This picture is of people living in their temporary huts with their animals. Before the discovery and invention of irrigation they were not able to live in places for too long
This picture shows the farms which they had, very little irrigation and when the soil went dry they would move to another location.
Once irrigation was implemented people were able to have more permanent living places and expand more. The animals were able to be farmed and have selective breeding creating more for the family.
Wells have been created because of more permanent living conditions, they get water from ponds, rivers and other large water sources.
Due to more permanent living conditions people are able to build barns for their animals. This meant that all of the animals were able to be fattened and bred so that more could be eaten and sold by the families.
With all of the developments people are now able to have large crops due to irrigation. This means that excess crop was common and could be sold for more money.