The hilly areas of the northeast and southeast are occupied by much smaller tribal groups, many of which have strongly resisted domination by the national government and the population pressure from Bangladeshis who move into and attempt to settle in their traditional areas.
In 1998 an accord was reached between the armed tribal group Shanti Bahini and the government. Bangladesh is the most densely populated nonisland nation in the world.
About half the total area is actively deltaic and is prone to flooding in the monsoon season from May through September.
Girls between one and four years of age are almost twice as likely as boys to die.
In the early 1980s the annual rate of population increase was above 2.5 percent, but in the late 1990s it decreased to 1.9 percent.
The Chittagong Hill Tracts have extensive hardwood forests.
The vast river delta area is home to the dominant plains culture.
Green symbolizes the trees and fields of the countryside; red represents the rising sun and the blood spilled in the 1971 war for liberation.