Introduction

Libya, a region in North Africa. Much of the country lies in the Sahara Desert, and a substantial part of its population is clustered along the coast and its immediate hinterland, where Tripoli (Saharabulus), the de facto capital, and Banghazi (Benghazi), another major city, are situated.
Libya is made up of three historical regions—Tripolitania in the northwest, Cyrenaica in the east, and Fezzan in the southwest. They were regarded by the Ottoman authorities as independent provinces. Under Italian rule, they were joined to form a new colony, which gave way to an independent Libya. Through most of Libya’s early history, Tripolitania and Cyrenaica became more closely intertwined with adjacent regions than with one another.
Before the discovery of oil in the late 1950s, Libya was considered low in natural resources and heavily bound by its desert climate. The world was almost entirely dependent on foreign assistance and imports for the maintenance of its economy; the discovery of oil drastically changed this situation. For a long time, the government maintained firm power over the economy and sought to grow agriculture and industry with resources extracted from its large oil revenues. It has developed a welfare state that offers medical care and education to people at a minimum cost.
Libya is surrounded by the Mediterranean Sea in the north, Egypt in the east, Sudan in the south-east, Niger and Chad in the south, and Tunisia and Algeria in the west.
Libya is underpinned by pre-Cambrian basement rocks (from around 4 billion to 540 million years ago) riddled with coastal and wind-borne deposits. The key physical features are the Nafūsah Plateau and the Al-Jifārah (Gefara) Plain in the northwest, the Akhār Mountains (Green Mountains) in the northeast, and the Saharan Plateau, which occupies a large part of the rest of the region.
The Al-Jifārah Plain occupies nearly 10,000 square miles (26,000 square kilometers) of the northwest corner of Libya. It rises from the sea level to around 1,000 feet (300 meters) on the foothills of the Nafūsah Plateau. Composed of sand dunes, salt marshes and steppes, the plain is home to much of Libya’s population and its largest city, Tripoli. The Nafūsah Plateau is a limestone massif that extends for approximately 212 miles (340 km) from Al-Khums on the coast to the Tunisian border at Nālūt. It rises steeply from the Al-Jifārah Plain west of Tarhūnah, reaching elevations between 1,500 and 3,200 feet (450 and 975 metres).
In Libya, there are no permanent rivers. The various wadis that drain the uplands are flooded with flash flooding during the rains, but then they dry up easily or are reduced to a trickle. The main wadi systems are Wadi Zamzam and Wadi Bayy al-Kabīr, all of which are empty into the sea on the western coast of the Gulf of Sidra. Other broad wadis drain the inner basins of Sirte, Zelten and Fezzan. However, there is still substantial underground water. Numerous oases are watered by wells and streams, and artesian wells are used by large deep fossil aquifers in Fezzan and south-eastern Libya; the Great Man-Made River was one of the more ambitious schemes to make use of these groundwater deposits. (See the map showing the phases of the Great Man-Made River project that were proposed or completed at the time of the 2011 Qaddafi Rebellion.) Along the coastline there are many salt pans, or sabkhas, created by the ponding and evaporation of water behind coastal dunes. Main salt flats are located in Tāwurghā, Zuwarah, and the Benghazi Plain.

The gray-brown soils of the Al-Jifārah Plain and the Nafūsah Plateau in the west are fertile, although over-irrigation has contributed to increased soil salinisation. In the east, the soils of the Barce plain—which range between the Akhimar Mountains and the sea—are light and rich. Rich alluvial deposits are found in the coastal deltas and valleys of the Great Wadi. On the edges of the Sahara, the soil has been badly degraded by agriculture and overgrazing. The remainder of the world is dominated by wind-ridden sand or a stony desert. The soils in these areas are underdeveloped, with no organic content.