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Iran
Topography
Iran consists of rugged, mountainous rims surrounding high interior
basins. The main mountain chain is the Zagros Mountains, a series
of parallel ridges interspersed with plains that bisect the country
from northwest to southeast. Many peaks in the Zagros exceed 3,000
meters above sea level, and in the south-central region of the
country there are at least five peaks that are over 4,000 meters.
As the Zagros continue into southeastern Iran, the average elevation
of the peaks declines dramatically to under 1,500 meters. Rimming
the Caspian Sea littoral is another chain of mountains, the narrow
but high Alborz Mountains. Volcanic Mount Damavand (5,600 meters),
located in the center of the Alborz, is not only the country's
highest peak but also the highest mountain on the Eurasian landmass
west of the Hindu Kush .
The center of Iran consists of several closed basins that collectively
are referred to as the Central Plateau. The average elevation
of this plateau is about 900 meters, but several of the mountains
that tower over the plateau exceed 3,000 meters. The eastern part
of the plateau is covered by two salt deserts, the Dasht-e Kavir
and the Dasht-e Lut. Except for some scattered oases, these deserts
are uninhabited.
Iran has only two expanses of lowlands: the Khuzestan plain in
the southwest and the Caspian Sea coastal plain in the north.
The former is a roughly triangular-shaped extension of the Mesopotamia
plain and averages about 160 kilometers in width. It extends for
about 120 kilometers inland, barely rising a few meters above
sea level, then meets abruptly with the first foothills of the
Zagros. Much of the Khuzestan plain is covered with marshes. The
Caspian plain is both longer and narrower. It extends for some
640 kilometers along the Caspian shore, but its widest point is
less than 50 kilometers, while at some places less than 2 kilometers
separate the shore from the Alborz foothills. The Persian Gulf
coast south of Khuzestan and the Gulf of Oman coast have no real
plains because the Zagros in these areas come right down to the
shore.
There are no major rivers in the country. Of the small rivers
and streams, the only one that is navigable is the Karun, which
shallow- draft boats can negotiate from Khorramshahr to Ahvaz,
a distance of about 180 kilometers. Several other permanent rivers
and streams also drain into the Persian Gulf, while a number of
small rivers that originate in the northwestern Zagros or Alborz
drain into the Caspian Sea. On the Central Plateau, numerous rivers,
most of which have dry beds for the greater part of the year,
form from snow melting in the mountains during the spring and
flow through permanent channels, draining eventually into salt
lakes that also tend to dry up during the summer months. There
is a permanent salt lake, Lake Urmia (the traditional name, also
cited as Lake Urmiyeh, to which it has reverted after being called
Lake Rezaiyeh under Mohammad Reza Shah), in the northwest, whose
brine content is too high to support fish or most other forms
of aquatic life. There are also several connected salt lakes along
the Iran-Afghanistan border in the province of Baluchestan va
Sistan.
Data as of December 1987
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