How does a river change the land as it flows upstream?

Answer 1

Two main ways a river might change the land around it would be to erode the surrounding landscape (like how the Colorado River formed the Grand Canyon) and to fertilize the soil around it (like the Nile river).

Answer 2

A river flows downstream, and can erode the banks, deposit gravel, sand and silt lower down, meander in the lower levels, cause loss of life, destroy property and farm crops, etc. when in flood.