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).
Tourism and Culture. NIGERIAN CULTURE. Nigeriaâs three largest ethnic groups, the Hausa/Fulani, Yoruba, and Igbo, represent 71 percent of the population. Of the remaining 29 percent of the population, about one-third consists of groups numbering more than 1 million members each. The remaining 300-plus ethnic groups account for the final one-fifth of the population.