DescriptionRiver training structures such as groynes, guide banks, longitudinal training walls, bottom vanes and surface screens all act on the primary flow field. Bottom vanes and surface screens, however, act on the secondary flow field too by inducing a helical water motion. This “transverse circulation” displaces sediment in another direction than the main flow direction. India already used surface screens in the 19th century, originally calling the screens “jhámps” and today referring to them as “bandals”. This usage relied mainly on practical experience, without systematic research. It was M.V. Potapov who, in the first half of the 20th century, carried out systematic experimental research and realized field applications in large rivers of the former Soviet Union. As he published in Russian only, his work became only known in other countries thanks to translations by R.I. Batalin. It still merits wider acknowledgement but now risks falling into oblivion. The present contribution therefore recalls Potapov’s work and presents recent field tests and research in Bangladesh and in the Netherlands. In Bangladesh, floating surface screens and high-water bandals were tested in the Brahmaputra-Jamuna River at Katlamari. In the Netherlands, the effects of a surface screen on water motion and riverbed morphology were tested in the laboratory and in a secondary channel of the river IJssel. The ensemble of experiences allows drawing conclusions on the practical suitability of fixed and floating surface screens.
|6 Aug 2021
|4th International Conference on the Status and Future of the World's large rivers
|Degree of Recognition