Libya is part of the African survey as well as the Near East survey. The Libyan Arab Jamahiriya has a total area of about 1.76 million km2. It is bordered in the east by Egypt and Sudan, on the south by Chad and Niger, in the west by Algeria and Tunisia, and in the north by the Mediterranean Sea. The climatic conditions are influenced by the Mediterranean sea to the north and the Sahara desert to the south, resulting in an abrupt transition from one kind of weather to another.
Rain is rare and irregular and diminishes progressively towards zero.
Sixteen dams, with a total storage capacity of 387 million m3 and with an expected average annual volume of water controlled in the order of 60 million m3, had been constructed by 1991. Additional dams are planned, to achieve a total storage capacity of 686 million m3. This difference between the average annual runoff and the storage capacity of the dams is so that the runoff water of exceptionally wet years can be stored. Not all the renewable groundwater can be abstracted without affecting the environment, because of the deterioration of water quality by saline water encroachment. South of the 29th parallel, an important development of Palaeozoic and Mesozoic continental sandstone enabled water to be stored safely during the long period of the late Quaternary, before the climate turned extremely arid.