Texas floods - Expert comment

Dr Jess Neumann, University of Reading, said:

"The devastating floods of Kerr County in Texas is a tragic reminder of the dangers of sudden extreme rainfall and flash flooding. 

"Flash floods are not uncommon in the Hill Country area of Texas, where the weather is easily influenced by a ready supply of moist air from the Gulf of Mexico. When very heavy rain falls on steep hillsides, this can create the conditions for raging torrents to be created in previously dry river beds, in just a matter of hours. 

"Totals of 200mm (around 8 inches) of rainfall were originally forecast, which is a significant amount in any location. In places, this is expected to have reached more than 12 inches of rain. For context, in the UK, 50mm of rain a day is considered heavy rainfall with serious potential for flooding. 

"This terrible event, in which children are missing and many have died, raises critical questions about effective early warning systems, flood planning and preparedness in the region. 

"It cannot be right that a flood of this magnitude, in an area known to be at high risk of flash floods, caused such devastation and has taken so many people by surprise."

Professor Hannah Cloke, professor of hydrology at the University of Reading, said: 

"For so many children to be swept away in a flood is an almost unimaginable horror. Sadly, it can be the inability to see such a tragedy emerging that can be part of the failure of an early warning system for floods. An alert system is a chain of human communication, and if one person in any part of the chain doesn't respond as they should to take action, the system runs the risk of failure. Human communication about events that have not yet occurred requires the use of imagination, and a lack of imagination can be lethal.

"This downpour seems to have been well forecasted by multiple forecasters around the world, several hours in advance. Warnings were issued, but the systems do not seem to have been in place to get information to those in harm's way fast enough. The timing of the flood, which happened in the middle of the night, would have meant that any last-minute actions to get out of the way of the water would have been hampered by darkness. 

"It is not good enough for authorities to say they were not aware that floods were coming. Warnings were available but the message just didn't get through. This must be a reminder of the need to invest more effort in checking every aspect of early warning systems, from the science, to the communications, to the education required to spread more understanding of the risks and how to respond to them.

"Once again, we are left horrified and humbled by the dreadful power of the weather and the ability of our rivers to take lives."