Detection of Arosbaya Coastline Changes Using Sentinel-2A (Study Year of 2015-2018)

Abstract

Coastal changes are influenced by several natural conditions like beach balance and estuary. The most obvious fact from this condition which can be seen by 10 meter resolution of Sentinel-2A imagery is the erosion and accretion at the coastal area. This study found that the average of Arosbaya coastline changes from 2015 until 2018 suffer from erosion up to -1.099 meters. The coastline changes in Lajing village is uniform from south to the north. Almost all coastline shave eroded, with the average of -16.365 meter erosion and -83.105 meter maximum erosion value. However, Tengket village which is located in the north of Lajing shows different result. A high number of accretions is identified in this village with accretion rate up to 15 meters and the maximum accretion rate up to 275.0432 meters. The condition of Tengket village shows that the new land is unstable. It is not only because of natural ocean parameters from south still influenced by the Madura straits exit but also the sediment build-up from Tambangan estuary in the north of Tengket village. The effect of this condition takes form of area changes both of coastal villages from 2015 until 2018 period. There was 701.565 ha of area loss in Lajing Village; however, 902.6912 ha of new area was constructed in Tengket village making Arosbaya became 167.034 ha larger in 2018 than in 2015.