The Ganges River Crossing the Lower Gangetic Plain, Bangladesh23.8N 89.2E
The Ganges and its tributaries drain a 1,000,000-square-kilometre (390,000 sq mi) fertile basin that supports one of the world’s highest density of human beings.
Roughly 80 % of Bangladesh’s landmass is made up of fertile alluvial lowland called the Bangladesh Plain. The plain is part of the larger Plain of Bengal, which is sometimes called the Lower Gangetic Plain.
Although altitudes up to 105 meters above sea level occur in the northern part of the plain, most elevations are less than 10 meters above sea level; elevations decrease in the coastal south, where the terrain is generally at sea level.
With such low elevations and numerous rivers, water—and concomitant flooding—is a predominant physical feature. About 10,000 square kilometers of the total area of Bangladesh is covered with water, and larger areas are routinely flooded during the monsoon season.