Yemen - Geography

Geography

Yemen is located in Western Asia, in the southern half of the Arabian Peninsula, bordering the Arabian Sea, Gulf of Aden, and the Red Sea. It lies south of Saudi Arabia and west of Oman, between latitudes 12° and 19° N and longitudes 42° and 55° E.

A number of Red Sea islands, including the Hanish Islands, Kamaran, and Perim, as well as Socotra in the Arabian Sea, belong to Yemen. Many of the islands are volcanic; for example Jabal al-Tair had a volcanic eruption in 2007 and before that in 1883.

At 527,970 km2 (203,850 sq mi), Yemen is the world's 50th-largest country. It is comparable in size to Thailand and larger than the U.S. state of California. Yemen is situated at 15°N 48°E / 15°N 48°E / 15; 48.

Until the signing of the Yemen-Saudi Arabia peace treaty in July 2000 Yemen's northern border was undefined; the Arabian Desert prevented any human habitation there.

The country can be divided geographically into four main regions: the coastal plains in the west, the western highlands, the eastern highlands, and the Rub al Khali in the east.

The Tihamah ("hot lands" or "hot earth") form a very arid and flat coastal plain along Yemen's entire Red Sea coastline. Despite the aridity, the presence of many lagoons makes this region very marshy and a suitable breeding ground for malaria mosquitoes. There are extensive crescent-shaped sand dunes. The evaporation in the Tihamah is so great that streams from the highlands never reach the sea, but they do contribute to extensive groundwater reserves. Today, these are heavily exploited for agricultural use. Near the village of Madar about 48 km (30 mi) north of Sana'a, dinosaur footprints were found, indicating that the area was once a muddy flat.

The Tihamah ends abruptly at the escarpment of the western highlands. This area, now heavily terraced to meet the demand for food, receives the highest rainfall in Arabia, rapidly increasing from 100 mm (3.9 in) per year to about 760 mm (29.9 in) in Ta'izz and over 1,000 mm (39.4 in) in Ibb.

Agriculture here is very diverse, with such crops as sorghum dominating. Cotton and many fruit trees are also grown, with mangoes being the most valuable. Temperatures are hot in the day but fall dramatically at night. There are perennial streams in the highlands but these never reach the sea because of high evaporation in the Tihamah.

The central highlands are an extensive high plateau over 2,000 metres (6,562 ft) in elevation. This area is drier than the western highlands because of rain-shadow influences but still receives sufficient rain in wet years for extensive cropping. Diurnal temperature ranges are among the highest in the world: ranges from 30 °C (86 °F) in the day to 0 °C (32 °F) at night are normal. Water storage allows for irrigation and the growing of wheat and barley. Sana'a is located in this region. The highest point in Yemen is Jabal an Nabi Shu'ayb, at 3,666 metres (12,028 ft).

Yemen's portion of the Rub al Khali desert in the east is much lower, generally below 1,000 metres (3,281 ft), and receives almost no rain. It is populated only by Bedouin herders of camels. The growing scarcity of water is a source of increasing international concern. See Water supply and sanitation in Yemen.