Answer:
floods
Step-by-step explanation:
River Nile is full of rich soil that is very good for farming and very fertile. Heavy rainfalls in Egypt usually happen in the wintertime, and then the river Nile floods out of its bank. Not only this way the earth around the bank is watered, but the soil gets enriched by the nutrients and minerals of the soil and becomes more fertile.
This river goes all the way through Egypt, from north to south, and is one of the main water sources in the country. This is why ever since ancient times, annual floods of the river Nile have been crucial for Egypt. The rainfalls and floods are supporters of life in Egypt ever since a few thousand years ago.