May 2014 Floods in Serbia

Marina Babić Mladenović1, Vasiljka Kolarov1

 

 

 

1 Jaroslav Černi Institute for the Development of Water Resources, 80 Jaroslav Černi St., 11223 Belgrade, Serbia; E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it , This e-mail address is being protected from spambots. You need JavaScript enabled to view it

 

 

Abstract

In the middle of May 2014, a low-pressure area "Yvette" affected a large area of South-eastern and Central Europe. Some parts of the most affected countries, Serbia, Bosnia and Herzegovina and eastern Croatia, experienced three-months' worth of rain in just three days. Since the soil was already saturated due to intensive rainfalls in April and the beginning of May, the later event caused flash floods, erosion and landslides along small watercourses, but also disastrous flooding on the right tributaries and the main course of the Sava River. The flooding and landslides caused loss of human lives and a significant amount of damage, especially to housing, economic activities and infrastructure. While the damage assessment took place immediately after the flooding, the analysis of the flood patterns in Serbia is still ongoing. This paper gives a description of the source of flooding, which was intense precipitation, of the current state of the analysis of the affected areas during the flooding events which took place in the middle of May 2014 on the territory of the Republic of Serbia, and of the follow up activities triggered by this extreme situation..

Keywords: Floods, Маy 2014, Serbia.

 

 

Source of Flood

A low pressure system, named Yvette, developed over the Adriatic Sea on May 13, as polar air from Central Europe penetrated into the Mediterranean basin. The cold polar air mass met with humid subtropical air, leading to very low pressure. Meteorologists often describe this weather phenomenon as a Genoa Cyclogenesis. In May 2014, the centre of the cyclone moved from the Genoa Bay over the Apennines, Southern Adriatic, south of Serbia, Bulgaria and Romania. The most common path that Genoa cyclones follow is in the direction of the Black Sea, where they usually finally diminish (Nišavić et al, 2014). In this case, Yvette had departed from the usual path and made an elliptic loop over the south-eastern part of the Pannonian Plain. The cyclone moved very slowly (Figure 1), generating extremely high precipitation rates over Southeast Europe and the Eastern Alpine Region.

The highest amount of rain was recorded in the period 14-16 May 2014. Western and central parts of Serbia were the most affected, with three-day precipitation exceeding the average values for the month of May. Parts of the Drina and the Kolubara river basins were affected by rainfall which exceeded 1000-year three-day rains (Figure 2). The situation was additionally aggravated due to extreme soil moisture (Figure 3), which was a consequence of rainfalls in April and the beginning of May.

Serbia's river network is dense, with thousands of small torrential streams in the hilly and mountainous parts of the country, numerous rivers of various sizes, and several major lowland rivers.

Torrential streams are generally not trained or there are only local structural flood defences in place. Although flash floods affect smaller areas of land than large river floods, they pose a considerable danger and sometimes lead to human casualties. This is a consequence of their rapid onset (which limits the warning and response time), high flow velocity, and transport of river sediment and debris.

Due to the high intensity of rainfall that affected large areas and because the ground was already saturated by previous rainfall events, in May 2014 the floods on nearly all rivers in western and central Serbia were torrential in nature.

The heavy rainfalls triggered an almost immediate reaction of the smaller river basins. The first to swell were small torrential rivers in western Serbia, which registered extremely high flow velocities and large-scale sediment transport. The most notable example was the flood in Krupanj, which was flooded by several small torrential streams in a very short time; the trained sections of the channels were ruined and covered with enormous amounts of sediment, while many landslides were activated.