Ideas About the Development of Hydrometry.

The development of hydrometry - the base of any operative hydrological activity - is closely interrelated to the technical and economical development of the society. The beginnings of our hydrometrical measurements are dated back to Pal Vasarhelyi, to the problems of a one-time river regulation project. Later, hydraulic power generation and irrigation stimulated the development of hydrographical measurements. After WW II, our hydrometry was characterized by an increase in the quantitative demands, by the compilation of theoretical and practical textbooks (E. Nemeth, O. Starosolszky, L. Muszkalay), by a wide use of hydrometers and telemetering systems, and by the expansion of mechanized data-processing and up-to-date electronic systems. An important feature of this development trend was the measurement of the components of flow velocity. In streamflows the motion of water is three-dimensional which must be taken into account if its discharge must be determined and knowledge about pulsation is also indispensable in the solution of several hydraulic problems among others in the determination of the quantity of transported material.