Author(s): Silmi Fatharani Rahmah; Firlana Hanifah; Luthfiyyah Dzakiyyah Wopa; Anthony Harlly Sasono Putro

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Keywords: Beach erosion; Equilibrium shoreline; Integrated shoreline management; Shoreline dynamics

Abstract: Shoreline changes is the result of dynamic processes that can occur due to continuous erosion and accretion along the coast. In Cemagi Beach, Bali, this occurrence could threaten the region’s economic standing as it relies primarily on the tourism sector. This study investigates shoreline change patterns at Cemagi Beach over a period of five years (2013–2023) using satellite imagery and GIS-based approaches. Shoreline dynamics were analysed with the Digital Shoreline Analysis System (DSAS) to calculate rates of change, and the Parabolic Bay Shape Equation (PBSE) was used to assess equilibrium shoreline using a Model of Estimating Equilibrium Parabolic-Type Shoreline (MeEPASoL). Results revealed significant variations, with maximum accretion of 87.60 m and erosion reaching –119.54 m over ten years. Annual averages showed 1.36 m of accretion and - 1.14 m of erosion. Beach erosion dominated the southern parts, while accretion was prominent in the northern regions. Ultimately, it can be observed that there is an imbalance between the erosion and deposition of sediment, resulting in a continuous fluctuating shoreline in Cemagi Beach. It is substantial to find the equilibrium state to evaluate the shoreline retreat and to obtain results which can be used to devise future beach conservative measures and to develop further integrated shoreline management plans.

DOI: https://doi.org/10.64697/978-90-835589-7-4_41WC-P2047-cd

Year: 2025