CHANGES IN WETLANDS IN DHAKA CITY: TRENDS AND PHYSICO-ENVIRONMENTAL CONSEQUENCES
This study makes an attempt to identify the urban wetlands, emphasizing on the extent of their changes and subsequent impacts on physical environment of the area. For ascertaining the land-use pattern of the City, this study uses topographical map (Toposheet of 1960) and satellite images (Landsat TM, 1988 and ALOS VNIR, 2008). It also uses remote sensing and GIS based software (e.g. Arc GIS, Erdas Imagine) for this purpose. Statistical analysis has been carried out in order to process and analyze the data. The study observes that the wetlands of Dhaka city are changing very quickly. In 1960, the total area of water bodies and lowlands were 2952.02 and 13527.58 ha, respectively. Whereas in 1988, the total area of the same decreased to 2103.62
and 12717.73 ha, respectively.This changing trend of wetlands makes the drainage system of Dhaka City vulnerable, creating water logging problems and their consequences.