Analysing topographical transformation of Bombay Islands and Bombay Fort using geospatial analysis and historical records

Abstract

Mumbai is on a narrow peninsula, which lies between the Arabian Sea on the west, Thane Creek on the east and Vasai Creek on the north; consisting of two distinct regions, Mumbai City and Mumbai Suburban. The city district region or South Mumbai is also commonly referred to as the Island City, as historically this area consisted of islands separated by the sea. There were several historical fortifications dotted on these islands, such as Worli, Mahim, Sion, Sewri, Bandra and the largest of these was the Bombay Fort. The islands were combined into one landmass by man-made changes spread over a century and the ensuing land-use changes and urbanisation erased the contours of the extents of forts as well as islands. The history of the city has been a subject of interest to researchers; it is widely believed that prior to the first phase of reclamation (1711–1728 CE) there were seven islands. However, past scholarship has pointed out that the model of seven distinct islands was first introduced in a map published in 1843 CE, which retrospectively speculated the original landscape and this model has not been subjected to a scientific analysis so far (Ridings in J. Historic Geograp 59:27–39, 2018). The present study: firstly uses historical maritime cartographic records (such as sea charts, maps, birds-eye views, admiralty charts, portolan charts and pilots, made by Portuguese, French, Dutch and British) to geospatially identify and map the spatial evolution of the islands that formed the present South Bombay; secondly, traces the layout and evolution of the Bombay Fort which was the hub of power and economy of Bombay Presidency during seventeenth and eighteenth centuries and which also houses remnants of few buildings including the castle built by Portuguese.