Kertai Ede: Magyarország nagyobb vízépítési műtárgyai. Tavi kikötők (OVH, Budapest, 1974)
Tartalomjegyzék
I. HARBOURS ON LAKK BALATON Lake Balaton, also known as the sea of Hungary, is the largest warm-water lake in Central Europe. At a width of 6 to 14 km and a length of 77 km, it covers an area of round 600 sq.km. The 195 km long shoreline has been developed for recreation with numerous summer homes, hotels and bathing beaches. The lake is eminently suited for summer holidaymaking, recreation and for all kinds of water sports. Increasing numbers of tourists are attracted from year to year and the number of visitors has exceeded 2 million in a year. The first historical data on Lake Balaton date back to the 3rd century A.D., under the Roman emperor Galerius the lake has been used intensively for recreation and probably also for navigation. The first steamboat appeared rather early, in 1846, and 11 harbours have also been built to make water traffic possible. The average depth of the large, soft-water lake is not more than 3.0 m, increasing to 11.5 m only over a length of a few hundred metres in the Tihany Narrows. This trough is scoured by currents shifting back and forth between the two basins and attaining velocities up to 0.8 m/sec. At such times the difference between the levels in the two basins is as great as 0.4 m. The volume of water stored in the lake is 2 thousand million cu.m, discharged from the 5775 sq.km large catchment. Owing to the shallow depth the water in Lake Balaton attains in summer a pleasant temperature of 21 Centigrades on the average within a brief period, but on warm summer days and in the shallow parts temperatures of 27 to 32 Centigrades have also been recorded. In a width of about 100 to 400 m the bed material along the southern shore consists of very fine sand, which forms mildly sloping beaches. At a distance of round 100 m from the shoreline the average depth ranges from 1.0 to 1.2 m. The slopes on the northern shore are steeper. In summer, Lake Balaton is eminently suited for bathing, recreation, sailing and angling, so that it has become a frequented center of water-born sports. In winter a short cold spell is enough to make the lake freeze over. Ice sailing craft have attained speed over 100 km/hour. The water is abounding in fish, with piers and bungalows built for anglers. Navigation serves up to 90% the interests of recreation, with harbours built accordingly. For the majority of harbours built on Lake Balaton in the past century timber was used as the main construction material. On the norther shore these consisted of 30 to 50 m long wooden piers, with 25 to 30 m long pier heads supported by pile bents. On the southern shore, owing to the flat slope, 100 to 300 m long rubble-mound breakwaters were necessary, with the timber pier built at the end thereof. These harbours were repeatedly destroyed by ice pressure. For this reason rubble-mound piers became popular on the northern shore as well in the second half of the past century, but the wooden pier head was still retained. On the southern shore, however, the harbours built were of the closed-basin type, with two solid breakwaters enclosing them. These types of harbour design prevailed even in the first years of the present century. Construction activities were interrupted during World War I and the following austere years, i.e., from 1914 to 1925. After 1926 all harbours were improved and four new ones were built. By the end of the thirties all timber harbour structures were replaced by rubble and concrete structures. The number of passengers carried has attained 2 million by 1966 already. Lake Balaton is linked to the international waterway, namely the Danube, by the 123 km long Sió Canal. The canalization thereof has been started by completing one of the barrages, earthmoving work and by raising the bridges. Until the remaining barrages are built navigation is possible only at times when water is released (35 cu.m sec) from the lake. The Sió Canal is not envisaged to become a continuously navigable waterway in the near future. 15
