How do the natural conditions of the two rivers differ from the natural conditions of ancient Egypt?

The Mesopotamia had clayey soils. Their rivers had an unpredictable flow. After snowmelt in the mountains and heavy rainfall, the rivers often changed their course. People and livestock were killed. Structures collapsed. After the water receded, swamps formed. Part of the land was flooded with swamps, in which harmful bacteria and parasites multiplied. The flow of the Nile River in Egypt was calm and predictable. The alluvial silt provided soil fertility. The Egyptians reaped bountiful harvests. But Egypt was cut off by the features of the relief from the other world. This explains some of the backwardness.