Comparison of Two Methods for Groundwater Pollution Intrinsic Vulnerability Mapping in Wadi Nil (Jijel, North-East Algeria)

The excessive use of fertilizers in agriculture led to the increase of the nitrates pollution of wadi Nil groundwater (Jijel, North-East Algeria). The use of fertilizers in high quantities with respect to the plants’ needs will lead to the leaching and infiltration of the excess fertilizers towards groundwater by increasing the nitrate percentage, which ultimately leads the contaminant’s level to exceed the allowed norms of water consumption (50 mg/l). The aims of this work were to assess the aquifer’s vulnerability caused by pollution using DRASTIC and GOD methods. The study is based on the obtained measurements during the field surveys conducted during the hydrological year 2010–2011 and supplemented by the compilation of the information collected from various technical services of Jijel city. The comparison of nitrate-concentration distribution map and that of vulnerability levels obtained by each approach, showed that the DRASTIC method was the most appropriate in this case with a percentage of 71.4% versus 47.2% for GOD method. It was found that the studied water was characterized by a medium to high degree of vulnerability, which requires finding solutions to protect and preserve the water of this area.