Spatiotemporal Review of the Torrential Flood Phenomenon in the Morava River Basin
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SPATIUM UDC 556.166(282.243.744) No. 34, December 2015, pp. 64-69 Review paper DOI: 10.2298/SPAT1534064P SPATIOTEMPORAL REVIEW OF THE TORRENTIAL FLOOD PHENOMENON IN THE MORAVA RIVER BASIN Ana M. Petrović1 Ratko Ristić, Faculty of Forestry of the Belgrade University, Belgrade, Serbia , Geographical Institute “Jovan Cvijić” of the Serbian Academy of Sciences and Arts, Belgrade, Serbia Phenomenon of torrential floods as the most destructive and the most frequent natural hazards in Serbia with serious socioeconomic, cultural and environmental consequences deserve special attention. In this paper, data collection strategy and data analysis with the aim of spatiotemporal characterization of the torrential flood phenomenon in the largest national, Morava river basin, are presented. A dataset (derived from the Inventory of torrential floods in Serbia) of 479 registered torrential flood events with over 84 casualties for the period 1926-2013 is presented. Monthly distribution of registered torrential floods indicates that the majority of events with the highest share of death toll occurred in the late spring, from May to the end of June. According to the annual distribution there is a linear increase of torrential flood occurrence in the course of 88 years, but decrease of death toll is found. The greatest number of torrential flood events and casualties is registered in the Južna Morava river basin (watersheds of Nišava, Toplica, Veternica, Jablanica). The results of this work can be of great value in the implementation of the Flood Directive of the European Commission on a river basin level as well as for the future natural hazards information system in Serbia. Key words: torrential floods, spatiotemporal distribution, Zapadna Morava, Južna Morava, Velika Morava. INTRODUCTION Torrent network at the territory of Serbia numbers more than 12000 torrents (Kostadinov et al., 2006), mostly phenomenon have made many countries in the world suffer The frequency and magnitude of the torrential flood Morava river basins due to relief dissection as well as extent the large human and economic losses in the recent period situated in the Južna Morava, Zapadna Morava and Velika (Hershy, 2005; Münchener Rückversicherungs-Gesellschaft, 2009; Marchi et al., 2010; Gourley et al. 2010, Shao et al., of area. The most striking torrential flood in the course of 2014; Wang et al., 2015; Abbas et al the 80ies occurred in Lještarska dolina (Južna Morava, July are the frequently reccuring water-related natural hazard in 1982), Sejanička (Južna Morava, July 1983), Lugomir (Velika ., 2015). Torrentialet al., 2011a; floods inMorava, studied February river basins 1986) happened and Vlasina in watersheds (Južna Morava, of Lugomir, June et al., et al., 2013; Kostadinov 1988) watersheds. Recent large-scale torrential flood events etSerbia al., 2014).that deserves This kind a special of natural attention hazard (Ristić is related to the Dragićević 2011; Dragićević hilly-mountainous regions in Serbia, on the territory south Gruža, Jasenica and Lepenica in July 1999 (Velika Morava, of the Sava River and the Danube River, endangered by eight fatalities), Resava in June 2002 (Južna Morava, one intensive soil erosion processes, having as a consequence death), Vlasina in November 2007 (Južna Morava). Although the extreme flood events in April and May 2014 occurred mainly in north-western part of Serbia, flood events in specific hydrological and sediment transport regime in the noticed material damages. occurs after a short-duration heavy rainfall as a sudden Jagodina, Požega and Lučani in the Morava river basin left appearancetorrential riverbeds of maximal (Petrović, discharge 2014). with Torrential a high concentration flood wave of erosion sediment lasting from one to several hours events in Serbia were analysed, mostly they are poorly et al., 2012; Garambois et al., 2014). Torrential documentedHowever, a smalland mainly number described of historical with some torrential photos flood and rare measured data. Although population and local economy mean(Ristić discharge having destructive energy. However, these extremesflood wave are discharge mostly ungauged can be larger despite than the 1000 need times of special than basin, there was no centralized and consistent collection kind of surveying (Borga et al., 2008). is highly affected by torrential floods in the Morava river in several developed countries which contribute to better 1 of data on torrential floods. Databases on natural hazards [email protected] Đure Jakšića 9, 11000 Belgrade, Serbia understanding of torrential floods as extreme hydrological 64 spatium Petrović M. A., Ristić R. : Spatiotemporal review of the torrential flood