Coastline changes monitoring induced by man-made structures using synthetic aperture radar: A new simple approach

Abstract

This study presents a new simple approach to detect the coastline changes due to the construction of man-made structures. The new approach uses low-pass filter to reduce the speckles errors and Otsu thresholding method the create binary image. Then, a closing morphological operation was conducted to improve the binary image. In the final step, the canny edge detection is used for coastline delineation. The coastlines changes analysis was done by using Digital Shoreline Analysis System (DSAS). In general, the processing steps of this new approach is semi-automatic processes, it does not require manual digitization to extract the coastline. This method was tested using two independent synthetic aperture radar (SAR) satellite images, i.e., ALOS-1 and Sentinel-1 SAR data. The results show that this new approach produced better results than other well-known methods. This new approach detects clearly the man-made structure and its impact to the coastal zone, i.e., abrasion and accretion. The study area is located in Pengambengan Port, Jembrana Regency, Bali, Indonesia. In addition, the result of this study can be used as evaluation parameters for future development of Pengambengan port or re-design of present structures.