The term is desertification.
Desertification
When contour lines are farther apart, it indicates a gentle slope or gradual change in elevation in the terrain. This means the change in elevation over a given distance is more gradual.
The name given to the gradual warming of the Earth is "Global Warming."
Given the river is over 4,000 miles long and flows through all kinds of landscape, from jungle to desert, it is impossible to calculate.
Can produce fertile offspring.
The largest desert in Australia is the Great Victoria Desert.
Global warming is the name given to the recent (over 200 years) gradual increase in the temperature of Earth's atmosphere.
Given the Nile is over 4,000 miles long it is impossible to answer this question exactly, however it would cover life-styles conducive to jungle to desert to villages to towns to cities.
The fertile crescent.
Gen Rommel
The ship of the desert
the Desert Ratsthe Desert Rats