Porosity Effects on Wave Transmission Through a Bamboo Fence

Abstract

Coastal shoreline in the Mekong Delta in Vietnam have been eroded significantly in the past decade due to climate change and sea level rise. Many measures have been used to protect the shoreline from erosion, which could be solid-structure measures and natural-based solutions. A solid structure is nowadays unsuitable for both economy and foundation reasons in silt coastal areas whereas the natural-based solution is becoming more concerned and priority. Mangrove planting is the most environmental-friendly and sustainable soft-structure measure for reducing waves along the coast. However, new mangrove plants are impossible to grow in such severely eroded coasts. Therefore, using a bamboo fence to reduce wave energy and to increase sedimentation for new mangrove growth is becoming a suitable solution along Mekong Delta coastlines. Non-hydrostatic model SWASH (Simulation Waves till Shore) is applied in this study to simulate waves transmitting through bamboo fences. Results show that the fence porosity has a significant effect on wave transmitting through a bamboo fence. There is about 11% to 72% reduction of wave height for the fence porosity of 50%. In addition, the fence with porosity of 90% results in a maximum of 29% wave height reduction. Finally, the transmission coefficient decreases with increasing the relative fence thickness.