Iran Geography

Flanking the desert basin are two equally imposing mountain chains, the

Alborz and the Zagros. The Alborz chain forms a relatively compact crescent

across the north of the country approximately 300 miles in length and an

average of 60 miles in width. It is dominated by the majestic snow-covered

volcanic peak of Mount Damâvand, the tallest mountain in Iran at an elevation

of 18,628 feet. On the north side, the Alborz Mountains fall away precipitously

from elevations of around 10,000 feet to the littoral of the Caspian

Sea (about 25 feet below sea level). Because of this steep drop-off and the lack

of many practicable passes, the Alborz Mountains make up a virtual wall that

effectively blocks off the Caspian area from the rest of the country. The more

complex Zagros chain consists of a broad band of parallel ranges, about 125

miles in width, running from the northwest to the southeast of the country.

The mountains of the Zagros are not quite as lofty as those of the Alborz but

are still quite impressive: the highest peak, Zardeh Kuh, rises to 14,920 feet.

The Zagros also has more practicable passes, but the layout and direction of

the individual ranges present considerable diffi culties for crossing the mountains

from east to west. In the south, the Zagros also descend fairly abruptly

from about 2,000 feet to sea level at the Persian Gulf. This combination of

mountains and a central plateau gives Iran a very high mean elevation. Most

land is above 2,000 feet, and on the central plateau, where the most important

cities are located, the average elevation is 4,000 feet.

In addition to the loftiness and ruggedness of the terrain, another important

characteristic of the geography of Iran is its aridity. The average precipitation

for the country as a whole is only 10 inches per year—not very

much considering that a desert can be defi ned as a region receiving less than

6 inches of rain per year. Moreover, this precipitation is either seasonal, falling

as snow in winter, or concentrated in a few specifi c areas, notably the

Caspian-facing slopes of the Alborz and parts of the Zagros. Areas along the

Caspian may receive 40 inches or more per year, and certain other mountain

regions perhaps half that amount. Barely half of the country receives enough

annual precipitation to exceed the marginal amount typical of a desert, and

only 10 percent of the country can be considered arable.