Why are we seeing so many floods?
Floods are made more likely by the extreme weather conditions caused by long-term global climate change, including change in land cover — such as removal of vegetation — and increasing temperatures. Flooding from intense summer rainfall, like the ones seen recently in London this July, will become a more common occurrence as the climate crisis worsens, with floodplains in some countries being expected to grow by 45% by the end of the century.
There are four types of major floods:
● River flooding occurs when a river or stream overflows its natural banks and inundates normally dry land.
● Coastal flooding happens when winds from a coastal storm push a storm surge (a wall of water) from the ocean onto the land.
● Flash floods are caused by heavy rains over a short period (usually 6 hours or less) and can happen anywhere, although low-lying areas with poor drainage are particularly vulnerable.
● Urban flooding refers to flooding that happens when rainfall (not an overflowing body of water) overwhelms the local stormwater drainage capacity of a densely populated area.
In Germany and Belgium, record rainfall caused rivers to burst their banks leaving villages destroyed, bridges broken, and creating a death toll of over 100. In Belgium, a manslaughter investigation has been opened over the deaths of 38 citizens, with the investigating magistrate being tasked with identifying who might be responsible for “involuntary homicide by lack of foresight or precaution”.
In the U.S., coastal flooding has doubled in a matter of decades and in the Northeast, extreme storms generate approximately 27% more moisture than they did a century ago. Essentially, because of global warming, when it rains it pours more. Heavy precipitation is expected to increase throughout the 21st century to a level from anywhere between 50% to as much as three times the historical average. Another factor increasing the risk of flooding is the increase in snowmelt, with hotter temperatures triggering more rain-on-snow events and warmer rains inducing faster and often earlier melting.
Although governments have made commitments to reduce carbon emissions and implement greener policies, little has been done in the way of allocating much needed budgets on preventative measures against the increase of natural disasters and extreme weather conditions due to climate change.
To cope with these environmental pressures, an overhaul of UK and global infrastructure is urgently required to prevent further damage and loss of life. Buildings will need to be redesigned and public areas transformed to include better drainage channels and innovative ideas such as porous pavements. Some progress has been made with the UK government announcing that they will spend a record £5.25bn over the next six years on reducing flooding.
https://www.bbc.co.uk/news/world-europe-57858829
https://www.nrdc.org/stories/flooding-and-climate-change-everything-you-need-know
By: Claire Carlisle
