Algeria, with a surface of 2,4 millions km², is the largest country of northern Africa. Most of its surface is covered by the Sahara, inappropriate for agriculture, but rich with mineral resources.
More than 90 % of the population lives in the North of the country where a coastal band stretches along the Mediterranean Sea, with plains, mountains, and high lands. In the North, the annual amount of rain varies between 300 and 1000 mm, whereas in the Sahara and southwards the Saharian Atlas, it is below 100 mm.
Algeria has 17 major hydrographical basins, sharing with Tunisia the Medjerda basin and with Morocco the Tafna, Draa, Guir and Daoura basins.
In terms of general administration, the country is divided into 48 wilayas (departments), 567 dairates (under-departments) and 1540 municipalities.
According to the 1998 census, and up to the 25th March 1998, Algeria’s population was of 29 million inhabitants. The previous census (1987) put the population at 23 million inhabitants which represents an annual increase of 2.28 %. To the end of 2005, the total population was estimated to 32 million inhabitants.
The rate of the urban population (major and secondary agglomerations) has constantly increased from 56,1 % in 1966 to 61,2 % in 1977, 70.8 % in 1987 and 80.8 % in 1998. Five wilayas (Algiers, Setif, Oran, Tizi Ouzou and Batna) group together more than the quarter of the population. Apart from Algiers, there is relatively an important concentration of the population in Northern cities of the country which exceeds 50.000 inhabitants.According to the 1998 census, 70,78 % of the households are connected to a drinking water network, and 66,34 % to a sewage network. It is interesting to notice that the number of inhabitants per house has moved from 7,54 in 1987 to 7,14 in 1998 and it is for the first time, since the Independence that this ratio has been reduced.
About 65 % of the water consumption from the total water is used by agriculture, especially because the new agricultural techniques are not yet frequently used.