Application of Principal Component Analysis to the study of nitrate pollution of groundwater of the littoral zone Sidi Abed-Ouled Ghanem (Province of El Jadida, Morocco)

In this work, we will study the nitrate pollution level in the groundwater of the coastal area between Sidi Abed and Ouled Ghanem (Province of El Jadida, Morocco). This area is characterized by the dominance of vegetable market gardening and cattle breeding. The aim of this study is to identify the main factors contributing in nitrate pollution. It was based on piezo-metric data, Lambert coordinate and the results of physicochemical analyzes of the water from 73 wells. The principal components analysis (PCA) was applied to all data collected. Firstly, the descriptive statistics shows that the well depth varies between 1 and 75 m with 16.5 m as average. Nitrate levels vary between 25.7 mg/l and 161.5 mg/l with 89 mg/l as average. Secondly, the results of the PCA revealed the impact of the depth, correlated with the geographic location, on the quality of 89% of the wells. However, 11% of the wells remain indifferent to this parameter. In this case, we can say that nitrate pollution is mainly due to the geological nature of the region allowing greater infiltration of nitrates.