This book is a Ph.D thesis. The elaborated study was carried out in Moroccan city (Meknes City) and more particularly along the Oued Boufekrane River that passes inside this city. Many samples (soil, sediment and water) were collected along the study area and during two campaigns of sampling. The collected samples were analyzed using different analytical techniques mainly WD-XRF and ICP-AES. The treatment and the interpretation of the obtained results were carrying out exploiting many statistical tools. So, statistical tests were used to compare the results obtained by WD-XRF and ICP-AES; and the multivariate statistics was applied to define the emission sources in the studied area. The analyses of metal contents in soil samples showed that the distribution of these elements, along the studied sites, is homogeneous; with the exception of Pb that showed high contents at the vicinity of the road axes. In sediments, two groups have been distinguished; the first group showed enrichment downstream the city and the second group indicated enrichment inside the city. These results have been corroborated by the calculation of the correlation matrixes and a Principal Components Analysis.