DIAW Moctar^1,, MALL Ibrahima¹, SANE Seyni², MADIOUNE H.Diakher¹, FAYE Serigne¹

In arid and semi arid zone, irrigation constitutes one of determinants of agricultural production expansion. However, the irrigated agriculture development can be a threat to the environment in these areas due to multiple soils degradation that can result (salinization, sodisation and alkalinization). Most of problems come from of the irrigation water typology, land use characteristics, water resources management and farming systems or irrigation schemes. In Delta and Lower Senegal River valley, irrigated agriculture produces currently many problems related to the degradation of soils and waters quality. Indeed, the use consequences for agricultural of different water qualities, impose the need to classify them according to their suitability for irrigation. The assessment and monitoring of water quality and soil are essential to ensure a profitable and sustainable irrigated agriculture in the delta alluvial plain. Thus, in this study water sampling was carried out during two campaigns (in July 2005 and December 2013). RICHARDS and WILCOX diagrams and statistical analysis through Ascending Hierarchical Classification (AHC) were used to classify and evaluate the impact of water on soils physical and chemical characteristics. Establishing suitability maps of water for irrigation from these different approaches, made it possible to highlight the different quality of water classes (Excellent, Good, Acceptable and Bad) and their repercussions on intrinsic characteristics of the natural environment especially potential risks to degradation by salinization and alkalinization in irrigated soils.

irrigation, water suitability, repercussion, salinization, soil, delta and lower senegal river valley