Coastline Modeling Using Stacked Curve Spline Tension Interpolation

Abstract

The coastal area is a dynamic environment influenced by atmosphere, land, and ocean interactions. Similarly, the position of coastlines is also changing due to natural and human-induced components, for instance, erosion, wave, daily tide, storm, and coastal development. In literature, coastline position can be identified based on proxies such as coastal features identified from an aerial photo or very high-resolution image and tidal datum-based indicators extracting from a ground survey. This research proposed a method in deriving datum-based coastline by integrating various bathymetric data, including single beam and multibeam echo sounding data, the National Digital Elevation Model, the national bathymetry data, as well as satellite-derived bathymetry data. The stacked curve spline tension method was applied to assimilate those various bathymetric data, and finally, the coastline was generated. Based on the accuracy assessment conducted, coastline similarity accuracy varies; namely, the LAT coastline had an accuracy of 29.28%, the MSL coastline was 65.45%, and the HAT coastline was 47.48%. These variations are due to several reasons, including the lack of input data, the density of depth data that varies greatly, the difference in data acquisition time between the data used for the LPI map and the data used in this study. Although the accuracy values obtained were not sufficiently high, the proposed method was quite promising to adopt. The method can be used as an alternative for the coastline model and overcome data, time, and cost limitations in providing national coastlines