Abstract for presentation at The 13th Australasian Remote Sensing and Photogrammetry Conference

During the last decade Dhaka, the capital city of Bangladesh got flooded even in moderate rainfall. Jamming of the city drainage system due to discarding of shopping polythene-bags was identified as one of the main causes for such flooding. Accordingly, on January 2002 the sale and use of polythene bags were banned in Capital City Dhaka by the Bangladesh Government, followed by a nation wide ban went into effect from March 2002. Now the obvious question is: how this banning of polythene bags helped in reducing flood disaster in Dhaka City? Are there other reasons for such water logging problem? In order to know the answer to these questions, this study aims to undertake a modest attempt to find the cause(s) of water logging problem in Dhaka City by applying satellite remote sensing and economic valuation tool: the contingent valuation method (CVM). Accordingly, a total of 1050 households had been interviewed covering all the areas of Dhaka City to find the economic value of the decision to ban polyphone bags. Also, we have examined the land cover changes by satellite images of LANDSAT-4 and 7 to quantify the water area lost during the period of 1989 to 2003.
The results of the study indicated that, polythene bags are largely blamed by the citizens as the cause for water logging problem in Dhaka City. However, land cover changes form the satellite remote sensing image analysis showed that filling of water areas and low lands are also causing water logging problem in Dhaka City. Finally, this study concluded that, not only polythene bags, but also quick replenishment of water reservoirs in Dhaka City due to unplanned urban development is also one of the main reasons for increasing water logging problem in Dhaka City.