STUDI EROSI TEBING PANTAI DI KOTA MANNA, KABUPATEN BENGKULU SELATAN

• Main Author: Chairunisa Utari, Larissa
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/45348
• Institution: Institut Teknologi Bandung

This study explains the erosion process on Manna City coastal cliff toe caused by waves and tidal activities, and also simulates the erosion on Manna City coastal cliff toe on 2007- 2016. Manna City coastal cliff is consisted of sedimentary rocks and is one of the most actively eroded cliff in Indonesia. Mathematical models are used to calculate the erosion, using breaking wave height, wave period, tidal elevation, and cliff material strength as input data. Wave period and height are calculated using Svredruv Munk Bretschneider (SMB). Then, wave height is converted into breaking wave height with an assumption that the wave period is constant. Simulation is done on four scenarios using an empiric cliff erosion equation caused by plunging and spilling breaker type. Cliff erosion model is shown as a 2 dimensional mode in a vertical (z) and beach perpendicular (y) direction. This model uses an elevation grid (dz) in a vertical direction of 0.1 m mean sea level (MSL) value of 0 m as an elevation reference, time step (dt) of 6 hours, and clff material strength (R) of 1,5x106 m9/4 det3/2. This model assumes that there are no cliff failures and all eroded sediment goes back into the sea. The result of this model shows an erosion distance of 10.31 m for spilling breaker and 51.78 m for plunging breaker from 2007-2016.