Final answer:
The fertile soil of the Nile River valley, enriched by predictable floods, enabled ancient Egyptians to practice sustainable agriculture, produce surplus crops, and settle permanently, helping their civilization to flourish.
Step-by-step explanation:
The fertile soil of the Nile River valley dramatically changed the way ancient Egyptians obtained food. The predictability of the Nile River's flooding provided a means of controlled irrigation, making the soil rich with nutrients and suitable for agriculture. As a result, ancient Egyptians could settle in one place, produce surplus crops, and nurture a burgeoning population. They learned to control the flow of water through intricate irrigation systems, allowing long-term farming on the same lands.
The Nile Valley, known as "Kemet" or the Black Land to Egyptians, was exceptionally fertile, leading to harvests up to three times more bountiful than in other regions. This agricultural productivity facilitated a surplus generating wealth for the royal government through taxes and redistribution.