Coastal morphodynamic analysis in Buleleng Regency, Bali—Indonesia

• Published in: Natural hazards (Dordrecht) Vol. 111; no. 1; pp. 995 - 1017
• Main Authors: Marfai, Muh Aris, Winastuti, Ratih, Wicaksono, Arief, Mutaqin, Bachtiar W.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-03-2022; Springer Nature B.V
• Subjects: Accretion; Beach morphology; Beaches; Civil Engineering; Coastal management; Coastal morphology; Coastal processes; Coastal zone management; Deposition; Digital imaging; Earth and Environmental Science; Earth Sciences; Environmental Management; Estuaries; Estuarine dynamics; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Grain size; Grain size distribution; Gravel; Human influences; Hydrogeology; Imagery; Kurtosis; Laboratory tests; Landsat; Mitigation; Natural Hazards; Original Paper; Particle size; Physical characteristics; Physical properties; Remote sensing; Satellite imagery; Sediment; Sediment transport; Shorelines; Size distribution; Skewness; Solid suspensions; Statistical analysis; Statistical methods; Surveys; Suspended particulate matter; Total suspended solids; Indonesia; Grain size; Shoreline change; Sediment cells; Buleleng; Morphology; Indonesia
• ISSN: 0921-030X; 1573-0840
• DOI: 10.1007/s11069-021-05088-8

Sediment as erosion product can affect shorelines, making sediment transport a key process to consider in coastal and shoreline management. Field surveys and secondary data can identify where suspended matters are distributed and deposited to analyze sediment uniformity factors: beach morphology and materials. This research set out to determine the Buleleng Regency's morphodynamic aspects based on the coastal landscape's physical characteristics and the processes acting upon each sediment cell. Field observations were conducted at five stations, from Tukad Gerokgak to Tukad Saba estuary. Jaelani's spectral transformation has been applied to analyze Total Suspended Solids using Sentinel 2A imagery. The laboratory test results of grain-size samples were processed on GRADISTAT, then the depositional environment and sediment transport direction were determined from average grain size, standard deviation, skewness, and kurtosis. Shoreline change, an indicator of coastal morphodynamics, was mapped from Landsat images in 2000, 2008, and 2019 using the Digital Shoreline Analysis System. Statistical analysis on GRADISTAT provided details on depositional environment and sediment transport and deposition based on grain-size distribution. Results indicate poorly sorted medium grain size: gravel (stone) to coarse sand, making up the sediment population from Tukad Gerokgak to Tukad Saba. Generally, sediment is deposited toward coarse, even very coarse, grain on a strongly sloping beach, and there is a high likeliness of sediment accretion. Identified morphodynamic characteristics suggest that the coastal landscape needs structural mitigation to overcome the accelerating impact of human activities and physical processes.