J & S Franklin Ltd2018-05-22 09:18:47
Stark Warnings of the Need for Global Flood Protection
So far this year, we have read UCLA research forecasting a severe climate future for California, with suggestions that we may be looking at “The Other Big One”, the UN Economic & Social Commission for Asia and the Pacific (ESCAP) projecting that disasters could cost the Asia Pacific Region £160 billion per year by 2030, and Potsdam Institute for Climate Impact Research issuing an urgent call for more flood protection from river floods around the world under future global warming.
When such renowned bodies like these issue stark warnings of damage to infrastructure, to habitation and life itself, surely governments and authorities around the world should look at increasing their flood protection levels.
It is suggested that rainfall changes caused by global warming will increase river flood risks across the globe. Already today, fluvial floods are among the most common and devastating natural disasters. Scientists have now calculated the required increase in flood protection until the 2040s worldwide, breaking it down to single regions and cities.
Lead-author Sven Willner from the Potsdam Institute for Climate Impact Research (PIK) says, “More than half of the United States must at least double their protection level within the next two decades if they want to avoid a dramatic increase in river flood risks.”
The PIK report states that without additional adaptation measures - such as enhancing dykes, improved river management, increasing building standards, or relocating settlements, the number of people affected by the worst 10 percent of all river flooding events will increase in many places: In Northern America from 0.1 to 1 million (while this seems not like a large number, it is a tenfold increase).
Absolute values are even bigger elsewhere: in South America the number of people affected by flooding risks will likely increase from 6 to 12 million, in Africa from 25 to 34 million, and in Asia from 70 to 156 million. The real numbers might be even higher in the future as population growth and further urbanisation is not considered.
“Without limiting human-caused global warming to well below 2 degrees Celsius, river flood risks in our century will increase in many regions to a level that we cannot adapt to,” says Anders Levermann, joint author of the PIK report “To keep people safe climate-change-induced risks must be taken seriously and money must be spent for adaptation. If we act now, we can protect against the risks of the next two decades. But further climate change must be limited by cutting greenhouse gas emissions from fossil fuels to avoid risks that surpass our abilities to adapt.”
In recently published research by UCLA climate scientists, the authors predict that the State of California will experience a much greater number of extremely wet and extremely dry weather seasons, especially wet, by the end of the century, and that will be a major increase in the likelihood of severe flooding events.
Daniel Swain a climate scientist at UCLA Institute of the Environment and Sustainability and the Nature Conservancy said, “Those who manage California’s water supply and protect residents from wildfires, floods and other natural disasters should be planning for those changes. Millions of lives, wildlife and the health of a multi-trillion-dollar economy depend on it.”
Swain and his fellow researchers, including professors David Neelin and Alex Hall of UCLA’s department of atmospheric and oceanic sciences, also found over the next 40 years, the state will be 300 to 400 percent more likely to have a prolonged storm sequence as severe as the one that caused a now-legendary California Great Flood of 1862 which filled valleys with feet of water and washed gold rush miners and their equipment out of the mountains. In the Central Valley, floodwaters stretched up to 300 miles long and as wide as 60 miles across
It could happen again, only with more catastrophic consequences because the state is so much more populated than it was then. In 1862, California’s population was 500,000; today, it’s close to 40 million.
“The findings should be a warning to decision-makers,” adds Levermann. “If they choose to ignore the issue, sadly enough disaster will come. The time has come where mitigating future climate change must be accompanied by adapting to the climate change that we already caused. Doing nothing will be dangerous.”
One product equipped for the challenge and proven in the US in a flood protection role is the DefenCell Flood Protection Wall.
Smithland, Kentucky, USA, is a town which is situated at the confluence of the Ohio and Cumberland Rivers. In 2011, it had to deal with a record surge in river levels. The Louisville Office of the U.S. Army Corp of Engineers (USACE) requested an emergency installation of a DefenCell Flood Wall system.
Within 24 hours, 3 miles worth of DefenCell Flood Wall units were delivered.
Within an hour of delivery, small teams were able to start placing, connecting and filling the systems.
After just two hours, installation was being achieved at a rate of 20+ units per hour, (Equivalent to 22,196 sand bags in the initial three hours after delivery.)
In 34 hours, more than 10,500 linear feet of DefenCell Flood Walls had been installed, over 700 units were filled with more than 4,700 tons of sand, by an untrained, local workforce. The barrier was more than one mile in length, adding an extra four foot of flood protection height to the Smithland levee.
The DefenCell Flood Wall is a non-metallic geotextile-based system, developed initially for ballistic defences in military operations. However, its versatility, flexibility and ability to contour to uneven ground surface with minimal preparation, combined with making angles and curves, being light weight and man portable, and the fact that it can be quickly constructed using local fill, sand and common aggregates, has shown it to be effective in a Flood protection and critical infrastructure protection roles.
The DefenCell Flood Wall and the alternative DefenCell MAC FE weldmesh gabion system have both been successfully tested as flood barriers by the US Army Corps of Engineers, Research & Development Center on the Mississippi in Vicksburg.
“People tend not to die in droughts in places with a developed economy,” Daniel Swain said. “People do still die in floods. It happened this year and last year in California.”
DefenCell is not the total solution to “The Other Big One”, but is could certainly go a long way to offering solutions to some of the need for Global Flood Protection.