3.2. Geological setting
The studied area is located on the side of the youngest structural
division in the western Indo-Burman Range of the folded flank (Kresic,
2006; Nahin, Basak, Alam, & Environment, 2019). The elevation of this
area is very low from the other areas of Bangladesh. The majority of the
land is found in hilly reason. In the east boundary which is covered in
low hilly ranges (100m elevations) and west side is covered by Bay of
Bengal. Bakkhali estuary and Maheshkhali channel are found in the north
and south. The landform types of this area are divided into two
categories flooded and coastal plain. The beach plain unit has been
consisted of dunes, tidal creeks and beach. The floodplain unit has been
consisted of the Tertiary hills between the hilly reason. The flat
surface mainly consisted of sandy clay and sand size is larger in
continuously higher on the depth.