Is sinuosity a function of slope and bankfull discharge? – A case study of the meandering rivers in the Pannonian Basin
J. Petrovszki1,2, G. Timár2, and G. Molnár2,31Water Management Research Group of the Hungarian Academy of Sciences, Budapest, Hungary 2Department of Geophysics and Space Science, Eötvös Loránd University, Budapest, Hungary 3Geological, Geophysical and Space Science Research Group of the Hungarian Academy of Sciences, Eötvös University, Budapest, Hungary
Received: 15 Sep 2014 – Accepted for review: 12 Oct 2014 – Discussion started: 04 Nov 2014
Abstract. Pre-regulation channel sinuosities of the meandering rivers of the Pannonian Basin are analysed in order to define a mathematical model to estimate the influence of the bankfull discharge and the channel slope on them. As a primary database, data triplets of slope, discharge and sinuosity values were extracted from historical and modern datasets and pre-regulation historical topographic maps. Channel slope values were systematically modified to estimate figures valid before the river regulation works. The bankfull discharges were estimated from the average discharges using a robust yet complex method. The "classical" graphs of Leopold and Wolman (1957), Ackers and Charlton (1970b) and Schumm and Khan (1972) were compiled to a set up a theoretical surface, whose parameters are estimated by the real values of the above database, containing characteristics of the Pannonian Basin rivers.
As a result it occurred that there is a two-dimensional function of the bankfull discharges, which provides a good estimation of the most probable sinuosity values of the rivers with the given slope and discharge characteristics. The average RMS error of this estimation is around 15% on this dataset and believed to be the effect of the non-analysed changes in the sediment discharge and size distribution.
Petrovszki, J., Timár, G., and Molnár, G.: Is sinuosity a function of slope and bankfull discharge? – A case study of the meandering rivers in the Pannonian Basin, Hydrol. Earth Syst. Sci. Discuss., 11, 12271-12290, doi:10.5194/hessd-11-12271-2014, 2014.