Soil erosion assessment by a GIS approach for a wide area of Northwestern Morocco

Morocco constitutes one of the Mediterranean regions where the erosion has reached its paroxysm. This ecological phenomenon is more relevant in the Rif Chain, to which belongs our study area: the Laou river watershed. This part of the Rif is generally characterized by friable formations and systematically exposed to torrential precipitations; moreover, its plant cover has known a substantial degradation during these last decades. The methodology consists to integrate the descriptive data about specific components of the natural habitat into a GIS platform, in order to survey the potential sensitivity of soils to water erosion. This may be achieved from intersecting information layers on soils, land use and topography. Cumulating the effect of these factors, we may assign a spatially distributed qualitative map of potential sensitivity, within one of 5 grades: very weak, weak, average, elevated and very elevated. The map-rendering show that severe erosion affects the Southern and Northern west sectors of the basin, even if they present the least erodible lands of all the basin and have, as well, a relatively dense plant cover. It may be concluded that both high gradient and damaged terrain state represent the main factors of water erosion in the Laou watershed

Assessment of metal pollution in the river of Martil emerging in the western Moroccan Mediterranean. Mobility and impact of human activities

This study is part of a monitoring of the evolution of variations in time and space contents of metallic elements of surface waters of the river of Martil between two sampling campaigns (May 2010 and May 2011). The comparison of the results of metal analyzes of the two campaigns show different variations of the contents of metallic elements. The magnesium content increased almost 10 times, which highlights the intensity of activities that caused this increase for one year only. The concentrations of nickel and lead fell below standards and indicate a water medium to high quality, as the concentrations of aluminum, zinc and copper, which have been reduced compared to the 2010 campaign and are still very low and do not pose a threat so large. The concentration of cadmium also decreased slightly but remains high above the standard set which is 5 mg / l, which raises some concern about this element and its possible sources. For iron, its concentration was doubled, which is why it is a beginning of water contamination because the recorded values are between 1 and 2, indicating an average water quality

Assessment of metal pollution in the river of Martil emerging in the western Moroccan Mediterranean. Mobility and impact of human activities

This study is part of a monitoring of the evolution of variations in time and space contents of metallic elements of surface waters of the river of Martil between two sampling campaigns (May 2010 and May 2011). The comparison of the results of metal analyzes of the two campaigns show different variations of the contents of metallic elements. The magnesium content increased almost 10 times, which highlights the intensity of activities that caused this increase for one year only. The concentrations of nickel and lead fell below standards and indicate a water medium to high quality, as the concentrations of aluminum, zinc and copper, which have been reduced compared to the 2010 campaign and are still very low and do not pose a threat so large. The concentration of cadmium also decreased slightly but remains high above the standard set which is 5 mg / l, which raises some concern about this element and its possible sources. For iron, its concentration was doubled, which is why it is a beginning of water contamination because the recorded values are between 1 and 2, indicating an average water quality