What Is an Oasis?

Oasis in desert
Istvan Kadar Photography Getty

An oasis is a lush green area in the midst of a desert, centered around a natural spring or a well. It is almost a reverse island, in a sense, because it is a tiny area of water surrounded by a sea of sand or rock.

Oases can be fairly easy to spot — at least in deserts that do not have towering sand dunes.  In many cases, the oasis will be the only place where trees such as date palms grow for miles around.

The sight of the speck of green of an oasis on the horizon has been a very welcome one for desert travelers for centuries!

Scientific Explanation

It seems amazing that trees could sprout in an oasis. Where do the seeds come from? As it happens, scientists believe that migrating birds spot the glint of water from the air and swoop down for a drink. Any seeds that they happen to have swallowed earlier will be deposited in the damp sand around the water hole, and those seeds that are hardy enough will sprout, providing the oasis with its tell-tale splash of color amidst the sand.

Caravans in desert areas such as Africa's Sahara or the dry regions of Central Asia have long depended on each oasis for food and water, both for the camels and their drivers, during difficult desert crossings. Today, some pastoral peoples in western Africa still depend on oases to keep themselves and their livestock alive between different grazing areas that are interrupted by desert.

In addition, many kinds of desert-adapted wildlife will seek water and also take shelter from the blazing sun in the local oasis.

Historical Significance

Historically, many of the major cities of the Silk Road sprang up around oases, such as Samarkand (now in Uzbekistan), Merv (Turkmenistan) and Yarkand (Xinjiang).

In such cases, of course, the spring or well could not be some mere trickle — it had to be almost a subterranean river in order to support a large permanent population, plus travelers. In a few cases, like that of Turpan, also in Xinjiang, the oasis was even large enough to support irrigation works and local agriculture.

Smaller oases in Asia might support only a caravanserai, which was essentially a hotel and tea house set out along the desert trade routes. Generally, these establishments were fairly isolated and had very small permanent populations.

Word Origins and Modern Usage

The term "oasis" comes from the Egyptian word "wh't," which later evolved into the Coptic term "ouahe.The Greeks then borrowed the Coptic word, reworking it into "oasis." Some scholars believe that the Greek historian Herodotus was actually the first person to borrow this word from Egypt. In any case, the word must have had an exotic flavor to it even back in ancient Greek times, since Greece does not have expansive deserts or oases among its landforms.

Because an oasis is such a welcome sight and a haven for desert travelers, the word is now used in English to indicate any sort of relaxing stopping point — particularly pubs and bars, with their promise of liquid refreshments.

There's even a California band by the name whose songs are a tongue-in-cheek statement of that sentiment.