No abstract

Vegetation cover degradation is still a very common problem in many parts of Morocco; moreover, it affects straight up the amount of the annual soil loss rate. The analytical approach used in this study, respectively, includes remote sensing techniques, application of USLE (Universal Soil Loss Equation) and overlay analysis in a raster Geographic Information System (GIS) environment, employing available information on the region covering the Kalaya catchment. Thus, this procedure allowed the calculation of the NDVI (Normalized Difference Vegetation Index), the execution of two types of classification (unsupervised and supervised) for 1999 and 2010 imagery and eventually the prediction of soil erosion risk in the watershed in question. The main outcome was the production of multidate vegetation cover maps, land use maps and soil loss risk maps. The overlay of two maps allowed us to highlight the changes occurred in this area, which evidence the high anthropogenic impact on the dynamics of land use and vegetation cover. The results suggest that the outputs of this study can be used for predicting rate of soil loss, which varied from 31.68 t•ha −1 •yr −1 in 1999 to 34.74 t•ha −1 •yr −1 in 2010.

Coastal areas represent one of the country's most important environmental and economic resources. They are naturally dynamic, with changes that can occur on a human time scale and that need to be quantified for the proper management of shorelines and, in particular, the beaches on which the local economy is largely based. This work focuses on the diachronic study of the coastline of the Mediterranean coast, particularly the coastal fringe at the mouth of the Wadi Aliane. In order to assess and remedy the risks of erosion and accretion of the coastline, the methodology followed consists of the application of automatic analytical techniques using multi-temporal photo-interpretation, a Geographic Information System (GIS) and a Digital Shoreline Analysis System (DSAS). The rate of change will be calculated from the multi-date maps, (1981- 1997 and 2016) using the End Point Rate (EPR) index. Comparison of the results of the interpretation of aerial photos and satellite images of the Oued Aliane coastline used (1981, 1997, and 2016) provided information that allowed us to understand the evolutionary behaviour of the wet sand/dry sand line over 36 years. This numerical analysis of the 1981 -1997 and 2016 coastlines in the coastal sector of Oued Aliane, shows us that zones A, C and D are mainly affected by erosion, while the mouth part is affected by accretion because it is considered a delta and therefore a sedimentation area.