Mountains The Zagros range stretches from the border with the Republic of Armenia in the north-west to the Persian Gulf, and then eastward into Baluchistan. As it moves southward, it broadens into a 125-mile-wide band of parallel, alternating mountains lying between the plains of Mesopotamia and the great central plateau of Iran. It is drained on the west by streams that cut deep, narrow gorges and water fertile valleys. The land is extremely hard, difficult to access, and populated largely by pastoral nomads.
The Alborz mountain range, narrower than the Zagros but equally forbidding, runs along the Zagros but equally forbidding, runs along the southern shore of the Caspian to meet the border ranges of Khorassan to the east. The highest of its volcanic peaks is 18,600-foot, snow-covered Mt. Damavand. On the border of Afghanistan, the mountains fall away, to be replaced by barren sand dunes.
The arid interior plateau, which extends into Central Asia, is cut by two smaller mountain ranges. Parts of this desert region, known as dasht, are covered by loose stones and sand, gradually merging into fertile soil on the hillsides. Where fresh water can be held, oases have existed from time immemorial, marking the ancient caravan routes. The most remarkable feature of the plateau is a salt waste 200 miles long and half as wide, knows as the kavir (deserts). It remains unexplored, since its treacherous crust has been formed by large, sharp-edged salt masses which cover mud. Cut by deep ravines, it is virtually impenetrable.
Deserts The vast deserts of Iran stretch across the plateau from the north-west, close to Tehran and Qom, for a distance of about 400 miles to the south-east and beyond the frontier. Approximately one-sixth of the total area of Iran is barren desert.
The two largest desert areas are known as the Kavir-e-Lut and the Dasht-e-Kavir. Third in size of these deserts is the Jazmurian. It is often said that the Kavir-e-Lut and Dasht-e-Kavir are impossible to cross except by the single road which runs from Yazd to Ferdows, but in recent years, heavy trucks and other vehicles have travelled over long stretches of these deserts which contain extensive mineral deposits -chlorides, sulphates and carbonates - and it is only a matter of time before they are exploited.
Other Lakes. Along the frontier between Iran and Afghanistan there are several marshy lakes which expand and contract according to the season of the year. The largest of these, the Seestan (Hamun-Sabari), in the north of the Seestan &Y Baluchistan province, is alive with wild fowl.
Real fresh water lakes are exceedingly rare in Iran. There probably are no more than 10 lakes in the whole country, most of them brackish and small in size. The largest are: Lake Urmiya (area: 3,900-6,000 sq. km. depending on season) in Western Azerbaijan, Namak (1,806 sq. km.) in the Central province, Bakhtegan (750 sq. km.) in Fars province, Tasht (442 sq. km.) in fars province, Moharloo (208 sq. km.) in Fars province, Howz Soltan (106.5 sq. km.) in Central province.
The Persian Gulf. The Persian Gulf is the shallow marginal part of the Indian ocean that lies between the Arabian Peninsula and south-east Iran. The sea has an area of 240,000 square kilometres. Its length is 990 kilometres, and its width varies from a maximum of 338 kilometres to a minimum of 55 kilometres in the Strait of Hormuz. It is bordered on the north, north-east and east by Iran, on the north-west by Iraq and Kuwait, on the west and south-west by Saudi Arabia, Bahrain and Qatar, and on the south and south-east by the United Arab Emirates and partly Oman. The term Persian Gulf is often used to refer not only proper to the Persian Gulf but also to its outlets, the Strait of Hormuz and the Gulf of Oman, which open into the Arabian Sea.
The most important islands of the Persian Gulf on the Iranian side are: Minoo, Kharg, Sheikh Saas, Sheikh Sho'ayb, Hendurabi, Kish, Farur, Sirri, Abu Mussa, the Greater and Lesser Tunb Qeshm, Hengam, Larak, Farsi, Hormuz, Lavan, The notable ports on the Persian Gulf coast are: Abadan, Khorramshahr, Bandar Iman Khomeini, Mahshahr, Deilam, Gonaveh, Rig, Bushehr, Bandar Lengeh, Bandar Abbas.
The Iranian shore is mountainous, and there are often cliffs; elsewhere a narrow coastal plain with beaches, intertidal flats, and small estuaries borders the gulf. The coastal plain widens north of Bushehr on the eastern shore of the gulf and passes into the broad deltaic plain of the Tigris, Euphrates and Karun rivers. It is noticeably asymmetrical in profile, with the deepest water occurring along the Iranian coast and a broad shallow area, which is usually less than 120 feet deep, along the Arabian coast.
There are some ephemeral streams on the Iranian coast south of Bushehr, but virtually no fresh water flows into the gulf on its south-west side. Large quantities of fine dust are, however, blown into the sea by predominant north-west winds from the desert areas of the surrounding lands. The deeper parts of the Persian Gulf adjacent to the Iranian coast and the are around the Tigris-Euphrates Delta are mainly floored with grey-green muds rich in calcium carbonate.
The Persian Gulf has a notoriously bad climate. Temperatures are high, though winters may be quite cool at the north-western extremities. The sparse rainfall occurs mainly as sharp down pours between November and April and is heavier in the north-east. Humidity is high. The little cloud cover is more prevalent in winter than in summer. Thunderstorms and fog are rare, but dust storms and haze occur frequently in summer.
