Landsat archive for detection of change in Mediterranean ecosystems: The case of Northern Morocco

The study of changes in land cover provides a better understanding of the interactions between humans and natural ecosystems. In this context, the present study focused on the dynamics of natural ecosystems in the Rif region of Northern Morocco. The methodology was based on the inspection and visual interpretation of Landsat and Google Earth image captures, the time series of five Landsat 4-8 image bands, and the Tasseled Cap indices for a random sample of 500 points from 1984 to 2022. The study found that changes affected practically the whole study region over the study period, with around a third of them being ignored due to their very tiny magnitudes or being false positives. The findings demonstrated a general declining trend in the measured changes, indicating a reduction in pressure on different ecosystems. Furthermore, this tendency may be due in part to the availability of Google Earth images during the 2000s, which has significantly reduced the number of false positives. In terms of the year of first change, only 5.7% of pixels experienced their first events after the year 2000, implying that these pixels underwent no change for at least the first 16 years of the study period. On the other hand, 2.5% of the pixels had their last events during the first ten years and have thus remained unmodified for at least 27 years. For the year 2020, the confidence rating of the visual land cover categorization is medium to high for 88.9% of pixels using high-resolution Google Earth photos, whereas the classification quality was inadequate for 64% of pixels in 1984. Despite the stresses on the ecosystems structured by shrubs/shrubs, forests, and herbaceous/shrubs caused by the different disturbances identified, the majority of these ecosystems have not been converted to new land cover classes. According to the study, agriculture is the primary driving force underlying the conversion of forests, herbaceous/shrublands, and even shrublands/shrublands. The area increases for the latter three ecosystems represent, on the one hand, their ability to regenerate themselves and, on the other, Morocco's restoration efforts

Assessing the Impacts of Different Initiatives on the Rehabilitation of Pastoral and Silvopastoral Ecosystems: Big Data Oriented Approach

Moroccan forests, through the provision of goods and ecosystem services, underpins benefits to local communities and play a crucial role for rural area development. The legal framework recognizes to people, living near public forests, the right to graze their domestic livestock. Over the years, the grazing pressure is at levels far beyond the forestland’s carrying capacity throughout the country. Such pressure has been demonstrated as the main cause of forest cover loss and land degradation in Morocco and still threatening the sustainability of forests. To reduce the heavy grazing pressure on forest ecosystems and ensure their regeneration, several initiatives have been conducted such as the program of compensation for forest areas closed to grazing (CFCG), initiated by Moroccan forestry department. Socio-economic impact assessment of this mechanism was presented within several studies but its effectiveness for forest rangeland rehabilitation remains scarce and very spatially limited. To deal with this concern and to assess vegetation dynamics through various spatial and temporal scales, parcels concerned by CFCG and others within similar conditions was chosen. Time series of remotely sensed spectral indices at each parcel was used for vegetation cover dynamics assessment. Google Earth Engine platform (GEE) was used as computing plateform. As result, the spectral indices trends shown a long-lasting degradation tendency in areas planted without compensation compared to those concerned by CFCG. Such results were also verified using aerial images covering the analyzed parcels. As conclusion, within comparable conditions, CFCG improved vegetation cover trends. The use of GEE Platform simplified the process of treatment of remote sensed imagery and made it easy to assess the state of the vegetation and will be of great use in assessing the impacts of different programs and initiatives on the restoration of pastoral and silvopastoral ecosystems

Cloud Computing Solution for Monitoring Arid Rangeland Dynamics: Case of Moroccan Highlands and Southern Acacia Ecosystems

The wide availability of free satellite imagery, the recent development of cloud platforms dedicated to big spatial data (Big Data) that integrates both image archives from different providers, processing algorithms, distributed processing capabilities as well as an application programming interface (API) that facilitate scripting and automation process opened new perspectives for the use of vegetation observation time series over long timestamps and over large spatial scales (almost planetary). This work aims at harnessing these technologies and building up an automated solution to monitor rangeland rehabilitation dynamics in arid lands and to assess the effectiveness of stakeholder’s management strategies. Such solution is based on graphical user interface that facilitate the process and on the use of analysis functions relaying on analysing temporal trajectories (time series) of different spectral indices derived from satellite images (Landsat or Sentinel) at the required spatial analysis scale. The solution is implemented using java script as scripting language using the functions offered by GEE API. The graphical user interface of the first prototype is exploitable by the means of a standard web browser and it is accessible even to people without any background in regard to programming languages or to remote sensing skills. The process was tested for two arid sites on Morocco: acacia ecosystems on the southern part of Morocco and the highlands on Moroccan eastern parts mainly on sites recently rehabilitated. It has been qualified is promising solution

Répartition des incendies de forêts en fonction des facteurs physiques et biophysiques dans la Région du Rif (Maroc)

L’évolution actuelle du régime des incendies de forêts pose de nouveaux défis quant aux pratiques habituelles des plans d’aménagement et stratégies de gestion de ce fléau. La mise en œuvre d’actions de prévention et de lutte nécessite une compréhension fine de l’occurrence et de propagation des feux. Le présent travail vise en une analyse spatio-temporelle des feux de forêt en fonction des facteurs physiques et biophysiques dans la région du Rif au Maroc, considérée comme une des régions les plus touchées par ce fléau à l’échelle nationale. Les incendies survenus dans cette région, entre 1997 et 2011, ont été analysés et classés en trois groupes de sévérité selon l’ampleur des superficies touchées. Cette analyse a montré que presque 80% des superficies incendiées ont été enregistrées durant les mois d’août et septembre. Par la suite, l’utilisation d’une analyse de variance déséquilibrée à deux facteurs a permis de montrer la présence d’une différence significative entre la sévérité de l’année et les types de bioclimat, notamment pour les bioclimats à hiver chaud caractérisés par une production abondante de biomasse. Aussi, l’étude révèle que pendant les années sévères, la végétation des hautes altitudes devient plus vulnérable aux feux, particulièrement pour les altitudes dépassant 2000 m, en revanche, l’effet de la pente et de la continentalité n’est pas significatif et ne présente aucune influence sur l’occurrence des feux