Temporal Analysis of Coastal Erosion in Mangalore Coast Using Multisource Satellite Images

The shoreline is a more dynamic, and complex region of all geological features present, as it has a mixed results of tidal, Aeolian, tectonic, and sometimes river in activity. A shoreline can be defined as the region where the water bodies such as lakes, seas, and oceans meet the land. It has immense geological, geomorphological and ecological interest. The coast of Karnataka state extends from Talapadi in south to Sadashivgad in north covering a distance of about 280 km. In this study, an attempt has been made to investigate the shoreline transformation along the coast of Mangalore, of a stretch of 25.3 km. Fair weather satellite images of LANDSAT from 1972 to 2021 were used to delineate the shoreline. A Linear Regression Rate-of-change (LRR) and an End Point Rate (EPR) statistics were carried out using Digital Shoreline Analysis System (DSAS) computer software of United States Geological Survey (USGS) as an extension tool of ArcMAP v10.2 software. Highest EPR of about 3.62 m/year was noticed in the Tannirbavi beach, whereas highest LRR was about 3.54 m/year in same place, both indicating accretion. Highest erosion was noticed in Ullal beach with an LRR of 5.23 m/year and EPR of 5.62 m/year at Someshwara beach respectively. An overall average accretion was found to be 1.265 m/year throughout the Mangalore coast and overall average erosion as 1.136 m/year.