Flow, sediment transport and bed deformation around spur dikes on erodible and on inerodible bed fields

Spur dikes have been constructed to redirect the stream flow, protect streambanks from erosion, and improve stream depth for navigation since long time ago. In addition, in recent years, spur dikes are expected to be used as one of the restoration methods on aquatic habitats as they produce local scours and sediment deposition areas around them. There have been significant number of papers about spur dikes and abutments, however, almost all the above-mentioned studies did not target the characteristics of sediment transport and bed deformation around spur dikes set on a inerodible bed field in great details. In this paper, the authors summarized the characteristics of flow, sediment transport, and bed deformation around both spur dikes and abatements set on erodible and inerodible bed fields in natural rivers, experimental flume, and numerical analysis. Subsequently, as a method to create sediment deposition areas along the both banks on inerodible bed field, acute angle of submerged spur dikes were introduced.