Use of Remote Sensing and GIS to Study the Expansion of Sands and Vegetation in the Draa Region (Morocco) From Landsat Satellite Images

The Draa region, located in the southern part of Morocco, has been faced with a significant increase in desertified surfaces, sand deposits, and a decrease in vegetation cover. The region's ability to develop is hampered by this issue. Through a spatio-temporal study, this project aims to contribute to the comprehension and quantitative assessment of these potential risks. Understanding the dynamics of land use is made possible by the merging of remote sensing and geographic information systems techniques. For this diachronic analysis, two multidate satellite images are employed (Landsat 7 ETM+ 2001 and Landsat 9 OLI 2023). After all the necessary processing of these images, a map of changes is generated by the difference between the two land use maps, which correspond to the two dates of the time interval considered in the project. This allows us to make a diachronic analysis and highlight the change in each component of the studied environment. The obtained results are validated by contrast with other climatic data and by examining the correlations between the remote sensing parameters. The changes are important, especially for the vegetation cover and the migration of sands in the considered area. This is due to the influence of climatic factors. After digitization, it is evident that in comparison to 2001, there was a 43.46% decline in vegetation in 2023. By 2023, living sand will have taken over 20.90% of the area that was covered by vegetation in 2001, posing the biggest threat to the palm oasis.