The mainland territory and the islands of Zanzibar and Pemba make up the United Republic of Tanzania. It is situated in East Africa, immediately south of the Equator, and has a total area of 925 200 square kilometres. Although Tanzania lies in the tropics, the altitude affects its climate. Rainfall in most of the country is irregular, varying greatly in both amount and distribution over the year. Large areas have rather poor soil with a low nutrient status. Fertile soils are limited to volcanic areas in the northern highlands and the river valleys. (Finnida 1995, World Atlas 1999.)
Tanzania’s population was 29.9 million in 1997, and was growing at a rate of 2.8%. (World Atlas 1999.) Over half of the people (57%) are aged 0-19 years, and 43% of this group are adolescents (10 to 19 years old). The majority (75%) of Tanzanians live in rural areas. The low level of industrialisation explains the low rate of urbanisation. The largest part of the population are Bantu, whose migration along the river Congo took place before AD 1000. The term ‘Bantu’ refers to various tribes or groups of people speaking Bantu languages; more than 90% of Tanzanians speak Bantu languages. The Bantu in Tanzania consist of some 120 different tribes, which are identified by common names and have different languages and more or less exclusive territories. People in each tribe possess the heritage of a common culture, such as historical traditions, laws, customs, values and beliefs. Most of the groups are small: the largest, Sukuma, account for 12.4% of the total population. Benas and Hehes, who live in the southern highlands, together make up 7% of the total population. There are a remarkable number of people of Asian origin, dominating the trade sector. The official languages of Tanzania are Swahili and English, the latter still important in trade, commerce and higher learning. (Morgan 1972, Groliers Electronic Encyclopedia 1991, Finnida 1995, Ministry of Health 1996, World Atlas 1999.)