Flood risk of natural and embanked landscapes on the Ganges-Brahmaputra tidal delta
Carbonate-rich sabkha and supratidal to subtidal carbonate tidal-flat sediments were deposited in the northern and northwestern part and silt- and sand-rich tidal delta
deposition in the southern and southwestern part of the DBB.
SPELL OF THE TIGER: THE MAN-EATERS OF SUNDARBANS introduces readers to a mangrove swamp and tidal delta
that lies between India and Bangladesh: the only place on earth where tigers routinely eat people.
Former flood-tide delta forms compose the broad shelf along the estuarine margin of the barrier spit, and subsequent reworking of the tidal delta d~ posits has altered most of their channel morphologies.
There are deep channels along the margins of the tidal delta through which there is a counterclockwise tidal current circulation (Psuty et a1.2).
Most of the shoal surface of the tidal delta as well as the shallow shelf along the inland margin of the barrier is medium sand.
The predominant drift direction in the area is to the south, as evidenced by the down-drift asymmetry of the ebb tidal delta in the direction of storm-induced longshore currents (Seabergh et al., 1998).
Because of the severity of the breach at Little Bay and the potential seriousness of its environmental impact on wetlands and aquatic habitat in the region, the USAGE (1997) has implemented a plan to remediate the problem, which entails the placement of sand-filled geotextile containers (geotubes with a maximum length of [sim]65 m per section) across the flood tidal delta at the north channel to close the breach, limit shoreline erosion, and preclude the reformation of the breach during the 30-year design life of the project.
Simultaneously, the inlet located at the western side of the Mundaka sand bar (zone 3) became deeper and the previous tidal delta
at the mouth of the new (anomalous) inlet channel disappeared (zone 4).
In a general way, we can observe that the values of velocity are higher during the flood ebb than during the flood, in the inner system, whereas in the flood tidal deltas and spill-over lobes (Bay and Mouth complex) the dominant current is the flood.
These flood tidal deltas and lobes are also formed by well sorted fine sand and flood oriented medium 2D and 3D dunes have been observed.
Lower currents have caused morphological changes in the tidal deltas
at its mouth, which at present are developing front lobes closer to the shoreline as well as shallower tidal-channels as a result of the greater influence of swell in the swell-tide balance.