Geography of the Kolkata city

Geography of the Kolkata city

Geography of the Kolkata cityKolkata is located in eastern India at 22°33′N 88°20′E / 22.55°N 88.333°E in the Ganges Delta at an elevation ranging between 1.5 m (5 ft) to 9 m (30 ft). It is spread linearly along the banks of the River Hooghly in a north-south direction. Much of the city was originally a vast wetland, reclaimed over the decades to accommodate the city’s escalating population. The remaining wetland, known as East Calcutta Westland has been chosen a “wetland of international importance” under the Ramsar Convention.
Like the most of the Indo-Gangetic Plains, the predominant soil type is alluvial. Quaternary sediments consisting of clay, silt, various grades of sand and gravel underlie the city. These sediments are sandwiched between two clay beds, the lower one at depths between 250 m (820 ft) and 650 m (2,133 ft) and the upper one ranging between 10 m (33 ft) and 40 m (131 ft) in thickness. According to the Bureau of Indian Standards, the town falls under seismic zone-III, in a scale of I to V (in order of increasing proneness to earthquakes) while the wind and cyclone zoning is “very high damage risk”, according to UNDP report.
The city has a total geographical area of 1480 sq. km. The Sundarbans delta which is located at a distance of 154 km to the south of Kolkata separates the city from the Bay of Bengal. The city has been divided into different topographical regions. There are mainly five geographical units including east, west, north, south and central Kolkata. The adjoining regions include Howrah, Hooghly, North 24 Parganas, South 24 Parganas and Nadia.