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 Federal Republic of Nigeria, commonly referred to as Nigeria /naÉªËdÊÉªÉriÉ/ , is a federal constitutional republic in West Africa, bordering Benin in the west, Chad and Cameroon in the east, and Niger in the north.t the same time, neighboring countries, Benin, Chad, Cameroon and Niger joined Nigeria in a united effort to combat Boko Haram in the aftermath of a world media highlighted kidnapping of 276 schoolgirls and the spread of Boko Haram attacks to these countries.