Yemen, Republic of, country in southwestern Asia, on the southwestern corner of the Arabian Peninsula. It is bounded on the west by the Red Sea and on the south by the Gulf of Aden (an arm of the Arabian Sea, which is part of the Indian Ocean), and is separated from Africa by the narrow strait of Bab el Mandeb. To the north and northeast lies Saudi Arabia and to the east is Oman; these two countries are Yemen's only contiguous neighbors. Yemen includes several sizable islands, most notably Socotra in the Indian Ocean, Perim in the Bab el Mandeb, and Kamaran in the Red Sea. Yemen covers about 527,970 sq km (about 203,850 sq mi). Sana'a (Sanaa) is Yemen's capital and largest city.
The Republic of Yemen was created in 1990 out of the peaceful unification of the Yemen Arab Republic (YAR) and the People's Democratic Republic of Yemen (PDRY). The YAR was commonly called North Yemen, and the PDRY was generally referred to as South Yemen, although South Yemen was actually less to the south than to the east and southeast of North Yemen. In May 1994, civil war broke out between the ruling powers of northern and southern Yemen, which had maintained separate armies and security forces as well as political differences. The fighting, which lasted more than two months and produced thousands of casualties and major economic and infrastructural damage, resulted in the defeat of southern secessionists and the survival of unified Yemen.
Prosperous and famed in ancient times, historic Yemen has been a very
poor and unknown land for more than the last thousand years. The discovery
of oil in both Yemens in the mid-1980s held out the prospect of economic
development and an easier life for the people of Yemen.
II. Land and Resources
Geologically, much of Yemen constitutes the upturned corner of the rectangular plate that defines the Arabian Peninsula. The edge of this corner takes the form of a steep, jagged mountain range that traces the western and southern limits of a high plateau; the plateau descends gradually north and east from the mountains into the desert interior, on the edge of the vast Rub' al Khali (Empty Quarter) of Saudi Arabia. To the west, the mountains drop abruptly to a low, flat coastal desert plain called the Tihamah; averaging about 50 km (about 30 mi) in width, this plain parallels the Red Sea the length of northern Yemen, turns abruptly east near the old border between the two Yemens, and then runs parallel to the Gulf of Aden for part of the length of southern Yemen. Averaging about 1,830 m (about 6,000 ft) and rising at Jabal an Nabi Shu'ayb to 3,760 m (12,336 ft), the highest peak on the peninsula, the Yemeni highlands have a generally semiarid but otherwise temperate climate, despite their location well south of the tropic of Cancer. By contrast, the coastal desert is hot and humid much of the year, and at times extremely so; summer and winter winds often bring severe sandstorms. Average temperatures for Yemen as a whole vary from about 27°C (80°F) in June to about 14°C (57°F) in January.
Every year during the summer months, monsoon winds blow inland over the water, picking up moisture, and the mountains force the warm air to rise, cool, and condense. The considerable, although erratic, seasonal rainfall allows for intensive cultivation, much of it on stonewalled terraces and in wadis—streambeds that flow with water only during and after the rains. The average rainfall in the highlands varies from 303 to 762 mm (8 to 30 in), whereas on the coast it varies from 76 to 229 mm (3 to 9 in).
The mountains of northern Yemen are cut at right angles in several places
by great wadis that feed large aquifers (underground layers of earth or
stone that hold water) at their base on the Tihamah. Moreover, since the
highlands in the north are loftier and more extensive than in the south,
the north has a generally less forbidding climate, greater rainfall, more
intensive and extensive agriculture, and a much larger population. The
eastern two-thirds of southern Yemen are basically uninhabitable, except
for coastal oases, fishing villages, the port of Al Mukalla, and the large,
well-populated district of Hadhramaut, which extends from the coast into
the country's interior.