STATE OF AMBIENT AIR QUALITY IN MARRAKECH CITY (MOROCCO) OVER THE PERIOD 2009 – 2012

Abstract

The strong urbanization and the socio-economic development of a city cause serious effects on its environment and its population; our study focuses on the air quality of Marrakech city in Morocco, it’s the first integral study done for that city. We will give a synthesis of air pollutants measurement results; conducted in the city over the period 2009-2012; in order to determine the spatial and temporal variations of major pollutants (NOx; SO2; O3; PM10) measured at the air quality monitoring stations; as well as the weather parameters which are essential to understand the dispersion of this pollution. The results showed that the NOx levels are depending on the local emissions density and the nature of the road network. The concentrations of SO2 are low compared to the admitted Emission Limit values (ELV); this is owing to the weak industrial activity of the city and the use of less polluting fuel (350 ppm diesel).As of particles (PM10); related to road traffic; industry and natural sources; their levels exceed the thresholds limits over all sites. The city is also subject to photochemical pollution mainly due to its geographical location (strong sunlight). During the spring and the summer; the concentrations of O3 reaches an alarming levels with significant overshoot periods of the permitted limits. This study allows us to establish a first approach on the state of the air quality of Marrakech without assessing the contribution of each source; which requires a further study to identify the phenomenon.