FINE RESOLUTION IMAGERY AND GIS FOR INVESTIGATING THE MORPHOLOGICAL CHARACTERISTICS, AND MIGRATION RATE OF BARCHAN DUNES IN THE ERG SIDI MOUSSA DUNEFIELD NEAR IN-SALAH (ALGERIA)

This research interested in determining the morphological characteristics and barchan movement, within the Erg Sidi Moussa dunefield near In-Salah (central Algerian Sahara). Based on field measurements, 12 individual barchan dunes have been subjected to morphological investigation, results showed that normal variety is more prominent compared to slim, pudgy and fat forms, according to the classification of Bourke and Goudie (2009). Based on fine resolution imagery and GIS, the rate and trend of barchan dune migration has been accurately measured. From Jan. 5, 2013 to Feb. 3, 2016, the average of movement rate was estimated to be 14 mlyr and movement angle to be about 64, in well accordance with the prevailing wind direction and the sand transport trend. Results revealed as well that the barchan dune movement is inversely proportional to the dune dimensions, meaning that dunes of smallest height and width are moving much faster than more-sized ones. Due to its position downwind, In-Salah city is facing a real risk of accumulating sand and mobile dunes. To mitigate damages, it is highly recommended that dune fixation techniques be realized upwind, and that the risk management be considered for future planning projects.