Integrating Sentinel-2 Data and PAPCAR Model to Map Water Erosion: Case of Beni Boufrah Watershed

Water erosion causes significant economic losses linked mainly to the silting up of dams and losses in soil productivity, these consequences will increase if soil and water conservation actions associated with development actions are not undertaken. The present work aims to evaluate the water erosion in the basin of the Beni Boufrah located in the Northern part of Morocco. The hierarchy of this basin in plot according to the degrees and the tendencies of the erosion was made using the qualitative PAP/CAR approach (Programme d’Actions Prioritaires/Centre d’Activités Regionales) which is based on the integration of the factors influencing the water erosion, such as the slope, lithology and/or pedology, vegetation cover and land use. This work was conducted in three stages, the first one being predictive based on the analysis of the natural factors influencing water erosion and the processing of databases of developed maps. The second so-called descriptive stage is based on the mapping of different forms and processes of soil loss that occur in the study area. The last step, it allows the integration and the combination of the results of the two previous steps. Its purpose is to provide a precise cartographic product that reflects the reality of the state of soil degradation and the future evolution of erosion. The consolidated erosion map shows that more than half of the basin area (53%) is affected by medium-level erosion, 13% is affected by high erosion level, and 15 % is affected by low-level water erosion. Low-intensity erosion occurs along the river in areas where the slope and lithology favour runoff. The trend map is the final result of the integration phase, it describes erosion trends in the different parts of the basin and is, therefore, a tool to guide decisions on land use planning and tillage methods to limit the risk of water erosion in the basin. Keywords: Oued Beni Boufrah, water erosion, PAP/CAR, erosive states, erosion trend

Il faut sauver la forêt de la Maâmora (Maroc).

La forêt de la Maâmora (Maroc) est considérée comme la plus vaste subéraie de plaine au monde. Elle constitue un espace récréatif pour la population des grandes agglomérations urbaines (Rabat, Salé, Khémisset et Kénitra), et la principale source de revenus pour une population usagère, dont les besoins s'accroissent de plus en plus (300 000 habitants). Cet article souligne la gravité d'une évolution régressive qui se poursuit inexorablement, bien que connue de longue date par les autorités. Il fait ressortir les causes et l'état inquiétant de la dégradation de cette forêt, dont l'importance socio-économique n'est plus à démontrer. Il propose quelques remèdes en vue de son sauvetage, notamment une action vigoureuse de développement local par l'amélioration du niveau de vie des habitants usagers riverains

Spatio-temporal analysis of North African forest cover dynamics using time series of vegetation indices – case of the Maamora forest (Morocco)

North African forest areas play several roles and functions and represent a heritage of great economic and ecological importance. As a result of global changes, that act independently or synergistically, these areas are currently undergoing a pronounced degradation and their productivity is decreasing due to several factors. This work aims to characterize spatio-temporal dynamics of vegetation within the Maamora forest. This forest is considered as the most extensive cork oak woodland in the world and is divided, from west to east, into five cantons A, B, C, D and E. The data, extracted between 2000–2021 from MODIS NDVI/EVI images of 250 m, were analyzed using statistical parameters with the Pettitt homogeneity and the Mann-Kendall trend tests, with their seasonal and spatial components, in order to better consider the vegetation distribution of this forest. Results show a clear temporal and spatial (inter-canton) variability of vegetation intensity, unrelated to the continental gradient. In fact, recorded mean values in cantons C and E are significantly higher than those of cantons B and D respectively. This is confirmed by both regressive and progressive trends, which were identified respectively from the months of March 2012 and October 2008, in the data series of cantons B and E successively. Spatially, the regressive dynamic remains generalized and affects more than 26.7% of the Maamora’s total area with extreme rates (46.1% and 14.0%) recorded respectively by the two aforementioned cantons. Similarly, all the stand types in canton B show the highest regressive rates, especially the cork oak regeneration strata (75.4%) and the bare lands (86.1%), which may explain the positive tendencies identified by the related series during the fall season. However, the cantons C and E record the lowest rates, respectively, for natural stands of cork oak and artificial plantations. These results highlight also the absence of a causal relationship between the contrasting vegetation dynamics of the Maamora and the climatic conditions, expressed here by the continental gradient. However, they do highlight the effects of other factors, particularly those of a technical nature

I prodotti forestali non legnosi, un'occasione di sviluppo locale. Il caso della foresta della Maamora (Marocco).

Vengono descritti i prodotti non legnosi dalla foresta della Maamora, nel Marocco settentrionale, e discusso il rapporto fra la popolazione locale e la conservazione di qusta vasta e peculiare fitocenosi