Study Area

The Meghna Basin comprises eight districts in the northeastern portion of Bangladesh, specifically Sylhet, Sunamganj, Netrokona, Mymensingh, Moulvi Bazar, Kishorganj, Brahmanbaria, and Habiganj, together with the North Eastern region of India. The approximate land area of Bangladesh within the basin is estimated to be around 24,500 square kilometers. According to the 2011 national census of Bangladesh, the population living in this specific region is expected to be over 25,800,000 people. The region is surrounded by steep terrain situated to the north and west of India. The presence of orographic precipitation in this area can be linked to the sudden change in elevation from Bangladesh to India. Additionally, the depression basins situated in the middle of the Meghna basin covering Sunamganj, Netrokona, and part of Mymensingh districts have the elevation closer to the mean sea level as indicated in Figure 1-1 which favors the formation of large storage of rainwater in the monsoon and pre-monsoon season. The monsoon wind originating from the Bay of Bengal contains a significant amount of moisture. When this wind reaches the hilly areas of Meghalaya, the moisture condenses and results in heavy precipitation. This, in turn, creates severe flash floods in the downstream region of Bangladesh. The extent of the Meghna basin is illustrated in Figure 1.