Fejér László - Lászlóffy Woldemár: A hidrometria magyarországi fejlődése (1700-1945) (Vízügyi Történeti Füzetek 13. Budapest, 1986)

Idegen nyelvű összefoglalók

DEVELOPMENT OF HYDROMETRY IN HUNGARY (1700-1945) László FEJÉR - Woldemár LÁSZLÓFFY The subject of this study is to present the development of discharge measurements in Hungary, in accordance with the classical interpretation of hydrometry. To ensure a proper survey, the introductory chapter is, after publications of S. KOLUPAILA and A. FRAZIER, a summary covering the general development of the science of hydrometry and its instruments, from the beginnings to the early nineteenth century. * According to our present knowledge, L. S. MARSIGLI was the first in Hungary who executed discharge measurements (around 1700 A. D., on the Danube) purely for scientific purposes. The results of his observations however failed to have a major impact on the domestic development of hydrometry. Owing to peaceful cirumstances, during the second half of the eighteenth century there was a faster development in the country's economic life and triggered by the needs of agriculture, the drainage of the land which has become water-logged during the Turkish occupation and the regulation of large rivers (Danube, Tisza, Körös rivers, ... etc.) had become urgent tasks. Accordingly, at the end of the eighteenth century preparatory work had been started for fluvial levelling and hydraulic measurements needed for the elaboration of regulation plans. In order to raise the public training of engineers to an academic level, the Engineering Institute (Institutum Geometricum, 1782) was established at the University of Pest. In their text-books the professors of this institute - HADALY, HOVÁTH and RAUSCH - were dealing mostly with theoretical knowledge while practical hydrometry was neglected. At that time in Hungary, flow velocity — and discharges necessary for the implementation of local regulation works and for the construction of mill-brooks were determined mostly by floats or by calculations (Chézy formula). The first great personality of Hungarian hydrometry was Mátyás HUSZÁR, under whose direction the mapping of the River Danube was started in the early 1820s. In 1825 HUSZÁR performed point measurments on flow velocity at Pozsony (today Bratislava) and at five near-by Danubian cross-sections by means of a Woltman-type current meter and in doing so he realized that to identical water stages both higher and lower flow velocities could be attached. This referred to the fact that discharges were changing in accordance with the actual slope of the water surface. On the basis of his measurements on the Körös rivers and on the Danube, Mátyás HUSZÁR made several recommendations concerning the improvements of the methods and instruments of the measurements. Serial point measurements for flow velocity, reaching down to the bed, were performed at the end of the Danube-mapping (after 1835), mostly during low-water periods in 1836 and 1838. The means of these measurements and their execution were reported by another leader of this mapping, by Ferenc HIERONYMI.