Travertine pavements ‘stop floods’
– Cities could reduce flooding by constructing pavements from an absorbent building material commonly used in kitchens, scientists have discovered.
Pavements made from travertine – a form of limestone used for tiles and kitchen bench tops – can cut flooding by up to 50%, according to a study by researchers at Xi’an Jiaotong-Liverpool University in Suzhou, southeast China.
As well as helping water escape into the ground, travertine removes a number of pollutants that occur when rainwater mixes with dirt, rendering it suitable for agriculture, they said.
“We have more evidence to show that flooding is happening more often all over the world due to climate change,” said Xiaonan Tang, a co-author of the study and associate professor at the university. “This new material helps reduce urban surface flow to reduce flooding,” he said yesterday.
Over the past four decades, natural disasters have cost the Asia-Pacific region about $1.3 trillion (R19 trillion), according to United Nations (UN) estimates.
As the region’s population becomes more urban and the effects of climate change cause more extreme weather conditions, exposure to flooding is increasing, UN experts say.
Flood-prone cities such as Wuhan, in China, are increasingly testing new innovations to reduce risks. The metropolis has dubbed itself “sponge city” and turned to water-absorbing asphalt, among other measures.
Travertine is cheaper than both water-absorbing asphalt and concrete, and is found in volcanic areas around the world, but it has yet to be tested to determine whether it is strong enough to be used for roads, the researchers said. Traditional materials like concrete are not very absorbent, which exacerbates flooding.
“Travertine is a porous material with many tiny holes in it and those holes decrease its economic value in the current market,” said Hamidreza Rahimi, the report’s lead author. “In its holey form, it’s considered waste material as it needs to be smooth and holefree for home building projects.” –