One look at the relief map of Israel instantly explains so much. This time: The Judean Desert – a "Rain Shadow Desert."

Most of Israel’s territory is desert (about 60%!), which includes the Negev in the south and the Judean Desert in the east. Definition of a desert: an area where annual precipitation is less than 200 mm.

The Negev is part of the global desert belt – those vast desert zones lying north and south of the equator, which include, among others, the Negev, the Sinai Desert, and the Sahara Desert.

The Judean Desert, on the other hand, was formed due to the area’s geographic and topographic structure, and it represents a phenomenon called a "rain shadow desert."

Clouds arriving in Israel from the west climb eastward. As elevation increases, air pressure decreases; during this ascent, the air cools, moisture condenses, and rain clouds form (or, as people say, it rains).

Beyond the watershed line, the cliff is dramatic: in a very short span there is a steep drop of about 1,200 meters—from 800 m above sea level to 400 m below sea level. The clouds plunge sharply downward, the air warms up, and the remaining moisture in the clouds evaporates. As a result, rainfall on the eastern slope—what is in fact the Judean Desert—is extremely scarce. And just like that: a desert is formed.

Illustrations:

1 – Relief map of Israel

2 – Relief map of the Judean Desert area, illustrating the creation of a "rain shadow desert"

3 – A nice diagram that also helps explain (Diagram: Wikipedia)