Symposium on Remote Sensing tor Resources Development and Environmental Management / Enschede / August 1986 
779 
Satellite remote sensing of the coastal environment of Bombay 
V.Subramanyan 
Indian Institute of Technology, Bombay 
ABSTRACT: Remote sensing of the coastal environment of Bombay using the Landsat imagery 
(black and white and false-colour paper prints) makes it possible to trace the development 
and evolution of the coast. The coast is indented by many bays, promontories, creeks, tidal 
mudflats, stacks and beaches. It is thus one of rétrogradation. All the creeks follow 
lineaments and there is a triple junction of such lineaments to the east of Bombay. These 
clearly indicate the erosional development of the region by fluvio-marine processes. A 
reconstruction of the initial configuration of the Bombay region is attempted. Marshes, 
raised beaches and littoral concrete point to the emergence of the region in the past. 
The bays and headlands will be eliminated towards the end of the current marine cycle and 
the coast, straightened. Three rows of cuestas of volcanic rocks trending NNE-SSW with 
westerly dipslopes traverse the island lengthwise; there are three aligned lakes. 
1 INTRODUCTION 
The Bombay coast, including that of the 
Salsette island to the north, forms a part 
of the Konkan Coast of the West Coast phy 
siographic division (National Atlas 1964)** 
The geomorphic environment of this coastal 
tract and the neighbouring Nhava-Sheva-Uran 
shoreline to the east was studied using the 
following data products of the Landsat: 
black and white paper print on MSS band 6 
on the scale of 1:250,000 and false-colour 
composite paper print on MSS bands 4 (yel 
low) , 5 (pink) and 7 (blue) on the scale 
of 1:500,000. The images were further mag 
nified during the visual interpretation. 
Geological and geomorphological field 
traverses were undertaken in selected loca 
lities for the collection of ground truth. 
The topographical maps on the scale of 1: 
63360 and the Town Guide Map of Bombay on 
the scale of 1:25,000 were also consulted 
for supplementary data. 
2 SATELLITE DATA 
The black and white image brings out clear 
ly the configuration of the Bombay-Salsette 
coast and the Nhava-Sheva-Uran coast to the 
east. Three well-developed bays, namely, 
the Manori bay, the Mahim bay and the Back- 
bay and the broad embayment between Versova 
and Juhu show up along with their corres 
ponding promontories (Fig.1). Sandy beaches 
can be readily recognised by the white tone 
around Manori, Versova, Juhu, Bandra and 
Girgaon. Rocky beaches with boulders, cobb 
les and gravels as well as wave-cut plat 
forms can be identified at other places 
along the coast by the pale grey tone. The 
cuestas bordering the three lakes and con 
tinuing farther north display a light and 
shade effect on their escarpments and dip- 
slopes. The morphological signature of the 
cuestas south of the Powai lake is a faint 
grey line whereas in the Kanheri Hills in 
the northern part of the island, the cues 
tas occupy a considerable area - about 25 
sq. km. The big c uesta at the centre of the 
Figure 1. A Landsat view of the 
Bombay-Salsette island and the 
neighbouring country to the east 
and southeast on MSS hand 6. The 
coastal and inland features show 
up very well. 
Trombay island in the east also shows up as 
a thick grey line. The mudflats that have 
formed in the tidal zone between the low 
and the high tides are readily recognised 
by their dark grey tone and their locations 
around the creeks. The lakes and the creeks 
appear black whereas the marshes in the 
Mahim and Chembur areas appear as medium 
grey patches. 
The basalts are seen as pale grey areas 
in the Bombay island while the trachytes, 
rhyolites and tuffs in the Salsette island 
appear much paler. The salt fields have 
registered themselves as white streaks, ex 
pectedly. The urban, suburban and vegetated 
areas show a light grey tone. 
The false-colour composite facilitates the