phenomenon in the Morava river basin hazards, records this phenomenon for the past several studies with detailed analysis of past events. Absence of centuries (Swiss database on natural hazards numbers data and reports on torrential events in archives of public over 20,000 events; Austrian database on natural hazards organizations on the state and local level mainly impeded numbers about 28,000 events, of which torrent events share them to contribute to this dataset. Method for building th century) et al., 2014). The purpose of this work is to present spatial and time framework and needed parameters, after is over 20000; the first record is situated in the 6 the insightsdataset consistsinto data of availability, five important (2) datasteps: collection, (1) defining (3) basin(Petrović through spatiotemporal characterization of historical organizing data, (4) data analysis, (5) data publishing, a phenomenon of torrential floods in the Morava river et al., 2015). Collection of intorrential accordance flood with events the Europeanin order to Union give Floodcontribution Directive. to the Tabledistribution 1) facilitated and use (Petrovićanalysis of spatial and temporal improvement of the torrential flood policy which should be minimum data (as shown in an example of river Koritnička, METHODOLOGY basin. The research question of data analysis consists in examiningdistribution the of torrentialtrend changes flood eventsof frequency in the Moravaof torrential river Study area The research focus is on the greatest “national” river basin localities with material damages and casualties. in Serbia (Figure 1), which is mostly hilly-mountainous area, flood occurrence as well as in exploring the most frequent Table 1. An example of minimum data for registering torrential flood event the Serbian territory and homes of 53% of population are situatedwith the within.confluence According to the Danubeto the Water River. Management It covers 41.5 Plan % of river basin (A=15,465 km2), 19,110 ha in the Zapadna Moravathe Republic river of basin Serbia (A=14,653 (2001), 38,890 km2) haand in 26,400the Južna ha Morava in the Velika Morava river basin (A=6,810 km2) are potentially meteorological extremes, geological and soil properties flooded area of a return period of 100 years. Beside changes and topography are the direct factors of torrential regimesunfavourable of water for waterdischarges, infiltration, i.e. disbalanced deforestation, ratio betweenland use high and low waters in watersheds of torrential tributaries in the Morava river basin. meteorological (rainfall quantity and duration), hydrological (dischargeRare torrential and waterflood level)events and were sediment recorded transport with data.full Mainly they are modestly documented. For example, in the case of information about an affected location, but not the intorrent, scale 1:25,000for identification (printed ofby micro-torrential Military Geographic catchment Institute, as 1980)a subject for ofthe flood whole event, area geo-referenced of the Morava topographic river basin mapswere used. Therefore, affected locations are given geographic coordinates in this database becoming geospatial data on natural hazards. RESULTS river basin dates from the sixteenth century and refers to the One of the oldest records of torrential flood events in studiedth floodfound of in the monastery Raška river chronicles (Zapadna dating Morava from river XVIII basin) and on 18XIX centuryMay in 1518 representing (Šakota, introductory1989). Some historicalflood descriptions information were of Figure 1. Study area – Morava river basin this dataset. Dataset consists of data on the torrential floods Materials and methods during XX century up to date. The first data in the previous incentury “torrential” we avail 1929 is the in May,torrential June andflood August. of the Skrapež in May 1926. The following 20 torrential flood events were located river basin is derived from newspaper articles gathered The dataset of torrential flood events in the Velika Morava 479 events with over 84 casualties for the period 1926-2013. (1975), archival documentation of the newspaper “Politics” Dataset on torrential floods in the Morava river basin records for the periodperiod fromfrom 19701926 toto 20131970 andin the data book from by papers Gavrilović and The largest number of torrential flood events and casualties took place in the Južna Morava river basin (Figure 2) which spatium 65 Petrović M. A., Ristić R. : Spatiotemporal review of the torrential flood phenomenon in the Morava river basin is a result of an inadequate soil management, extreme forest exploitation and destruction and intensive soil theoretical probability function is given in this work for erosion processes (i.e. inadequate watershed management) Hydrological statistical analysis according to the most fitted