Further comment on drag and reconfiguration of macrophytes

Abstract

1. The paper by b7Sand-Jensen (2003, Freshwater Biology, 48, 271), and the subsequent comment and reply (b9Sukhodolov, 2005, Freshwater Biology, 50, 194; b8Sand-Jensen, 2005, Freshwater Biology, 50, 196), are discussed. I present partial theory describing how the macrophyte bending angle changes with increased flow velocity, demonstrating a nonlinear relation. 2. While b8Sand-Jensen (2005) is correct that plant wetted area is the only characteristic area that can be measured easily, some other measure of the exposure area of the plant stand to the flow may be preferable. The relationship in b7Sand-Jensen (2003) between the dimensionless drag coefficient and flow velocity depends on the definition of characteristic area. Hence, the analysis involving the drag parameter in b7Sand-Jensen (2003) should be interpreted with care. © 2005 The Author.