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).
The remaining 300-plus ethnic groups account for the final one-fifth of the population. The Hausa, concentrated in the far north and in the Republic of Niger, are the largest of Nigeria s ethnic nations. Most Hausa are Muslims engaged in agriculture, commerce, and small-scale industry.While most live in smaller towns and villages, others occupy several larger indigenous cities.he remaining 300-plus ethnic groups account for the final one-fifth of the population. The Hausa, concentrated in the far north and in the Republic of Niger, are the largest of Nigeria s ethnic nations. Most Hausa are Muslims engaged in agriculture, commerce, and small-scale industry.