Effects of hydraulic structures on river morphological processes

Abstract

Study of hydraulic structures such as groins and bandal-like structures can provide valuable information on their influences on morphological processes in natural rivers. These structures usually used for bank protection and formation of deep navigation channel can locally create complex flow patterns, reduce flow velocities and also increase the flood levels. Most of the previous studies are focused on structures like groins under non-submerged flow condition. However, the recent demand of nature friendly low cost and sustainable methods for river bank protection and channel formation leads to the necessity of study different type of structures like bandal-like structures. In this context, this study investigates the flow characteristics and sediment transport process influenced by bandal-like structures through laboratory experiments. The experiments were carried out under live-bed scour condition with sediment supplied from the inlet for two submergence (non-submerged and submerged) conditions. The experimental measurements contribute to better understand the mechanism of deposition/erosion process around different type of hydraulic structures. The performance of bandal-like structures considering the erosion around the structures, the deposition near the bank and the formation of deep main channel show promising results compared with conventional structures such as groins (impermeable and permeable ones).