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).
YORÃ¹BÃ¡ PEOPLE AND CULTURE. The YorÃ¹bÃ¡ people are a near-homogenous and semi-independent peoples loosely linked by geography, language, history, culture and religion. YorÃ¹bÃ¡ communities can be found in different parts of West Africa but the largest concentration can be found in the Southwestern part of Nigeria.