Vol. 10, Issue 6, Part C (2024)

Abstract
This study was carried out in the commune of Simiri, Ouallam department, in the Tillabéri region. Its aim was to establish the spatio-temporal occupation of the land between 1970 and 2020. The methodology involved a diachronic study based on Landsat satellite images. The images were processed using ArcGIS 10.3 software. A total of five (5) different land use classes were selected: vegetation class, agricultural zone class, residential zone class, bare soil class and water body class. The results showed that between 1973 and 2020, vegetation had declined significantly in the municipality. Vegetation cover fell from 42% in 1973 to 10.64% in 2020. On the other hand, the surface areas of agricultural and residential zones, as well as bodies of water, have increased. Agricultural areas increased from 16.6% in 1973 to 36.75% in 2020. Residential areas increased from 10.5% in 1973 to 20.92% in 2020. The area under water rose from 2.9% in 1973 to 2.6% in 2010 and 4.5% in 2020. Bare soil increased from 27.97% in 1973 to 32.40% in 2010, then fell to 27.15% in 2020. The study found that woody formations are deteriorating, while human activities are increasing.