Contribution of Satellite Imagery to Study Salinization Effect of Agricultural Areas at Northern Eastern Oasis Algerian Region

Abstract

This paper summarized a new and precise spatio-morphological mapping of cultivable area located at northern-eastern oasis Algerian region affected by land salinization phenomena. We gave qualitative and quantitative views by mapping the presence of salt deposit transported by watersheds, accumulated in the same region and raised to the surface following the Albien’s drainage for the irrigation of the settlements, or by tectonic movement at depth. In order to study a spacious area with a metric precision, processing optical remote sensing data were required. We processed heterogeneous data; from satellites (sentinel-2b multi-spectral) Combined with an old map of the area and field measurements to produce a new and more accurate up-to-date map. The results obtained by applying supervised classifications (Artificial Neural Network) combined with unsupervised (K-means) methods show the amount of salt on cultivable region over the areas of Touggourt. We deduced the risk that the nearest areas (not yet affected by this phenomenon) have to face. Five classes extracted from the satellite image: salt, sand, agricultural land, palm trees, and buildings Show the distribution of salinity levels as well as the cultivability trend of each class. The total salt (salinization) occupation rate of ~24%, which represents 1/4 of the area affecting almost all cultivable and palm classes.