Impact of urbanization on creeks of Mumbai, India: a geospatial assessment approach

Abstract

Creeks are the inherent coastline feature that connects rivers to the sea and plays an important role in the ecological processes and the material transfer. In the present study, an impact of urbanisation on the creeks of Mumbai, India namely Thane, Malad and Manori creeks, has been addressed. Multi-temporal satellite images of Landsat for the years 1972, 1994 and 2016 are considered to perform the changes in the mudflat and growth of the mangrove, as well as the changes in creeks width apart from the Land use Land cover (LULC). Object-based image analysis using multi-spectral resolution confirmed that there is an overall increase in the spatial extent of mangroves and reduction in the width of all the creeks. Mangroves around Thane creek and Manori creek have increased from 50.7 km2 to 57.6 km2 and 8.4 km2 to 25.2 km2respectively. However, there is a decrease in mangroves around Malad Creek from13.3 km2 to 9.7 km2during 1972 to 2016. The relationship between the creek geometry and LULC was also explored, and it has been revealed that the creek width has reduced due to urbanisation. Life expectancy analysis projected a further reduction in the width of the creeks for the years 2025 and 2050. The study suggests that there must be stringent bye-laws for disposal of sewage into the creeks and development activity near the creek areas. Further, upper stretches of the creeks require cleaning and dredging so that the tidal water will be approached up to the upper portion to maintain the creek ecosystem.