The effect of lateral bank erosion on the mangrove channel of Langkawi Island, Malaysia

Abstract. Hashim SS, Abd Aziz KN, Tajam J, Mohd FA, Roslani MA, Kamaruddin SA, Latif ZA, Maulud KNA, Ahmad A, Azahary WAHWM. 2025. The effect of lateral bank erosion on the mangrove channel of Langkawi Island, Malaysia. Asian J For 9: 97-107. Mangrove forests, essential marine ecosystems that support marine life and economic activities, face threats from natural factors like monsoon seasons and artificial threats of human interventions. The extent of mangroves in channels depends on the hydrological properties of lateral erosion, necessitating a thorough assessment for conservation. This study utilizes erosion pins to observe lateral bank erosion in two different scenes of mangrove channels within Langkawi Island; the pristine (Selat Tuba) and the eventful channel (Sg. Kilim). Findings reveal varying erosion rates (0.03-0.62 m/year) in Sg. Kilim due to monsoon seasons and human activity influences, while Selat Tuba remains stable throughout the monsoon seasons with a ratio of 2.7:1. The study categorizes eroded banks into four distinct types based on erosion patterns across the upper, middle, and lower sections. The spatial differences in erosion types that influence the bank's conditions emphasize the need for tailored conservation approaches. Statistical analyses highlight significant variations in lateral erosion rates in Sg. Kilim underscores the impact of uncontrolled tourism activities. Sustainable management efforts should be prioritized to mitigate lateral erosion, especially in Selat Tuba, where human activities may exacerbate the issue in the future. This research provides valuable insights for coastal resource management, emphasizing the crucial role of maintaining mangrove channel bank stability.