Assessment of adaptation measures against flooding in the city of Dhaka, Bangladesh

Dhaka is one of the world’s largest megacities with a high rate of urbanization. Due to the setting of greater Dhaka in a deltaic plain, it is extremely prone to detrimental flooding. Risks associated with flood are expected to increase in the coming years because of the global climate change impacts as well as the high rate of urbanization the city is facing. The low lying part of Dhaka (Dhaka East) faces most severe risk of flooding. Traditionally, this part has been efficiently storing the excess water caused by excessive rainfall and the canals connected to the rivers gradually drained the water to the rivers. But the alarmingly increasing population of Dhaka is leading towards the encroachment of these water retention areas because of the land scarcity. The natural drainage for the city is not performing well and the area is still unprotected from flooding, which causes major threats to its inhabitants. This situation increases the urgency to effectively adapt to current floods caused by climate variability and to the impacts of future climate changes. The government is planning several adaptive measures to protect the area whereas a systematic framework to analyze and assess them is lacking. The objective of the paper is to develop an integrated framework for the assessment of various (current and potential) adaptation measures aimed at protecting vulnerable areas from flooding. The study firstly assesses current and future risks from flooding in the most sensitive region of the city. Subsequently, the study identifies, analyses and assesses adaptive initiatives and measures to address flood risks in the Eastern fringe area. Adaptation assessment is conducted within the framework of Multi Criteria Analysis methodology which allows both normative judgment and technical expertise in the assessment process. Based on the assessment and analysis, adaptive measures are prioritized to enable more effective action. Such a participatory integrated assessment of adaptation options is a new approach in flood management in least developed countries and in Bangladesh in particular. A framework for prioritization of adaptation measures is lacking in the decision making process in Bangladesh which could immensely assist in informed and structured decisions while developing adaptation strategies.