Bankfull frequency in rivers

Bankfull discharge represents the maximum flow that a river can convey without overflowing its banks [5,19,42,77]. This discharge is considered morphologically significant as it represents the separation between river formation processes and floodplain processes [19,42,57]. Bankfull discharge is considered deterministic and as such is frequently used to estimate the channel-forming or dominant discharge of alluvial rivers [19,27,66]. Channel-forming discharge is a theoretical discharge that if maintained for an indefinite period of time (i.e., held constant) would produce the same river morphology as that of the long-term hydrograph [2,19,66,69]. Bates and Jackson [9] define channel-forming discharge as the “discharge of a natural channel which determines the characteristics and principal dimensions of the channel.” The concept of channel-forming discharge is applicable to stable rivers [19].