Study on the approaches to residential development in lowlands of the peri-urban areas of Dhaka city

Abstract

Bangladesh is located within the world’s largest Ganges-Brahmaputra Delta and the unique relation between land and water is quite evident throughout the landscape of the country. Yet for the development of its capital, Dhaka city, its unique natural landscapes and its dynamics is quite often neglected. Available land of the city core area being filled up, the city has been stretching towards its periphery often by unplanned and unguided sandfilling the lowlands and wetlands of the existing watershed area. As a result of increasing impermeable surfaces resulting from such filling activities, degraded hydrologic conditions are increasing. The city is suffering from as a number of negative environmental consequences. Increasing flood vulnerability, impact of climate change, loss of habitat and water pollution are among the negative impacts. The existing natural wetlands need to be preserved and lost wetlands need to be restored by introducing constructed wetlands, to face the challenges the city. For the preservation and restoration process along with the residential development, the functions of wetlands need to be analyzed and retained as far as possible. In this research, first stage of work involved mapping of categorized watersheds of Dhaka region to observe the current conditions and for identifying a study area in the periphery of Dhaka City. The field study analyzed the existing conditions of the area. GIS (Geographic Information System) and Remote Sensing methods were applied as tools for this mapping. The research produced indicative design strategies as an outcome of the mapping study and field study. In order to limit the impact on the watershed general design strategies for the regional scale and indicative design strategies for the neighborhood scale have been presented. Finally design strategies pertaining to building scale have been presented that help adapt to the natural dynamics of its surrounding.