How Long is Indian Coastline?

Abstract Coastline measurements have no explicit length if they are geometrically self-similar. It is well known that length of self-similar geometrical objects is scale dependent, and hence it is not a fixed number, rather depends on the scale used to measure it. We present a definitive approach based on a fractal method to measure the coastline of India. We propose a method to define optimum scale length, that could be used to measure the coastline. Using our method, the mainland coast measures 7567 km. There are four big inhabited islands in Andaman (North, Middle, South and Little Andaman) which accounts for 687 km of island coast, and Great Nicobar Island has 195 km of coast around it, thus coastal length of inhabited islands is 882 km. Thus the total coast length of India including major 5 inhabited islands from Andaman-Nicobar group of islands is 8391 km. There are several other small islands in Andaman-Nicobar group of islands, we observed 26 of them significant in terms of their size. Indian coast length becomes 9060 km if we account for above mentioned 26 Andaman and Nicobar Islands. According to one of the Wiki articles, there are 572 islands in Andaman-Nicobar group of islands, but many of them are very small and insignificant. This is first ever scientific study about the Indian coast length, which has global significance due to strategic and climate related coastline alterations such as sea level rise due to global warming.