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).
Nigeria is in West Africa, along the eastern coast of the Gulf of Guinea, and just north of the equator. It is bordered on the west by Benin, on the north by Niger and Chad, and on the east by Cameroon. Nigeria covers an area of 356,669 square miles (923,768 square kilometers), or about twice the size of California.he referred to the area as Nigeria, after the Niger River, which dominates much of the country's landscape. The word niger is Latin for black. More than 250 ethnic tribes call present-day Nigeria home. The three largest and most dominant ethnic groups are the Hausa, Yoruba, and Igbo (pronounced ee-bo).