INFLUENCE OF THE RAINY SEASON ON THE PHYSICO-CHEMICAL QUALITY OF THE WATERS OF GUIDIMOUNI (EASTERN NIGER)

In the eastern part of Niger, which is arid to semi-arid, market gardening production systems are based on temporary, semi-permanent to permanent basins or ponds and lakes. In Guidimouni, in the Damagaram, the market gardening production system is associated with two permanent lakes, located side by side. The objective of the present study was to analyse the seasonal physico-chemical variations and the aptitudes for using the waters of the Guidimouni lakes. Three water sampling campaigns were carried out. The chemical analyses of the samples thus taken were carried out in the laboratory. The physico-chemical quality (Conductivity, salinity, total hardness, complete alkalometric title, Na+, K+ content) of the lake waters vary according to the dry or rainy seasons. The well waters are suitable for consumption and irrigation, the waters of KoginKarfasa range from poor suitability for consumption in the dry season to excellent at the end of the rainy season. The waters of KoginKanwa are unfit for consumption and irrigation due to high Na+ and K+ contents during the dry and rainy seasons.The salinity of K.Kans waters does not come from the surface but from the depths of the soil with a discontinuous character.