Extracting Shoreline from Satellite Imagery for GIS Analysis

A shoreline is a highly dynamic part of the earth’s surface. Advanced remote sensing (RS) and geographic information system (GIS) techniques are being used for detection of shoreline position and change analysis. In this paper, a new methodology for automatic shoreline extraction is demonstrated and analyzed using Landsat 8 Operational Land Imager (OLI)/Thermal Infrared Sensor (TIRS) images. The methodology involves several stages consisting of preprocessing of satellite images, band selection, coastal water index (CWI) preparation, normalization of binary images, Otsu thresholding technique (named after Nobuyuki Otsu) for the land and water separation, image noise correction with morphological filter (image morphology), seawater separation from waterbody, vectorization of classified binary image, polyline conversion from polygon vector, shoreline selection, and generalization of the final shoreline. The positional accuracy of the final shoreline is evaluated with expert captured shoreline. It was observed that the average positional difference between computer generated shoreline and expert digitized shoreline was less than a pixel resolution. The proposed methodology is very helpful in any coastal application where the shoreline is used as a parameter. It also reduces the time of human intervention. © 2020, Springer Nature Switzerland AG.