Technikatörténeti szemle 5. (1970)

KÖZLEMÉNYEK - Károlyi Zsigmond: Vásárhelyi Pál, a Tisza szabályozás tervezője és az Al-Duna szabályozás úttörője

In the 1830-s Vásárhelyi started — in the interest of steam navigation and under the guidance of Széchenyi — the regulation of the Iron Gate and the other rapids on the Lower Danube, and constructed the Lower Danube Road excavated mostly in the steep rock face. (This road was later named after Széchenyi.) The Iron Gate Barrage under construction will offer a permanent solution to safe navigation over this section and it may be of interest, in this connection, to remember the descriptions and reviews in the contemporary engineering literature and to immortalize thus the memory of the pioneers of this regulation, István Széchenyi and Pál Vásárhelyi. The number of papers published by Vásárhelyi is modest, but of a considerable scientific value. His interest was first devoted to triangulation, mapping and river regulation problems encountered in practice. The first general ground levelling of Hungary was subsequently completed under his guidance in 1843. The hydrometric measurements conducted in the 1830-s were the first in the world, no earlier example being known for steamflow determination by current-meter measurements at discrete points as was done by Vásárhelyi in the Budapest cross-section of the Danube. The paper compiled on the basis of detailed measurements, verifying the parabolic distribution of velocities in the vertical direction („A sebesség fokozatáról folyó vizeknél, felvilágosítva egy a Dunán mért keresztmetszés. . .által. . .különböző vízállásoknál" — "Ranges of velocity in flowing water, observed in a cross-section of the Danube ... at different stages ") has been published in Hungarian only, in the Annals of the Hungarian Academy of Sciences, Vol. 1845. and remained thus unknown outside of Hungary. Yet, as pointed out by S. Kolupaila in his work "Bibliography of Hydrometry" (Indiana, (U.S.A.) Univ. of Notre Dame, 1961. p. 15.) one of the first representations of the rating curve has been published in this paper. The interesting paper by Vásárhelyi on the hydrological conditions of the Danube in the Budapest cross-section remained abroad also inaccessible to engineers. In recognition of his work he was elected in 1835 as a corresponding member and in 1838 as an ordinary member of the Hungarian Academy of Sciences. His most significant work was the preparation of the plans for the regulation of the Tisza River, wich form the main subject of the present publication. While Széchenyi had been working on the preparation and organization of the regulation works, these plans were considerably refined and improved by Vásárhelyi in 1845 and 1846. In this study the little known final form of the plans is discussed in detail, emphasising besides its practical theoretical significance in the history of Hungarian hydraulic engineering. In harmony with the economic-political ideas of Széchenyi, the need for the comprehensive control of the entire Tisza Basin, for the co-ordinated solution of river regulation, flood control, reclamation and irrigation along the Tisza River and its tributaries had been emphasized. He was the first to recognize and emphasize the close interrelation of flood control (levee construction) and river bed regulation, which cannot be treated separately, as was done in earlier practice

. The economic significance of the project has been and stiil is, to this very day, too great to be evaluated, since 1,2 million hectares of flood plain area in the Tisza Valley were protected against annually recurring inundations and by extending the area available for agricultural production, further by enabling the evolution of traffic on land and water, the bases were laid for the later economic and population development of the Great Hungarian Plain.