3. Urban Expansion and Sea-Level Rise Related Flood Vulnerability for Mumbai (Bombay), India Using Remotely Sensed Data

Rapid growth and expansion of the developing world’s urban areas has both social and biophysical consequences such as increased population density, inadequate infrastructure and services, the expansion of impermeable surfaces, and habitat fragmentation with a loss of green space. Data from NASA’s Landsat and Shuttle Radar Topography Mission (SRTM) programs are employed to examine urban patterns between 1973 and 2004 for the coastal mega-city of Mumbai (formerly Bombay), India. By 2015 Mumbai is expected to be the world’s second largest city containing 22.6 million people with one of the highest population densities (UN Population Division 2006). This chapter considers the city’s ongoing and future vulnerability to flood hazards in the light of climate change models predicting an increased intensity of monsoonal storms, as well as a 0.38−0.59 m sea level rise by the end of the 21st century. Landsat MSS and ETM+ data are used to map change in urban patterns, while an unsupervised classification produces a land use map for the city and its environs. SRTM data are used to build an elevation model which is analyzed in conjunction with the land use map. Zones of vulnerability to floods are identified for the city and its environs. The results suggest that the predicted consequences of climate change will exacerbate the city’s ongoing vulnerability to flooding if urgent measures are not taken to improve storm water drainage systems and shore up other flood control defenses.