A review of large wood dynamics relevant to hazard characteristics for built structures

Abstract

Large wood exerts an influence on the topography and geomorphology of channels in areas of good vegetation development, and it is also an important component of riverine ecosystems. However, large wood may impact and damage buildings. The formation and failure of logjams can cause backwater rise, local scour, and the amplification of flow discharge, leading to more serious disasters. Therefore, quantifying the processes of large wood recruitment, entrainment, transport, deposition, accumulation and logjams failure is highly significant for the prevention of large wood hazards in channels. Based on existing research on large wood, this review provides a comprehensive analysis of large wood dynamics and hazards. First, the processes involved in large wood recruitment, entrainment, transport, and deposition are reviewed. Second, the results of large wood accumulation probability and the backwater rise, local scour, critical conditions of logjams failure and magnitude amplification of the flow discharge caused by large wood are analyzed comprehensively. Finally, large wood-related hazard mitigation measures are also introduced. Future research directions to improve the mitigation of hazards from large wood should concentrate on exploring quantification models for understanding how large wood impacts and accumulates on various built structures.