西アフリカ・サヘル地域の地下水

とくにセネガル.マリ・ニジェールについて

抄録

This paper describes a brief outline of ground-water resources in Senegal, Mali and Niger, of the Sahel of West Africa.
In Senegal, the principal aquifers are the sand stone of Continental terminal in the central part, the dune sand on the coast of the Atlantic, Alluvial deposits along the River Senegal, the River Ganbia and others, and Paleozoic and Precambrian rocks in the South East. Yields of wells are generally lower in most rocks and higher in Continental terminal. Most of ground water is potable in the chemical quality, but is contaminated locally by sea water along the rivers.
In the eastern part of Mali, the principal aquifers are Alluvial deposits along the River Niger and wadies, the sand stone of Continental terminal and Continental intercalaire. The water-yielding properties of Alluvium are generally better than the others. The chemical quality of water is better in shallower aquifer than the deeper. Most of wells are“ puits”, about two meters in diameter, and utilized for drinking and livestock.
In the Air region of Niger, the principal artesian aquifers are the sand stone of Cretaceous and Carboniferous. Most of wells are under flowing condition, and yield generally mineralized water, rich in sodium bicarbonate and/or sodium sulfate.