How Oases Actually Work

An oasis is a fertile desert area sustaining plants and animals. Surface water may be present or accessed from deep wells.

Rain showers provide subterranean water for natural oases like the Tuat. Bird droppings are just aerial landscaping.

In Oman, aflaj tunnel systems tap underground aquifers below plateaus. This rainwater harvesting system avoided serious salinity problems.

Date palms form the upper layer. They provide shade for smaller understory trees.

Measurements show evapotranspiration in an oasis dropped 30 to 50 percent. Trees run their own air conditioning.

Oasis ecosystem covers a tiny fraction of Earth's surface.

Oases in West Asia and North Africa cover about 1,000,000 hectares. They support about 10 million inhabitants.

A 1920 guide warned springs are often clogged with gravel or rubbish. Travelers needed a shovel.