Explain the relationship between the establishment of early civilizations in river valleys and societal development.

Answer:

Responses may vary but should include some or all of the following information: Ancient civilizations relied on floodwaters for farming. The floods deposited silt, which enriched the soil. People built irrigation systems and drainage ditches to divert the water to the agricultural fields, which allowed them to farm year-round. Year-round farming resulted in a food surplus, which lead to increased time for societal development.