ABSTRACT

Debris flow is a phenomenon that occurs in both upstream and downstream watersheds. Heavy rains cause debris flow, which transports some of the material in the watershed, including pieces of wood from broken trees in the upper reaches of the watershed. The aim of this study was to conduct additional research on the phenomenon of accumulation of wood debris flow upstream of the bridge using flume experiments as the method. The wooden bridge model and a wood piece model were used as a bridge and wood debris models in this study. A tool was created in this study to release wood upstream, and the amount of drifted and trapped wood was counted. Furthermore, the depth of flow will be measured as wood debris accumulates upstream of the bridge model. According to the findings of this study, the backwater rise increased with the amount of wood debris flow accumulation on the upstream side of the bridge. According to the findings of this study, the accumulation of wood debris flow had an effect on the backwater rise upstream of the bridge. The lowest value for backwater rise is 0.02, while the highest value is 0.21. Furthermore, the accumulation of wood debris flow increases in accordance with the increase in flow discharge on the bridge caused by wood debris accumulation. For each diameter of 4 mm, 5 mm, and 6 mm, the average backwater rise difference between maximum and minimum discharge is: 0.058; 0.064; 0.1. This is due to the fact that as the discharge in the flow increases, the area upstream of the bridge model facing the direction of flow increases. This research is one step toward improving flood management knowledge.