How might this population suddenly increase? How might this affect the ecosystem? (For Sloths in Tropical rainforest)

To solve their problems, mesopotamians used irrigation, a way of supplying water to an area of land. to irrigate their land, they dug out large storafe basins to hold water supplies these ditches brought water to the feilds. to protect their feilds from flooding, farmers built up the banks of the tigris and euphrates.hope ths !

I'm going to go with 1,982 feet because of all of the ice.                                               ps its this is not the answer go with d 6,500.