Recent Climatic Changes in Some Selected Cities in Bangladesh – A case study on Sylhet (pp. 139-154)
Authors: (Jahir Bin Alam, Sirajul Islam and Rezaul Kabir Chowdhury)
Abstract: Urbanization trend in the present world is increasing at an unprecedented rate, especially in the developing countries. In Bangladesh, along with global climate change, local effect like high population growth, unplanned industrialization, destruction of natural ecosystem and topography, etc leading to change in urban climate at an even faster rate. This study investigated the changes in climatic parameters viz. annual mean temperature, annual total rainfall and annual mean humidity of four divisional cities in Bangladesh Dhaka, Chittagong, Rajshahi and Sylhet. Primary data of several climatic parameters have been collected from Bangladesh Meteorological Department for the period as Dhaka (1960-1999), Chittagong (1950-1999), Rajshahi (1964-1999) and Sylhet (1957-1999). Average value of the entire period, average of ten year‘s value and five-year running average value of each parameter have been plotted against corresponding year. It has been found that annual mean temperature has an increasing trend for all the cities. Annual total rainfall has decreasing trend for all the cities except Dhaka. Annual mean humidity of Dhaka city has decreasing trend during 1960-1980 and increasing trend during 1980-1990. For Rajshahi and Sylhet city, it has increasing trend, whereas for Chittagong city it has decreasing trend. A number of factors affected the changes are global climate change, high growth rate and destruction of local topography.