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).
Nigeria is a federal republic modeled after the United States, with executive power exercised by the president. The government of Nigeria is also influenced by the Westminster System model in the composition and management of the upper and lower houses of a bicameral legislature.The president, however, is the head of state, the head of government, and the head of a multi-party system.Nigerian politics takes place within a framework of a federal, presidential, representative democratic republic, in which executive power is exercised by the government.egislative power is held by the government and the two chambers of the legislature: the House of Representatives and the Senate. Together, the two chambers make up the law-making body in Nigeria, called the National Assembly, which serves as a check on the executive arm of government.