Until the discovery of oil in Iran in 1908, the Persian Gulf area was important mainly for fishing, pearling, the building of dhows, sailcloth making, camel breeding, reed mat making, date cultivating, and the production of other minor products, such as red ochre from the islands in the south. Today these traditional industries have declined, and the economy of the region is dominated by the production of oil.
The Persian Gulf and the surrounding countries produce approximately 31 per cent of the world's total oil production and have 63 per cent of the world's proven reserves. The Persian Gulf area will probably remain and important source of world oil for a long period.
Dams. Dams have always played an important role in harnessing Iran's precious water reserves. The Amir Kabir dam on the Karaj river is a multi-purpose dam that supplies Tehran with hydroelectric power and much needed water. With its sailing and water-skiing facilities, the dam is a popular weekend summer resort. Among others, the Manjil dam on the Sefidrood, the Mahabad dam on the Mahabad river (which supplies water for irrigation of 2,000 hectares of land, as well as domestic water and hydroelectric power), the Martyr Abbaspur dam on the Karun, and the Dez dam on the Dez river to the north of Dezful are noteworthy.
Soil Patterns. Soil patterns vary widely. The abundant subtropical vegetation of the Caspian's coastal region is supported by rich brown forest soils. Mountain soils are shallow layers over bedrock, with a high proportion of unweathered fragments. Natural erosion moves the finer textured soils into the valleys. These alluvial deposits are mostly chalky, and many are used for pottery.
The semi-aired plateaus lying above 3,000 feet are covered by brown or chestnut-coloured soil that supports grassy vegetation. The soil is slightly alkaline and contains three to four per cent of organic material. The saline and alkaline soils in the arid regions are light coloured and infertile. The sand dunes are composed of loose quartz and fragments of other minerals. Except where protect by vegetation, they are in almost constant motion, driven by high winds.
Iran has a complex climate, ranging from subtropical to subpolar. In winter, a high-pressure belt, centered in Siberia, slashes west and south to the interior of the Iranian Plateau, while low pressure systems develop over the warm waters of the Caspian, the Persian Gulf, and the Mediterranean. In summer, one of the lowest pressure centres in the world prevails in the south.
Low pressure patterns in Pakistan generate two regular wind patterns: the Shamal, which blows from February to October north-westerly through the Tigris-Euphrates Valley, and the 120-day summer wind, which sometimes reaches velocities of 70 miles per hour in the Seestan region near the Pakistan frontier. Warm Arabian winds bring heavy moisture from the Persian Gulf. The gulf area, where the heat and humidity are unbearable, stands in sharp contrast to the Caspian coastal region, where moist air from the sea mingles with the dry air currants from the Alborz to create a soft nightly breeze.
In the summer, temperatures vary from a high of 123 F (50o C) in Khuzistan at the head of the Persian Gulf to a low of 35 F (1o C) in Azerbaijan in the north-west. Precipitation also varies greatly, ranging from less than two inches in the south-east to about 78 in the Caspian region.
The annual average is about 14 inches. Winter is normally the rainy season for the whole country. Frequent spring thunderstorms occur, especially in the mountains, where destructive hailstones also fall. The coastal region presents a sharp contrast to the rest of the country.
The high Alborz mountains, which seal off the narrow Caspian Plain, wring moisture from the clouds, trap humidity from the air, and crete a fertile densely populated semitropical region with think forests, swamps, and rice paddies. Temperatures may soar to 100 F (39o C), the humidity to 98 per cent. Frost is rare.
In Iran, the change from one season to the next is fairly abrupt. By 21 March, the beginning of the Iranian year (Nowruz), the fruit trees are in full bud and fresh green wheat covers the fields. Later, while the orchards are in bloom, wild flowers carpet the stony hills. Later, the summer heat burns and kills the flowers, and autumn is not marked by a display of bright colours and the soft haze of Indian summer; instead, there is a rapid transition from summer to winter.
Settlement. There are three communities: rural, urban and nomadic.
Plain villages follow an ancient rectangular pattern. High mud walls with towers from the outer face of the houses, which have flat roofs of mud and straw supported by wooden rafters. In the open centre of the village is an occasional mosque, sometimes serving as a school, too.
The cattle that used to be herded there are now usually kept outside. Mountain villages are situated on the rocky slopes above the valley floor, they are surrounded by terraced fields, usually irrigated, of grain and lucerne (alfalfa). The houses are square, mud-brick, windowless buildings with flat or domed roofs. The stable is usually under the house.
Caspian villages are completely different. Here, where there is an abundance of water, the scattered hamlets have two-story wooden houses, frequently built on pilings, with a gallery around the upper floor. Separate out-buildings (barns, hen-houses, silk worm houses) surround an open courtyard.
Urban settlement has a long precedent in Iran. At present, around 50 per cent of the population lives in the big and medium-size cities. The biggest city of all is the capital, Tehran. Other big cities are Mashad, Shiraz, Rasht, Isfahan, Tabriz, followed by the medium-size cities like Ahvaz, Saari, Kermanshah, Hamedan, Kerman, Yazd and others. Traditional architecture and town planning have undergone notable changes in the last few decades. The European designs have largely replaced the old ones. Nevertheless, old buildings are still around in the medium-size cities, but fewer can be found in the big ones.