Explain how rivers and waterways promoted settlement and migration

Answer 1

If one looks at any map, they will see that the vast majority of cities are present in two general locations: either they are along the coastlines of oceans or they are along the banks of rivers. Why?

To begin with, human beings and their sources of food - crops and domesticated animals - need fresh water (and, yes, I know that the oceans are filled with salt water, so this doesn't apply to cities located on ocean coastlines...). While it's true that rainfall can serve as an alternative source of fresh water, it is rainfall that produces rivers and other waterways (rainfall + higher to lower ground + gravity = rivers, streams, creeks, etc...) Rivers and other waterways provide more than enough fresh water for humans to drink and to use for other purposes, including providing drinking water for domesticated animals (cows, sheep, goats, etc...) and for thirsty crops, both of which, in turn, provide another human necessity, food (not to mention other items, such as wool and cotton).

Rivers and other waterways serve another important purpose for humans. With the use of vessels of some sort, from canoes to rafts, from barges to ships, rivers and other waterways provide a means of relatively easy movement - certainly faster and easier that moving across the land (not that rivers and waterways are perfect routes for movement - their are obstacles such as rapids and waterfalls, and the water level can be too low for a vessel to float on...) This, by the way, is also the reason for the presence of so many cities on the coastlines of oceans.

Using vessels of some sort, humans and their possessions / goods can move from one location to another. Humans can migrate from an existing settlement, traveling along the route of a river or other waterway, to a new location to begin an entirely new settlement. Because using vessels of some sort on a river or other waterway is the easiest and cheapest way to transport goods - even today, it still is - rivers and other waterways have become routes for trade. And, in turn, the opportunities to engage in trade have made settlement along rivers and other waterways desirable among humans.