Dr. Kubassek János szerk.: A Kárpát-medence természeti értékei (Érd, 2004)
Dr. Dénes Lóczy: Mosaics from the history of fluvial geomorphological research in Hungary
^/fáoáaócá from l/te Aíitoy-u ^imna/geo^fuy^fiÁ<>éoQÍccí/ iteáea^^ vn. éffuMgamt o • • —"... valleys are cut by the same waters which run in channels in them." (p. 377) Being a geologist, however, he is liable to attribute greater importance to 'all other agents', external environmental influences on the channel: "The work, however, which is performed by the river, depends on all other agents rather than the theoretical principles of ivater movement. " (p. 375) At the same time, LÓCZY was aware of the international achievements in the hydrological research of rivers and claims that "... the condition to bends lies in the activity of the river itself." (p. 390) He refers to GREBENAU, who observed that the water surface rises asymmetrically in the bends, and correctly links this phenomenon to meandering. This was a revolutionary thought since the recent theories of meander development, based on local scour and fill resulting in riffles and pools, also rely on water-surface measurements in the Alps and the Rocky Mountains among other areas (LÓCZY, D. 2000). 2. The assumed LÓCZY's Law' L. LÓCZY Sen. emphasizes in many of his papers that the contribution of sediment load is indispensable for really efficient erosion. Another observation related to sediment transport was called 'LÓCZY's Law' by his student, Jenő CHOLNOKY (1923)- According to LÓCZY, rivers 'prefer' to incise into hard rocks since along such sections the amount of sediment entrainment equals that of transport. In 'soft' (ie. easily erodible) rock surfaces the quantity of entrained sediment increases, the channel degrades', ie. braids and shifts or, where it transports its own load, begins to meander. This regularity came very handy for those who wanted to explain the origin of superimposed valleys. Superimposition used to be more frequently employed in explanations of valley formation than today. CHOLNOKY, however, had an engineering background and, when he tried to apply his master's law, arrived at contradictory experiences and instinctively felt that LÓCZY's view is untenable. Since then numerous research findings abroad point to the frequent independence of river competence from capacity. Since to date no one has been able to find the formulation of 'LÓCZY's Law' in his life-work, printed or hand-written, it comes as no surprise that there are at least two different interpretations. Therefore, the 'law' cannot really be refuted. From the aspect that if river flow is 'hindered' by its own sediment load, it shifts over harder rock O 12.9 O
