The Frequency of the Years in Which Big Waters and Floods

Review of Historical Geography and Toponomastics, vol. I, no.1, 2006, pp. 89-106 A HISTORY OF ABOUT 300 YEARS OF HIGH WATERS AND HYDROTECHNIC CONSTRUCTIONS IN BANAT (I) Martin OLARU ∗ West University of Timişoara, Department of Geography, Blv. V. Pârvan, No.4, 300223, Timişoara, Romania, e-mail: Abstract. This study is a synthesis on three centuries of hidrotechnical managements and high levels of rivers in Banat, including four distinct periods for the floodings which produced great damages: 1700-1876; 1877-1949; 1950-1972 and 1973-2005. It was also important the flooding from April 14th –30th 2005 in the hydrographical basin Timiş-Bega. Analyzing the frequency and the amplitude of the floodings in time, it can be concluded that these are in a continuous increase. The defend against floodings, the management and the dams, the whole history of the big hydrographical and navigation works could be grouped in the following stages: (a) From the beginning of the 18th century till the 1848-1849 Revolution; (b) From 1848-1849 Revolution till year 1871; (c) From 1871 till the First World War; (d) The Interwar period; (e) From the Second World War till 1989 Revolution; (f) 1990-2005. As in all EU countries which had to cope with floodings, in Banat as well it must be applied the new concept «more space for rivers», building dams at longer distances than the river banks. Rezumat. Lucrarea sintetizează cele trei secole de amenajări hidrotehnice şi ape mari din Banat, grupând în patru mari perioade distincte marile viituri, care au produs pagube însemnate locuitorilor acestei provincii istorice: 1700-1876; 1877-1949; 1950-1972 şi 1973-2005. Consemnăm pe lângă alte ape mari şi viitura din 14-30 aprilie 2005 din bazinul hidrografic Timiş-Bega. Analizând frecvenţa şi amplitudinea viiturilor în timp ajungem la concluzia că acestea sunt într-o continuă creştere. Apărarea împotriva inundaţiilor, amenajarea şi stăvilirea apelor, întreaga istorie a marilor lucrări hidrotehnice şi de navigaţie, o putem grupa în mai multe etape importante: (g) Începutul secolului al XVIII-lea până la Revoluţie de la 1848-1849; (h) De la Revoluţia de la 1848-1849 până la anul 1871; Martin OLARU (i) De la 1871 până la Primul Război Mondial; (j) Perioada interbelică ; (k) După cel de-al Doilea Război Mondial până la Revoluţia din 1989 (l) 1990-2005 Şi în Banat, ca în toate ţările Uniunii Europene confruntate şi ele cu mari inundaţii trebuie să aplicăm noua concepţie : « mai mult spaţiu pentru râuri », construind diguri la distanţe mai mari faţă de malurile râurilor. Key words: high waters, catastrophic floods, hystoric votes, hydrotechnic constructions, hydrotechnic node, cribbing channel, navigable channel. Cuvinte cheie : ape mari, inundaţii catastrofale, viituri istorice, amenajări hidrotehnice, nod hidrotehnic, canal de plutărit, canal navigabil Many speciality works record besides the historical data also information regarding certain extreme climatic or hydrographic phenomena: very low or very high waters. We will deal with the very high waters and their interception in time because they determined floods and huge damages, and the usage of the very low waters for different services of the water courses was very labouring. The hydrologic phenomena propagated at a certain periodicity were recorded in different ways. These data were found in old annals or charters, geographic descriptions, notations on old eclesiastic books by priests, in monographies, laic books or small memorialistics, communicated from generation to generation as special events kept in the mental of the site, where the catastrophes or big floods were recorded. Most of these floods brought loss of human lives, homesteads and whole villages, with hard to imagine damages mentioned in the documents of that time kept in archives, museums, private collections and historic literature. There are numerous historic references to the floods on the Danube beginning with the IVth century AD, then to those from Câmpia Tisei and East of Banat, the Xth century, to the rivers from Banat plain and Mureş starting with 1508 and to other rivers like Timiş, Bega in XVIIth century and the beginning of the XVIIIth century, and in the next century (the XIXth) to the rivers Caraş, Nera and Cerna. The most vulnerable area in Banat, constantly threatened by floods is the plain part, in the north and center of the Timiş Plain (Fig. 1). About the beginning of the hydrometric activities on the rivers from Timiş County and Banat we can mention that in the first stage – that starts from the second half of the XIXth century – there were set up 21 hydrometric stations at: „Făget (1875), Balinţ (1875) and Timişoara (1856), all of them on the river Bega; Podul Cenei (1888) on Bega Veche; Lugoj (1874) and Şag (1874) on Timiş; Partoş (1880) on Bârzava. Another important moment is the year 1919. Now, there were installed other 17 hydrometric stations on the connecting channels between rivers and small branches that functioned almost continuously until 1951-1952 when they were liquidated. In the first stage at the hydrometric stations are made only measurements of the water levels, and also is growing the hydrometric knowledge degree at a large number of stations on the main rivers from this part of the country. 