Intense rains that triggered floods in Italy may become more common

Image Credit: Patrick Feller.

Rainfall intensity has increased over the past 120 years in Italy’s northern regions according to scientists at the Institute of Atmospheric Sciences and Climate in Bologna, Italy.

The torrential rains that triggered flash flooding and mudslides in northern Italy during October 2011 were unusual but not completely unexpected according to research performed by scientists at the Institute of Atmospheric Sciences and Climate in Bologna, Italy.

The floods in Italy destroyed many buildings and took the lives of at least nine people. Coastal areas near Liguria and Tuscany were particularly hit hard by the heavy rains and Italy has declared a state of emergency for regions damaged by flood waters. On November 3, 2011 emergency management officials evacuated the town of Vernazza in anticipation of more heavy rains to come.

Flood damage in Liguria, Italy. Image Credit: Miriam Rossignoli.

Dave Petley is a professor in the Department of Geography at Durham University in the United Kingdom and author of The Landslide Blog. In a recent post, he noted that rains in northern Italy reached an intensity of over 140 millimeters per hour (6 inches per hour) on October 25, 2011. Rainfall intensities greater than 140 millimeters per hour are unusual and rarely seen outside of hurricane and tropical cyclone conditions.

A research team led by Michele Brunetti at the Institute of Atmospheric Sciences and Climate in Bologna, Italy analyzed trends in rainfall across Italy in a 2004 paper published in the Journal of Geophysical Research. The scientists observed that from 1880 to 2002 Italy has become somewhat drier as indicated by a decline in the number of wet days that occur annually. However, precipitation intensity has increased over the past 120 years in Italy’s northern regions. These data suggest that northern Italy may be in for more frequent extreme weather events in the future.

Italy has some of the longest-running meteorological records in the world. Many cities in Italy such as Bologna, Milan and Rome began collecting meteorological data back in the 1700s. Long-term meteorological datasets are valuable tools that help us to understand our changing climate.

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France hit by storms in south, three dead

PARIS | Sun Nov 6, 2011 12:07pm EST

(Reuters) - Heavy rains and flooding in southern France over the weekend forced the evacuation of about six hundred people, and three people died in weather-related deaths as a dozen local regions remained on alert on Sunday.

Rivers overran their banks, flooding streets and homes and leaving hundreds stranded. Television images showed cars floating along roads and residents mopping up their sodden, muddy homes.

A retired couple, both aged 71, in the southeastern coastal town of Bagnols en Foret died late Saturday night or Sunday morning from carbon monoxide poisoning while trying to bail out rising water in their cellar, police said.

On Saturday, police told Reuters they found the body of a 51-year-old homeless man who had been washed away from his campsite in the Herault southern region.

Some 600 people have already been evacuated along the coast and in the Alps in the south east of the country, authorities said. Firefighters helped rescue around 1,200 people affected by the storms, using helicopters to save about 30 people.

An orange alert -- the second-highest weather alert after red -- remained in place in 12 southern regions on Sunday, down from about 16 on Saturday.

The regions affected are the low-lying areas near the Pyrenees in the south west, where it continued to rain on Sunday, and in the flooded Alps region.

In the past two days, the level of the Var river in the southeast rose from 1.5 meters (4.9 feet) to 5 meters, said Europe 1 radio.

Elsewhere in Europe, at least seven people were killed in Genoa on Friday as torrential flooding hit the city following days of heavy storms which killed at least 10 people in northern and central Italian regions.www.reuters.com

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