Table 2 Palaeohydraulic formulae used in calculations in the present study (Bagnold 1966; Friend and Moody-Stuart 1972; Klimek 1972; Miller et al. 1977; Koster 1978; Saunderson and Jopling 1980; Carling 1983; Costa 1983; Williams 1983; Komar 1996; Bridge 2003; Zieliński 2014)