90 A history of about 300 years of high watersand hydrotechnic constructions in Banat(I) After 1950 the hydrometric activity meets a qualitative and quantitative jump because in this period began the systematic and complete activities regarding the levels observations and volume measurements at the 29 stations in Banat1. Fig.1. The surface of the maximum floodable teritory in Banat (after A. Zănescu, 1974) In the period 1952-1962 at the 95 hydrometric stations were effectuated 4829 volume measurements, constituting a hydrometric data stock that covers the whole geographic area of Banat2. 1 Monografia hidrografică a râurilor din Banat, 1964, pp. 28-29 91 Martin OLARU After Alexandru Zănescu, specialist and hobbyist of these phenomena, we group the hydrologic information - on a period of over 270 years (1700-1972) -, characterized by data continuity (table nr. 1), - in three distinct periods: 1700-1876 period that comprises the possible informative data based on historic documents and recordings; 1877-1949 period that comprises the techno-relative part with empirical data, observations and high waters levels measurements; and 1950-1972 period, the certain technical-scientific stage with volumes and levels measurements3. The first period that extends on 176 years from which 67 are years with high waters and 161 floods; in the next 73 years, from the second period, 46 were years with floods, on all the rivers there were 129 high waters; and in the last period 1950-1972, from the 23 years, 22 were years with high waters and 144 levels that got beyond the floods marks (table nr. 1). Tabel 1. The frequency of the years when high waters and floods happened on the rivers from Banat (1700-1972) Probable data Periods ensemble Subjective certain data Objective certain data 1700-1876 1700-1972 River and years years years years frequency frequency frequency frequency basin period, with period, with period, with period, with of floods/ % of floods/ % of floods/ % of floods/ % years high years high years high years high years years years years waters waters waters waters Number of years with 67 1/2,6 38,1 46 1/1,6 63,0 22 1/1 95,5 135 1/2 49,6 high waters Mureş 40 1/4,4 22,7 12 1/4,9 20,6 17 1/1,4 73,9 72 1/3,8 25,5 Bega- 9* 1/5,7 17,4 25 1/2,9 34,2 13 1/1,4 56,5 47** 1/3,1 32,4 Veche Bega 30 1/ 17,0 16 1/4,6 21,9 18 1/1,3 78,2 64 1/4,3 23,5 Timiş 176 25 1/7,0 14,2 73 34 1/2,1 46,6 23 16 1/1,4 69,5 272 75 1/3,6 27,6 Timiş- Bega 42 1/4,2 23,9 35 1/2,1 48,0 18 1/1,3 78,2 95 1/2,9 34,9 ensemble Bârzava 15 1/11,7 8,5 19 1/3,8 26,0 19 1/1,2 82,5 53 1/5,1 19,5 Other 30 1/5,9 17,0 14 1/5,2 19,2 22 1/1 95,5 66 1/4,1 24,3 courses Total of registered 161 129 144 434 phenomena * For Bega-Veche the statistics can be made only after 1830 when the adjustment works began. * * From the same reason 46 floods in 142 years are taken into account. Source: A. Zănescu, 1974 In Banat, from the mentioned statistics comes out the fact that in the interval between 1700-1972, there were 135 years with high waters and a number of 434 floods on all the rivers, floods with a frequency of 49,4%4 (table nr. 2), from which we can deducethat the frequency of the high waters happens at a quick pace on the rivers from 2 Idem, p. 31 3 Al. Zănescu, Statistica apelor mari, istorice, pe râurile din Banat. Hidrotehnica, 19, Bucureşti, 1974, p. 231 4 Idem, p. 232 92 A history of about 300 years of high watersand hydrotechnic constructions in Banat(I) Banat, almost annually, covering all months of the year and the greatest balance comes to February, March, April and May (fig. 2). High waters distribution by seasons shows differentiations from one season to another. Thus, in spring there are the most floods (48%), then in winter (25%), in autumn we have the lowest frequencies (5%), although in Banat the second pluviometric maximum is recorded in the autumn months as a consequence of the influences of the submediterranean climate (table nr.

Load more