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).
Yoruba. The Yoruba are one of Nigeriaâs most urban ethnic groups. Historically, their culture centered on densely populated city-states each controlled by an oba, or king. Yoruba now form the majority in Lagos, the second most populous city in Africa.gbo. The Igbo, the main ethnic group in southeastern Nigeria, has represented some of the staunchest opponents of Sharia law. In many northern Hausa-Fulani-dominated states, minority populations of Igbo claim to have been unfairly targeted by laws that do not pertain to their faith.