According to catastrophe modeling firm AIR Worldwide, Southeast Europe is experiencing record levels of flooding after three months’ worth of rain fell in just three days. The report cited the “many landslides” that have covered roads, homes, and villages, as well as knocking out bridges and blocking railways. “Many communities are cut off, keeping rescue boats and helicopters busy,” AIR said.
“On Tuesday, May 13, a low pressure system, named Tamara in Serbia, developed over northern Italy. During the next three days Tamara intensified and shifted towards the northern Balkan region. Tamara moved very slowly and intensified with moist warm air masses from the Black Sea.
“On May 15-16 Tamara turned into a steady-state, self-contained low-pressure system that generated extreme high precipitation rates over Southeast Europe and the Eastern Alpine Region. Meteorologists often describe this weather phenomenon as a Genoa Cyclogenesis with a Vb-track (pronounced “five-b-track”). Generally, low pressure systems with a Vb-track cause heavy floods in Central Europe.
“Due to an intense high pressure system on the west-northwest flank of Tamara, a high pressure gradient occurred and caused very high wind gusts in southern Poland, the eastern Czech Republic, and in eastern Austria, with maximum wind speeds up to 150 km/h [93 mph] in exposed regions.”
Bosnia and Herzegovina, Serbia, Croatia, Romania, Slovenia, Hungary, Austria, Slovakia, Czech Republic and Poland were among the countries impacted, according to AIR’s report. “Particularly heavy rain and snowfall was reported in Bosnia and Herzegovina, Serbia, and Croatia. In Bosnia and Herzegovina rainfall was the heaviest since records began in 1894. In the area around the Serbian capital, Belgrade, about 180 mm was measured within 48 hours.”
The report also pointed out that “northern Serbia is mostly lowlands and is a highly agricultural region that has experienced severe floods in the past. Most Serbian rivers drain to the Danube River, and floods along the Danube, which usually originate to the north of Serbia, affect many Serbian cities. One of the regions of Serbia most severely affected by Tamara is the drainage area around the rivers Sava and Drina.”
In addition AIR said: “Almost a third of Bosnia is flooded, principally in the north east of the country, affecting about a quarter of the country’s population. The worst flood was reported in the capital Sarajevo and Tuzla regions, in the center of the country, as well as the cities of Goražde and Bijeljina. Large parts of eastern Croatia are underwater, with several villages cut off. Casualties and power outages have also been reported in Poland, Slovakia, and Romania.”
According to AIR, in Southeast Europe, construction materials and the level of engineering required for flood resistance, “vary significantly depending on the occupancy class and location. Residential buildings are typically not as well engineered as commercial ones, and contents on the lower stories and cellar are usually quite different from contents in a commercial establishment.
“Many single-family residences are one-story buildings, the majority of which are masonry. When low-rise buildings such as these are flooded a significant percentage of the building, and its contents, can sustain damage, increasing the damage ratio. The presence of a cellar also increases the risk for contents damage.”
According to AIR, unlike single-family or small multi-family houses, “large apartment and condominium buildings frequently receive a degree of engineering attention similar to that given to commercial construction. The commercial building stock uses a wider variety of construction materials than residential buildings. Smaller office buildings, hotels, and other smaller commercial structures are usually masonry or reinforced concrete but larger buildings are almost exclusively made of reinforced concrete. Light metal and steel structures are typically used for warehouses and other low-rise storage buildings.”
In Serbia alone the area at risk of flooding covers about 1.6 million hectares [3.952 million acres] and includes over 500 larger settlements, and more than 500 large commercial buildings. “Across the region, the agricultural sector, on which the economy is reliant, is expected to be significantly impacted.
AIR also reported that over 24,000 people in Serbia “have been evacuated so far from the affected areas and over 26,000 households are without electricity. Officials have not yet released estimates of the damage caused by the floods, but they are expected to be high. According to AIR, the catastrophe insurance market in the region is currently limited and insurance penetration is low.
“The rainfall eased on Sunday, and some flood waters have receded, but the flooding is far from over. Water levels, particularly downstream, are likely to continue rising for some days and in some regions flooding may get worse. In the area of Sabac city for example, west of Belgrade, the Sava River has been contained thanks to extensive sandbag barriers, but if its waters rise another 0.2 meters [7.8 inches] they will overflow. Belgrade itself lies at the confluence of the Sava and Danube, and the flood level there is expected to rise through Thursday.
“Long-term forecasts suggest continued cycles of heavy rain throughout May. In areas where the flood risk is abating, it will be some time before flood waters have receded and much longer still before economic activity recovers.
Source: AIR Worldwide