Download Iran Sub Chapter 1 Country Location and Geography and Climate

I.R.Iran’s Geography and Climate
I.R.Iran is a Middle East country and is located between 44° 02′ E and 63° 20′ Eastern longitude and 25°
03′ N to 39° 46′ N northern latitude. Iran covers an area of about 1,648 million sq km. Its neighbors
consist of Azerbaijan, Armenia, and Turkmenistan in the north, which are around the Caspian Sea,
Afghanistan, and Pakistan in the east, and Turkey and Iraq in the west. The sea frontiers of the Persian
Gulf and Oman Sea in the south connect this country to the high seas and southern neighboring countries
of the Persian Gulf (Figure 1).
Figure 1- Political Map of Islamic Republic of Iran
The population of the country is estimated to be 70,270,000 for the year 2006. Since 1881, the country’s
population has increased from 7,7 to 65 million individuals. In other words, the annual population growth
has increased from 0.6% to 3.9% within the last 120 years. There are higher concentrations of people in
the north and west.
Tehran is the capital and the largest city. Other large cities are Mashhad, Tabriz, Isfahan and Shiraz. The
central parts of the country covered by deserts and salinas, are mainly uninhabited.
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Administrative divisions are 30 provinces: Ardebil, Azarbayjan-e-Gharbi (West Azarbayjan), Azarbayjan-eSharghi (East Azarbayjan), Bushehr, Chaharmahal va Bakhtiari, Esfahan, Fars, Gilan, Golestan, Hamedan,
Hormozgan, Ilam, Kerman, Kermanshahan, South Khorasan, Razavi Khorasan, North Khorasan, Khuzestan,
Kohgiluyeh va Buyerahmad, Kurdestan, Lorestan, Markazi, Mazandaran, Ghom, Ghazvin, Semnan, Sistan
va Balouchestan, Tehran, Yazd, Zanjan. Division of former province of Khorasan into three provinces
became effective in 2004.
About 60% of Iran is mountainous and the remaining part (1/3) is desert and arid lands. The main features
of the topography can be summarized as a great plateau, between two mountain ranges. In the north, the
Alborz Mountains have long east-west ranges of more than 2,000 meters high; these reach more than
5,000 meters in some places. In the west and southwest, the Zagros Mountains extend over a very long
distance. Most of the area is over 1800 meters; much of it is over 3,000 meters and many summits exceed
3,600 meters. The great plateau, rising one km above sea level, occupies most of the country. Some parts,
such as the Dasht-e-Lut and Sistan, are only about 500 m above the sea level. Around the Caspian Sea,
there are some narrow lands of about 20 meters below sea level.
Iran is located in a very active seismic region of the world in the junction of Arabian and Eurasia tectonic
plates. It is part of the Alp-Himalaya orogenic belt and is known as part of the youngest and last orogenic
regions of the world. Over 90% of the country is exposed to the Earthquake hazard (Figure 2).
Figure 2- Seismic hazard map of I.R.Iran
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The country is mainly arid or semi-arid. Except the northern coastal areas, the climate is extremely
continental. In summer, hot and dry weather prevails generally and in winter very cold weather is usual,
in particular in inland areas. Figure 3 shows the climatic classification of Iran into 6 levels of extremely dry,
dry, moderately dry, Mediterranean, moderately wet, wet and very wet. Furthermore, the climate of the
country can be divided into three main categories:
1.
Warm temperate, rainy with dry summer in a narrow strip in the North;
2.
Dry, hot desert in the central plateau;
3.
Dry, hot steppe covering the rest of the country.
Figure 3: Climatic Classification of Iran
Apart from the coastal areas, the temperature in Iran is extremely continental. The annual range of
temperature difference is great from 22°C to 28°C. Cold winters, especially in the north in the Alborz
Mountains are common. The January mean temperature in Mashhad is 2°C and the minimum is -25°C. On
the plateau it is less cold than in the Alborz Mountains. In summer hot weather generally prevails, in
particular, in the low land area and enclosed valleys such as those of Khuzestan and Lorestan where the
daily maximum often exceed 44°C. Summer temperatures of more than 55°C have been recorded.
The rainy period in most of the country is from November to May. The average annual rainfall is about
240 mm. Maximum amounts fall on the Alborz and Zagros slopes facing north and west respectively,
where the mean annual rainfall is more than 1,200 mm. Going inland, the ranges of precipitation
decreases to less than 100 or 50 mm annually. The amounts vary considerably with topography. In the
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northern and western mountains the annual mean precipitation is more than 480 mm, snow forms most
of the precipitation. The plateau has most of its rainfall in spring, while on the western and southern
coasts most of the rain falls in winter. On the Caspian coasts, where the rain falls earlier, the rainfall is at
its maximum in autumn. In the dry period between May and October, rain is rare in most of the country.
In other words, it seems that the temporal and spatial distribution of precipitation in Iran is volatile, as
90% of total precipitation occurs in cold and humid seasons and in northern and western parts of the
country and only 10% occurs in warm and dry seasons and in central, southern, and eastern parts. About
52% of precipitation occurs in 25% of the area of the country; hence some parts of the country will suffer
a lack of water resources and water crises in the near future (5).
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