Multi-temporal Landsat-derived NDVI for vegetation cover degradation for the period 1984-2018 in part of the Arganeraie Biosphere Reserve (Morocco)

Biosphere Reserves (BRs) are especial zones established to conserve the biodiversity (ecosystem, species or genetic). Therefore, evaluating and analyzing the ecosystem degradation in these zones are crucial for protecting them. This study attempts to assess and analyze the vegetation cover degradation during the last three decades (period between 1984 and 2018) in part of the Arganeraie Biosphere Reserve (ABR) of Morocco. The study aims to describe the ecosystem degradation scenario by using multi-temporal Landsat-derived NDVI (Normalized Difference Vegetation Index), and to highlight the reasonable factors causing its degradation. Long-term and short-term NDVI changes were investigated using image difference change detection technique and IsoData classification. The obtained results confirm that about 3644.64 ha of the vegetation cover was degraded during last decade. Field investigations confirm that the anthropogenic activities caused vegetation cover degradation that last a long time (2007–2018) as confirmed by long-term analysis. Forest fire, due to charcoal production, caused degradation of about 2989.59 ha of the vegetation cover during the period 2010–2018. This study has highlighted the importance to use long-term NDVI change detection to map anthropogenic-induced vegetation cover degradation and to use short-term NDVI change detection for best chronological analysis of ecosystem degradation. In addition, the easiest proposed method offers a user-friendly tool to monitor ecosystem degradation. •NDVI-based unsupervised change detection proposed as new method to survey vegetation cover degradation in part of ABR.•Weather impact was assessed based on punctual NDVI evolution and NDVI general statistics.•Anthropogenic activities caused degradation of 3644.64 ha of the vegetation cover in the study area during last decade.•Punctual analysis of the NDVI in the burned vegetation cover highlights weather impact.•Monitoring anthropogenic activities is necessary to preserve the ABR ecosystem.