Diachronic analysis of the steppe land cover of the department of Sidi Bel- Abbes using the remote sensing (Western Algeria)

The land cover modes of the steppe area of the Willaya of Sidi Bel-Abbes (Western Algeria) have witnessed different mutations during the period of 1987 to 2013; compromising the future of the pastoral activity. This dissection is based on a supervised classification of TSAVI values (Transformed Soil Adjusted Vegetation Index) using images of remote sensing of medium spatial resolution of Landsat-TM 5 and 8 types. The satellites scenes were used undergoes atmospheric preprocessing. This step aims to create time series of images free of clouds and shadows. The determination of the land cover status and the validation of remote sensing maps by the confusion matrix show that the state of the halophilic/psammophitic steppes and the matorral are detected in 38.38% and 55.71% of cases, respectively. On the other hand, the chamaephytic steppes mark only -9.81% of regression, agricultural land24.51% and -46.24% of dense vegetation are correctly mapped. The medium resolution remote sensing is therefore, in the light of these statistics, a relevant and effective management tool of the steppe area, which, in addition, allows enriching the area in view of an appropriate accommodation plan for the fight against desertification.