This thesis was carried out on the framework of the programme OPUR (Observatory of Urban Pollutants). The main objectives were to improve the current knowledge on generation and transfer mechanisms of aliphatic and polycyclic aromatic hydrocarbons on different spatial scales within the Parisian combined sewer. The first section is focused on the pollutant entry pathways in the combined sewer during dry and wet weather periods. The second one aimed to better evaluate the spatial evolution of the hydrocarbon pollution within different urban catchments, which area cover from 42 to 2 581 ha. Results revealed for the considered catchments, that the characteristic and transfer of hydrocarbons do not evolve in relation to the spatial scale.Ce doct...