The higher level of levees from the adjacent areas makes a natural drainage system thas why in flood times or when it rain it fills up with water and the consistency of water in it results in bogs and swamps
Can Describe The Natural Drainage Of The Indus Delta?
The indus delta is located to the south of thatta.A delta is often triangular or fan shaped with the main distributaries branching out from the main river like the ribs of the fan.when a river flows in to the sea,its speed is soon checked and its load of alluvium is dropped on the sea floor.Deposition of alluvium on the banks of the distributaries makes the level of the levees higher than the adjacent areas.Sea water often fills up the troughs between the distributaries,resulting in swamps. The indus delta has tidal flats with mangrove swamps.The coastal area is generally low and flat.