Author(s): Ghufran Ahmed Pasha; Norio Tanaka
Linked Author(s): Norio Tanaka
Keywords: Driftwood; Forest density; Aspect ratio
Abstract: During tsunami events, destruction of coastal forests may produce significant amount of driftwood or large woody debris (LWD). This driftwood can cause secondary damage to buildings by collision. To limit such devastation, experimental study was conducted in flume to figure out the optimum inland forest design which would trap the maximum driftwood at the foot of trees because the trapping height greatly affects the damage to the forest itself. Driftwood trapping height in terms of single row continuous forest and double rows forest with alternate gaps was investigated against different‘forest densities’and‘forest length-width ratio (aspect ratio) ’. In case of single row continuous forest, increasing forest density resulted in all lengths of driftwood to attach near the ground. However with driftwood length larger than the forest length, even with sparse forest, favorable trapping results were seen with a series of smaller aspect ratio forests with alternate gaps (double rows forest).