View Full Document. Ultimate base level for all rivers is sea level - Longitudinal profile: way to show a riverâs overall vertical drop. Shows the elevation of its channel bottom from the headwater areas to its downstream termination (the riverâs mouth).
The population is as diverse as it is large, with some 250 ethnic groups. Nigeria's three largest ethnic groups are: Hausa-Fulani (29 percent of the population), Yoruba (21 percent) and Igbo, or Ibo (18 percent).he population is as diverse as it is large, with some 250 ethnic groups. Nigeria's three largest ethnic groups are: Hausa-Fulani (29 percent of the population), Yoruba (21 percent) and Igbo, or Ibo (18 percent).
Map. Located in West Africa, Nigeria is the population giant of Africa, with more than 130 million people. The terrain changes from the oil-rich Niger Delta in the south to a belt of rain forests inland and to high savanna-covered plateaus in the north.ap. Located in West Africa, Nigeria is the population giant of Africa, with more than 130 million people. The terrain changes from the oil-rich Niger Delta in the south to a belt of rain forests inland and to high savanna-covered plateaus in the north.