<
https://theconversation.com/the-extreme-floods-which-devastated-spain-are-hitting-more-often-is-australia-ready-for-the-next-one-242686>
"Spain is still reeling from recent floods in the Valencia region. In some
areas, a year’s worth of rain fell in a single day. Sudden torrents raced
through towns and cities. Over 200 people are dead. Rapid analysis suggests
daily rainfall extremes in this region and season have become twice as common
over the last 75 years and become 12% more intense.
The World Meteorological Organisation has pointed out that climate change is
steadily increasing the risk of extreme floods like these. Warmer air can hold
more water vapour, about 7% more per degree Celsius of warming. More moisture
generally leads to more intense rainfall, and therefore more extreme floods.
The physics of how temperature influences the atmosphere’s capacity to hold
moisture has been known for close to 200 years. But we’ve learned something
worrying more recently. When water vapour condenses to form rain droplets, it
releases heat which can fuel stronger convection and boost updrafts of air
currents in storms. This means the intensity of extreme rainfall could increase
not just 7% per degree of warming, but over twice that rate.
Last week, CSIRO and the Australian Bureau of Meteorology released their
biennial report on the
State of the Climate, which found “heavy short-term
rainfall events are becoming more intense”. Australia, the report states, has
already warmed 1.5°C since national records began in 1910. In recent years,
extreme rains have triggered devastating floods in New South Wales and
Queensland.
The question now is – are we prepared for these more damaging floods? This
year, Australia updated the climate change section of Australia’s flood design
guidance. But while this will help ensure that future infrastructure is better
able to weather extreme floods, our current bridges, roads and stormwater
drains have not been built to weather these increases in extreme rainfall.
Similarly, our flood planning levels – used to determine where houses, offices,
hospitals and so forth can be built – have generally not factored in the
reality of the threat."
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
