5 july 2013

How will Europe prepare for the next flood?

Erica Rex, E&E Europe Correspondent, July 5, 2013

German officials reacted with alarm when they found themselves not quite prepared last month for the worst flooding in 400 years. In mid-June, during the third week of the deluge, Germany found itself short of sandbags. Its neighbors -- the Netherlands, Luxembourg, Belgium and Denmark -- quickly came to Germany's aid and provided 1.65 million empty sandbags.

According to a report in Der Spiegel, government sources would only talk about the crisis on condition of anonymity, as this kind of shortfall -- call it poor planning or being caught out by an act of God -- had simply never happened before. In Austria, more rain fell the last days of May and first of June than usually falls in two months. According to the U.S. National Oceanic and Atmospheric Administration's National Climatic Data Center, May 2013 was the third-warmest May since record-keeping began in 1880.

The widespread flooding of the past month in Germany, Austria, Switzerland, and parts of Hungary and the Czech Republic has been some of the worst in history. The situation was so dire in some places, German local governments had to resort to extreme measures.

On the Elbe River near the village of Fishbeck, in the state of Saxony-Anhalt, officials exploded and sank three barges in order to repair a breached levee. Last week, officials reported the dam was 80 percent restored, and water had ceased to flow onto open land.

Although the flood tide is ebbing, more than 50 square miles of surrounding area remains underwater. Yet as water levels return to normal, the price tag for the disaster continues to rise. Risk modeling firm AIR Worldwide, part of the Verisk Analytics Group in Boston, estimates the flooding in Germany alone will cost insurers between $5.4 billion and $7.8 billion.

Andreas Krosta, head of group communications for the Talanx Group, which owns Hannover Re Group, the world's largest reinsurer, said its own loss estimate of $328 million is on the low side. The Allianz Group estimates its losses will be in the neighborhood of $394 million. The total cost, according to an estimate by insurance broker Aon Benfield, could be around $22 billion, including losses to individuals, businesses, municipalities and governments.

Causes and effects

The climatic conditions that caused the recent flooding can be attributed to a low-pressure weather system that remained stuck north of the Alps for several days, resulting in an inordinately concentrated single torrential downpour. Stuck weather systems are responsible for other extreme weather conditions, such as the European heat wave of 2003. That event was caused by the inverse condition: a high-pressure area that remained stuck over most of Western Europe for several days.

Stuck weather systems, known as "blocking events," result when one of the jet streams -- air currents that whisk around the Earth's upper troposphere 4.3 to 12 miles up -- pinches off large air masses from the normal wind flow for an extended period of time. These pinches or kinks last for several days, sometimes for weeks, and cause weather patterns simply to stall, resulting in floods, heat waves, droughts and blizzards.

NASA Goddard Space Flight Center oceanographer Sirpa Häkkinen and her team analyzed atmospheric data from the 20th century and found that blocking events now occur about 30 percent more often than they did during most of the last millennium. Since the 1990s, the trend has been upward.

The frequency of blocking events also corresponds with those periods when the surface temperature of the North Atlantic Ocean is higher than it has been historically. The overall temperature of the ocean's surface is higher now than it's ever been.

None of this bodes well, either for the grim reality of extreme weather conditions -- which are likely to continue and increase in frequency, as are their human and economic consequences -- or for the ocean itself. Clusters of blocking events can actually speed up or slow down circulating ocean currents, called "gyres" in the North Atlantic. A slower, weaker gyre allows warmer water from nearer the equator, which is normally trapped in the gyre's whirlpool, to slip northward, eventually eroding glaciers and contributing to the melting of the Greenland ice sheet.

"This trend is going to last for a while," Häkkinen said, "unless something changes drastically. I don't know what that's going to be, though."

Warning system never made it to flood-ravaged towns

Information disasters compound terrestrial disasters. Some disasters can be averted by building better dams or by building diversions to manage high water, like those built by the German city of Dresden on the Elbe after the 2002 floods. But weather patterns brought by long-term climate change can't be as quickly or easily undone.

Part of what will make new disasters less dire, despite their increasing frequency, comes down both to preparedness and communication, said Ulrich Meissen, a scientist at the Fraunhofer Institute for Open Communication Systems (FOKUS) in Berlin. Since the end of the Cold War, when the disaster siren infrastructure in Germany was jettisoned, there has been no comprehensive public warning system to speak of.

Meissen's group set out to remedy this, introducing a system called WIND (Weather Information on Demand), an extreme weather warning system, in 2002. Users subscribe to the system, which they can configure themselves online. They can opt to receive local weather alerts via text message, fax or email, specifying a location according to postal code, county or geo-coordinates.

Since that time, the scope of some disasters, as well as the needs of the population, has changed. Meissen currently heads up a project known as Electronic Safety and Security Systems for the Public and Industries (ESPRI), which has developed localized texting technology to provide warnings for all kinds of disasters, both natural and man-made.

"Each person should have access to a message containing the right information," Meissen said. "Warnings will be tailored to cities as well as to precise geo-locations for users." Subscribers can receive warnings on their mobile devices, via text or email.

The system, called KATWARN, provides timely warnings as well as advice on how people should behave, tailored to their postal code. KATWARN can be used for non-weather-related disasters, such as fires or, as has happened in more than one instance, an unexploded World War II-era bomb.

The system, which was introduced in 2011, has more than 1 million subscribers in Europe. Although its installation price tag, which local councils must foot, is hefty -- €15,000 ($19,500) along with an annual subscription charge and small per-message fee -- follow-up technical assistance, infrastructure upgrades, and the cost of operations and research and development are provided by regional public-sector insurers.

Unfortunately, none of the localities most seriously harmed by this year's European floods was hooked up. Only 14 German municipalities have adopted it thus far, including districts in Hamburg, Nürnberg and Munich.

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