

Our reconstruction found that big floods over the past 1,500 years rivalled the size of floods in recorded history (1893, 1974 and 2011), but the level of sediment in the water of more recent floods seems to be unprecedented.

This indicates that historical and ongoing land-use changes in the Brisbane River catchment are contributing to more abrupt and erosive floods.

This will continue unless better land management techniques are adopted to improve the resilience of catchments to extreme weather events.

What does this mean for the future?

We are learning that over the last millennium natural climate and rainfall have been more variable than previously thought. This means that modern anthropogenic climate change may be exacerbated by a background of already high natural climate variability.

In addition, our water infrastructure has been built based on a narrow understanding of natural climate variability, limited to the last 200 years. This may mean the quantity of reliable long-term freshwater resources in eastern Australia has been overestimated.


The Conversation


Read more:
Droughts & flooding rains: what is due to climate change?


Jack Coates-Marnane, Post-doctoral research fellow, Griffith University; Joanne Burton, Adjunct Research Fellow, Griffith University; John Tibby, Senior Lecturer in Environmental Change, University of Adelaide; Jon Olley, Professor of Water Science, Griffith University; Joseph M. McMahon, PhD candidate, Griffith University, and Justine Kemp, Senior Research Fellow in Geomorphology, Griffith University

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

Floods don’t occur randomly, so why do we still plan as if they do?


Anthony Kiem, University of Newcastle

Most major floods in South East Queensland arrive in five-year bursts, once every 40 years or so, according to our new research.

Yet flood estimation, protection and management approaches are still designed on the basis that flood risk stays the same all the time – despite clear evidence that it doesn’t.

We analysed historical flooding data from ten major catchments in South East Queensland. As we report in the Australasian Journal of Water Resources, 80% of significant floods arrived during five-year windows, with 35-year gaps of relative dryness between.




Read more:
Old floods show Brisbane’s next big wet might be closer than we think


The early 1970s brought a succession of severe floods to South East Queensland. This was followed in the 1980s by a raft of floodplain development projects, together with extensive research on floodplains and flooding risk, carried out by a group of researchers who described themselves as the “Roadshow” because of their frequent visits to flood-prone regions.

Throughout the 1980s, some Roadshow members noticed that large floods in South East Queensland seemed to follow a 40-year cycle, with five-year periods of high flood risk separated by 35 years of lower flood risk. They speculated that the next “1974 flood” (a reference to a devastating flood that hit Brisbane and South East Queensland that year) would arrive some time around 2013 .

Sure enough, South East Queensland was once again hit by large floods in January 2011 and January 2013.

Evidently, large floods in South East Queensland are not random. This is a problem, given that development policies and engineering practice, by and large, still assume that they are.

History repeating

In 1931, the Queensland meteorologist and farmer Inigo Jones linked the Brisbane River’s floods to the Bruckner Cycle of solar activity, which he determined to be 35 years long, but which has since been found to vary from 35 to 45 years.

In 1972, flood engineer John Ward argued that flood frequency distributions differ in space and time because higher flows originate from a variety of different rainfall mechanisms. At the time, minimal insight was available into what those different rainfall mechanisms were.

In the 1990s, drought research in Queensland by, among others, researchers Roger Stone and Ken Brook and John Carter identified cyclical variations in Queensland rainfall associated with the Southern Oscillation Index (SOI), supporting the idea of non-random occurrence of floods.

In 1999, Australian hydrologist Robert French also noticed that irregular clustering of flood events was associated with the SOI, and pointed out that flood planning needed to take into account more than just seasonal or year to year variability.

More recently, flood incidence has been strongly linked to large-scale ocean processes such as the El Niño/Southern Oscillation (ENSO) and the Interdecadal Pacific Oscillation (IPO). These phenomena seem to have a marked effect on eastern Australian rainfall variability, and therefore on the risk of both floods and drought.

Is the 40-year cycle real?

We compiled records of major floods in South East Queensland between 1890 and 2014. As the table below shows, roughly 80% of large historical floods happened within a series of five-year flood-prone periods, despite these periods together representing only 16% of the study period.

The South East Queensland study area (approximately indicated by the orange box) and the 10 catchments analysed in this study.

Timing of the largest flood events within the 40-year cycles. Superscripts next to each flood event indicate the ranking of that flood event in that catchment (that is, the largest flood in each catchment is ranked 1).

On average, the number of large floods per year was 4.9 times higher within the five-year flood-prone periods.

Not only were floods more frequent, they were also more severe, with flood heights 41% higher during the five-year flood-prone periods than at other times.

Even though a few large floods occurred outside the five-year flood-prone periods, the 40-year cycle of flooding in South East Queensland appears to be a genuine phenomenon.

What drives the cycle?

The most likely physical explanation for cyclic or non-random flooding is the IPO, which is rather like the ENSO cycle except on longer time scales. The IPO influences eastern Australia’s climate indirectly, by affecting both the magnitude and frequency of ENSO impacts.

Recent “negative phases” of the IPO – meaning warmer than average Pacific Ocean temperatures north and south of the tropics – happened roughly during 1870–95, 1945-76, and 1999–present.

If we compare these with the five-year flood-prone periods in the table above, we can see that with the exception of 1930–34, all five-year flood-prone periods happened during these negative IPO events. Interestingly, the large floods in the 1950s and 1960s happened outside the five-year flood-prone periods identified by the 1980s Roadshow, but do align with IPO negative conditions.




Read more:
Planning for a rainy day: there’s still lots to learn about Australia’s flood patterns


In spite of all this evidence, most engineers and flood planners still assume that floods occur randomly and that flood risk is the same all the time. Phrases like “one in 100-year event” or “1% annual exceedance probability” are routinely used to describe floods, despite the fact that for some years and decades the risk is significantly higher. This gives a false sense of security during times when major floods are much more likely.

If this approach continues, then every few decades our flood defences will not be as reliable as we thought – a fact to which many Queenslanders can now attest.

We need new approaches to deal with the reality that large flood events do not occur randomly. It would arguably be more sensible to separate flood records into two (or more) categories – one for times when flood risk is “normal” and another for periods where the risk is higher – and then reevaluate flood frequency distributions and flood risks for each category. Decision makers then get a more realistic estimate of the true risk of flooding which leads to more informed and more resilient flood planning and defences.

This new approach might also help plan for the changes to flood risk expected in the future, whether from climate change, land use change, or whatever else the oceans and skies throw at us.


The ConversationThis article was coauthored by Greg McMahon, a Brisbane-based independent consultant on flood risks and Academic Chair at Rhodes Group Australia.

Anthony Kiem, Associate Professor – Hydroclimatology, University of Newcastle

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