Geography 100 River Basin Essay

I need an explanation for this Geography question to help me study.

Your Paper should be three to four text-written pages, plus one page of endnotes and one page that shows a map of the river basin. You may have only a few endnotes, two or three. Your paper should be typed and double-spaced (1.5). The final page (not counted as part of the four pages) should have “endnotes”. The citations of sources used in your paper. The one source you must use is your textbook. See the required reading below.