28 October 2011

The remarkable rainfall that caused the floods and landslides in Italy this week

Posted by Dave Petley

Summary: Rainfall records from Liguria this week suggest that peak rainfall intensities were truly exceptional – at one gauge they exceeded 140 mm per hour – leading to the flood and landslide disaster that affected northern Italy on Tuesday.

A couple of days ago I highlighted that northern Italy had suffered very heavy rainfall, inducing floods and landslides in particular in the Liguria and Tuscany regions.   Data on the rainfall at Brugnato in La Spezia, one of the worst affected areas, has been made available via the meteonetwork.it site:

 

http://forum.meteonetwork.it/meteorologia/138511-grave-alluvione-lampo-nel-levante-ligure.html

 

This is an extraordinary volume of rainfall, with total volume exceeding 500 mm and hourly intensities of more than 50 mm for five hours.  The maximum hourly intensity of over 140 mm is rarely seen outside of a tropical cyclone.  It is no wonder that the consequences were so serious.

The www.cittadellaspezia.com website has detailed coverage of the event (in Italian of course), including a gallery of images collected on the day:

 

http://www.cittadellaspezia.com/fotogallery/Alluvioni-e-frane-Le-immagini-del-561_1.aspx

 

And in the aftermath:

 

http://www.cittadellaspezia.com/fotogallery/Monterosso-le-foto-dell-apocalisse-564_1.aspx

The final death toll in this disaster is not known at present.