Answer:
A river forms from water moving from a higher elevation to a lower elevation, all due to gravity. When rain falls on the land, it either seeps into the ground or becomes runoff, which flows downhill into rivers and lakes, on its journey towards the seas.
I would say that the main problem affecting North Africa and SW Asia would most likely be water or the scarcity of it assuming that North Africa would include places like the Sahara Desert and also the south of India which I believe is quite arid..
The divide is a ridge in the rocky mountains hence divides the waterways from the west to flow westwards to the Pacific and then the waterways from the east to flow eastern to the Atlantic. Divides the flow of water and no water can disobey this line
Answer:
It adds more water to the main river by bring in new water from a different source
Explanation:
more tributaries=larger amount of water
