Tazizat is small, only about 4,000 square kilometres or around 60x60 kilometres, or smaller in area than Northern Ireland. The total population is only around 300,000, about 100,000 of whom live in the capital, Ragaj, with the rest living in subsistence farming communities along the banks of the Senegal river or around reliable water sources in the desert. The terrain is very flat, averaging around 40 metres above sea level despite the inland location. Soils are eroded due to the moderate rainfall but are replenished by windborne particles from the Sahara, bringing iron and moderating pH.
Because annual rainfall is low, only around 300-400mm, and evaporation is very high due to the extreme heat of the Sahel, agriculture is limited in most areas. Historically, herders grazed livestock at oases and moved as the water was depleted, returning in future once it had been replenished. Crops were only cultivated at the banks of the Senegal river, which flows from the rainier tropical savannah and forest to the south. Almost all of the rain falls in summer, lasting from late June to early September, and outside of these months water is very scarce. In most years, no rain falls from November to March. Hence, the government has embarked on a number of dam-building projects.