Vízügyi Közlemények, 1973 (55. évfolyam)
4. füzet - Rövidebb közlemények és beszámolók
tion of the Tisza Valley was a prerequisite of economic development Work was actually started around the middle of the 19th century, as a result of which Hungary reclaimed more land from the water than the entire reclaimed area in the Netherlands or than the area affected by flood control development in the Po Valley in Italy. The Tisza Valley plays an important role in the economic life of Hungary, by accommodating 40% of the 10 million inhabitants of the country and incorporating 12% of the national property. One-third of the arable lands of the country is in this area and more than one-half of the agricultural products is produced here. In 1970, round 80% of the total water demand in the Tisza Valley went to agricultural uses. In the wake of industrial development the industrial water demand is likely to increase at a high rate and is expected to attain 30 to 40% of the total demand by 1985. The complex development of water management in compliance with economic advancement in the Tisza Valley, and in the whole of Hungary, is an essential prerequisite of economic growth of the entire country. 2. Complex development of water management in the Tisza Valley Water development in the Tisza Valley was started by flood control and river regulation. The decisive impetus to large scale work was given by the great floods in the years 1844 and 1845. The development programme was elaborated thereafter by I. Széchenyi. The technical concept of improvement, the plans for regulating the Tisza River, were elaborated by the eminent water engineer of that time, P. Vásárhelyi, who envisaged the cutting of overdeveloped bends for shortening the course of the stream and the construction of flood levees. As a consequence of the progressive strengthening of the levees, ruptures kept decreasing in frequency, although flood stages increased (Fig. 1.1 — 4). Parallel to the construction of levees 112 bends were cut by 1890, shortening the course of the Tisza River in the plains by 37%- Lowwater regulation was started in 1900. At the present, 1,8 million hectares of land in the Tisza Valley are protected by main-line levees extending over a length of 2,800 km along the rivers. The utilization of about 20% of the area of Hungary is made possible by this system of protecting levees. In addition to the improvement of the levee system, the canalization of the Tisza River is continued as part of the comprehensive water management project, by constructing a sequence of barrages, for purposes of water utilization and damage aversion alike. Drainage of surface waters accumulating in the plains has been realized over more than 4 million hectares, of which 3.2 million hectares are in the catchment area of the Tisza River (Fig. 1.1 — 5). The aggregate length of drainage canals is 24,000 km with a total pumping capacity of 500 cu.m/sec. The specific drainage capacity is at present 26 lit sec.sq.km, capable of draining spring inundations of medium frequency in 21 days on the 17259
