Why Do We Need Bankfull and Dominant Discharges?

Abstract

AbstractWithin scientific hydrological, geomorphological and also engineering literature the two discharges that very often demand attention of hydrologists as well as ecologists and river engineers and water catchment managers are, respectively, the dominant and bankfull discharges. What are they? Do we really need them and why? The present paper explains the main ways of the dominant and bankfull discharges determinations and calculations. As far as the dominant discharge is concerned, the most important methods to find its value are: the Rzanicyn, the Debski, the Lambor, the Marlette and Walker, the Wolman and Miller, and the Makkavieiev methods. When considering bankfull discharge, the most important concepts and definitions as well as methods of its determination are: the Williams, the Wolman, the Schumm and Brown, the Riley, the Woodyer as well as the Radecki-Pawlik and Skalski methods. All those concepts and methods are described. Additionally, examples of bankfull calculations are given from one of the Carpathians rivers to show the difference obtained in bankfull values using different methods. Both morphometric and biological methods are used to determine bankfull. Special attention is given to biological approaches of bankfull methods since the Water Framework Directive gives priority to biological measures and findings along river and stream reaches.KeywordsDominant dischargeBankfullMountain streamRiverWater framework directive