Estuary zone based on sea level salinity in Ciletuh Bay, West Java

The Estuary area is an area where there is a mixture of seawater with fresh water from the mainland. This estuary area is unique because seawater mixing with fresh water causes brackish water formation with fluctuating salinity. The fluctuation in salinity is influenced by the depth and shape of the water bed and the season. This study analyzes the estuary area (zone) in Ciletuh Bay, West Java, based on the rainy and dry seasons associated with bathymetry. The salinity value is obtained from Sentinel-2A image processing, using the salinity estimator algorithm’s calculation, namely the Cilamaya Algorithm. The results showed that the mapping of the distribution of salinity forms the estuary boundaries, and the variables of rainfall and bathymetry affect the distribution of salinity values. The shallower the water, the lower the salinity level. Conversely, the deeper the waters, the higher the salinity level. The statement is due to the influence of freshwater entry into the sea, which is also related to rainfall (season), affecting fluctuations between saltwater and freshwater.