Geography of Asia
Western Asia, West Asia, Southwest Asia or Southwestern Asia are terms that describe the westernmost portion of Asia. The terms are partly coterminous with the Middle East – which describes geographical position in relation to Western Europe rather than location within Asia. Due to this perceived Eurocentrism, international organizations such as the United Nations, have replaced Middle East and Near East with Western Asia. This region and Europe are collectively referred to as Western Eurasia.
See also: Geography of Asia
Western Asia is primarily arid and semi-arid, and can be subject to drought; nonetheless, there exists vast expanses of forests and fertile valleys. The region consists of grasslands, rangelands, deserts, and mountains. Water shortages are a problem in many parts of West Asia, with rapidly growing populations increasing demands for water, while salinization and pollution threaten water supplies. Major rivers, including the Tigris and Euphrates, provide sources for irrigation water to support agriculture.
There are two wind phenomena in Western Asia: the sharqi and the shamal. The sharqi (or sharki) is a wind that comes from the south and southeast. It is seasonal, lasting from April to early June, and comes again between late September and November. The winds are dry and dusty, with occasional gusts up to 80 kilometers per hour (50 miles per hour) and often kick up violent sand and dust storms that can carry sand a few thousand meters high, and can close down airports for short periods of time. These winds can last for a full day at the beginning and end of the season, and for several days during the middle of the season. The shamal is a summer northwesterly wind blowing over Iraq and the Persian Gulf states (including Saudi Arabia and Kuwait), often strong during the day, but decreasing at night. This weather effect occurs anywhere from once to several times a year.
While Western Asia mainly contains areas with low relief, Turkey, Iran, and Yemen include mountainous terrain. The Anatolian Plateau is sandwiched between the Pontus Mountains and Taurus Mountains in Turkey. Mount Ararat in Turkey rises to 5,165 meters. The Zagros Mountains are located in Iran, in areas along its border with Iraq. The Central Plateau of Iran is divided into two drainage basins. The northern basin is Dasht-e Kavir (Great Salt Desert), and Dasht-e-Lut is the southern basin.
In Yemen, elevations exceed 3,700 meters in many areas, and highland areas extend north along the Red Sea coast and north into Lebanon. A fault-zone also exists along the Red Sea, with continental rifting creating trough-like topography with areas located well-below sea level. The Dead Sea, located on the border between the West Bank, Israel, and Jordan, is situated at 418 m (1371 ft) below sea level, making it the lowest point on the surface of the Earth.
A large lowland belt is located on the Arabian Peninsula, from central Iraq, through Saudi Arabia, and to Oman and the Arabian Sea. The Euphrates and Tigris rivers cut through the lowland belt in Iraq and flow into the Persian Gulf. Rub’ al Khali, one of the world’s largest sand deserts, spans the southern third of the Arabian Peninsula in Saudi Arabia, parts of Oman, the United Arab Emirates and Yemen. Jebel al Akhdar is a small range of mountains located in northeastern Oman, bordering the Gulf of Oman.
Three major tectonic plates converge on Western Asia, including the African, Eurasian, and Arabian plates. The boundaries between the tectonic plates make up the Azores-Gibraltar Ridge, extending across North Africa, the Red Sea, and into Iran. The Arabian Plate is moving northward into the Anatolian plate (Turkey) at the East Anatolian Fault, and the boundary between the Aegean and Anatolian plate in eastern Turkey is also seismically active.
Several major aquifers provide water to large portions of Western Asia. In Saudi Arabia, two large aquifers of Palaeozoic and Triassic origins are located beneath the Jabal Tuwayq mountains and areas west to the Red Sea. Cretaceous and Eocene-origin aquifers are located beneath large portions of central and eastern Saudi Arabia, including Wasia and Biyadh which contain amounts of both fresh water and saline water. Flood or furrow irrigation, as well as sprinkler methods, are extensively used for irrigation, covering nearly 90,000 km² across Western Asia for agriculture.