Vízügyi Közlemények, Kivonatok, 1965

Dégen Imre: Az 1965. évi dunai árvíz és árvízvédelmünk fejlődése

(46) 3.6 FLOOD CONTROL OPERATIONS IN THE MOHÁCS REGION By E. Szilágyi, Engr. (For Hungarian text see pp. 245) Flood control responsibilites of the South-Transdanuvian District Water Authority extend to a short section of levee only, on the right-hand bank of the Danube, between river stations 1448 and 1428 km, i.e. the section between Mohács and the southern border. The length of the levee is 20.1 km and the area protected thereby is 29.500 hectares. Contingencies which arose during the flood within the town limits of Mohács and over the levee section downstream of Mohács, are outlined in Chapter 1. A brief review of the development history of the levee system is given and the main causes of difficulties during high water arcpointed out as the unreliability and structural inhomogeneity of the old levee body. Hazards arising from the saturation of the levee body can be eliminated, but no practical possibility exists at the present for improving adverse subsoil conditions, which result in piping and the formation of boils. A plan of the levee is shown in Fig. 3 while a typical cross section is given in Fig. 4. Saturation and underseepage presented the mam hazards along the entire length of the levee. Protective operations are described in Chapter 2. These were continued from the 31st March to the 14th April with minor interruptions, and then continuously to the 15th July. Peak stage occurred on the 19th June. Bed fullnes of the Danube and the three major tributaries over the lower reach, namely the Dráva, Tisza and Száva Rivers, and their mutual interference is illustrated in Fig. 7. An explanation is offerred thereby for the extreme stage and slope conditions over the lower Danube reach A review is subsequently given of methods of levee protection, and those actually applied are described more in detail, with illustrations attached in Figs. 8 to 16. The more important methods comprised ballasting of the landward slope, construction of counter-head sublevee basins and light sheet piling cutoffs. A detailed account is given on works on various levee sections, with illustrations in Figs. 17 to 21. The organization of protection and construction work is outlined and main data of protection expenditures are compiled in Table I. Studies and observations conducted during the high water for determining the effect of precipitation, ballasting of the landward slope (Figs. 22—23) and estimating underseepage discharges, are described in Chapter 3. In Chapter 4 the experiences gained are summarized briefly.