Spatiotemporal change detection of coastline with satellite remote sensing
The Vasai creek, the Manori creek and the Thane creek are estuarine creeks in the Arabian Sea near Mumbai.This area has the highest economic development rates in India. In this estuarine area, extensive land use change including embankments was observed and various constructions have taken place due to rapid urbanization and industrialization. Improper and unplanned sustainable coastal zone management may lead to severe environmental problems such as sea water intrusion, coastal erosion, siltation of river channels and land subsidence, etc. This study evaluates the utility of satellite remote sensing imageries by deploying multi-temporal Landsat series satellite data (MSS, TM5 and OLI) and high-resolution Google earth imagery including a topographic map of Mumbai also. From the change analysis performed through this study, huge variations in the position of the coastline were observed. The Thane creek shows very drastic change near Sewri while Vasai creek near Rai village. The Manori creek shows an overall shrink in its area. At some places on the coastline, large sediment depositions were observed. The JLN port trust area shows vast change due to the encroachment of sea water. In 1954, the area where current JLN port trust is established has only 0.65 km2 area, but after land reclamation and development in sea water for JLN port trust, the area converted to 3.94 km2 in the year 2015, depicting a vast change of area as 0.5 km2 per year. One of the most noticeable impacts of coastline changes in the study area is the narrowing down of all estuarine creeks at many places and extension of JLN port trust into sea water. Coastline and coastal area change detection are important for environment planners and coastal area planners to protect coasts from climate change.