Dr. Kubassek János szerk.: A Kárpát-medence természeti értékei (Érd, 2004)

Dr. Dénes Lóczy: Mosaics from the history of fluvial geomorphological research in Hungary

<s surfaces. But if 'LÓCZY's Law' is conceived to refer to channel inheritance, ie. the channel is more stable over harder rocks than over unconsolidated alluvia, it is naturally correct. CHOLNOKY (1925, 1926) related it to his theory of types of river reaches, which is based on LÓCZY's criticism. In his interpretation LÓCZY claimed that rivers braid where banks are erodible and where rivers can transport their own sediment load more easily, meandering ensues. CHOLNOKY'S theory is well known in Hungary: it claims that channel formation varies from place to place and depends on the balance of the river's ability to carry out work and the work needed to transport sediment. The ability for work is highest along rivers of 'torrential' flow since their water discharge can fluctuate rapidly and on a wide range. Thus, the dubious law has been of fertilizing influence on the development of our science. 3. Sediment transport and river mechanism CHOLNOKY'S classification of types of river reaches however, could not supply a final solution for all problems concerning fluvial processes and landforms and even served to trigger the until now most heated professional debate in the discipline, which took place on March 27, 1959. László KADÁR (i960) carried out flume experiments to clarify the mechanisms of rivers along upper and lower reaches. He arrived at the conclusion that 'stream autodynamics" (ie. internal hydraulic driving forces) are sufficient to create the same landforms which were associated with crustal movements and/or climate changes by Béla BULLA (1941, 1954a). All the partial issues raised during the discussion cannot be summarized in a nutshell here. It was a great achievement, however, that both geomorphologists and the representatives of related sciences present acknowledged KÁDÁR's endeavours towards incorporating hydrological thinking into fluvial geomorphological research. With this attitude he managed to relate eg. stream bed microfeatures with some thresholds of current velocity or, more precisely, with the transition state from laminar into turbulent flow. With this he was about a decade ahead of his time.