Spatiotemporal evolution in sub-humid region based on aerial photographs and satellite imagery: Case study in agni sub-catchment, Northern Morocco

Abstract

This study investigated the land use/land cover (LULC) and their evolution during the past six decades using maximum likelihood classification (MLC). The data from aerial photographs and satellite imageries are the primary sources that provide an opportunity to acquire information about LULC change. The study was based on three periods of LULC maps derived from aerial photographs 1960, 2000 and satellite imageries Landsat ETM + for 2000, Landsat 8 and Sentinel 2B for 2020 and Terra Incognita™ were used during image classification. For accuracy assessment, the confusion matrix was achieved. Since the 1960s, the LULC has changed in Agni sub-catchment (sub-basin): increase of agriculture areas with the expense of forest in the study area. The results disclosed that Agni sub-catchment has changed significantly between 1960 and 2020. The forest was reduced from 17.4% in 1960 to 13.6% in 2020, but the agriculture was expanded from 46.9% in 1960 to 56.3% in 2020. This shows that agriculture increased at the expense of forest, this is due to policy change, population pressure and integration of cannabis in farms since 2006. The socio-economic crisis in 1980s aggravated by the shortened of fallow periods and the shortage of farmland land were major driving forces of the LULC changes, forced farmers in the Agni sub-catchment to seek new resources for subsistence. This situation has led to an increase in the frequency of migration to other cities and to Europe, especially among young people. This results in a vicious circle whose modalities of functioning we aim to analyze in this study, in order to contribute to a better understanding of the sub-humid to semi-arid Mediterranean environments of the Rif region.