Why is river city called river city?

What was the effect of irrigation on the Aral sea? What name do geographers give to a region of rich soil that stretches between the Persian Gulf and the Mediterranean Sea? What is the tallest water-fall in Madagascar? What are the disadvantages of tourism in Gambia? What African countries have rain forests? What kind of whale is the pacific life whale? Were The leading production areas in the US the Middle Atlantic and North Central states? What do you call where a road crosses a river? What is the size of the Big Ben? Was building Kielder reservoir successful? Was the akosombo dam a success of a failure? What was the name of the aircraft that carried Lindbergh across the Atlantic Ocean? What does an automated lighthouse do? What are the 5 rivers over 1000 miles long that have the same names of the US states? Where does the river siene start and end? The country in which river Wangchu flows is? What national park start with the letter q? Is Gaumukh the origin of Brahmaputra river? How Giza build? What would you lose if you lost coral reefs?