Abstracto

Physical and chemical analysis of the nitric pollution of M’nasra groundwaters in irrigated areas

I.Idrissi Alami, A.Echchelh, A.Rhidouani, M.Zeraouli, M.Addou

The area of MÂ’nasra, which has a water table that represents the only resource, allows the supply of a population of 140 000 inhabitants. It ensures the development of a dynamic irrigation over an area of about 38 000 Ha inwhichmore than 50%of lands are sandy soils that are very permeable. This coastal zone is a place where agriculture is very intensive supported by fertilizers composed of nitrogen and pesticides that are used at a large scale. This work deals with the physical and chemical study of waters from 59 wells and the spatial and temporal evolution of the nitric pollution during the campaign periods of 1993, 2003, 2007 and 2008 for different places of MÂ’nasraÂ’s region. The results of the statistical analysis have shown a mutation of the nitric pollution in the region. This reveals that 73.6% of observed wells do not respect the World Health Organization (WHO). Furthermore, the spatial analysis has shown up a nitric pollution spread on an area of 1370 Ha between the years 1993 and 2008.