The nature of the fluid boundary layer and the selection of parameters for benthic ecology: reply to Lamouroux

Abstract

The near bed flow equations and definitions given originally by Carling (1992) are reviewed and are shown to be correct and unambiguous. The theoretical assumptions inate in deriving the governing equations are violated in non‐uniform, unsteady flow, such as occurs in shallow flow over rough beds, but in practice results obtained from log‐law models are often not significantly different from those derived from functions purporting to represent large‐scale roughness. This point was made carefully in the original paper.  More complex approaches now exist for modelling gradually varying, slightly non‐uniform flow which are modifications of uniform flow models. These are not readily applicable to field data commonly available to ecologists, however, and generally give little additional insight. Advances are only likely to be made when turbulent flow structure is better understood. Copyright © 1993, Wiley Blackwell. All rights reserved