Movement of sand dunes and its impact on the road of Al Uqayr- Al Hofuf in the Kingdom of Saudi Arabia using remote sensing

Sand forms cover about 50% of the total area of ​​the Kingdom of Saudi Arabia (KSA), and it is one of the most important and distinctive geomorphological features in the Kingdom. The movement of sand dunes, especially barchan dunes which represent a great danger that hinders the development processes. Al Uqayr- Al Hofuf road in the Eastern Province of the KSA is exposed to the encroachment of sand dunes under the influence of the prevailing northern winds most of the year, accompanied by the prevailing drought conditions. The current study aims to estimate the movement of the barchan dunes on the Al Uqayr- Al Hofuf road in Al-Ahsa Oasis from 2001 to 2019, by analyzing Landsat-7and 8 and Sentinel-2 satellite images, using spatial analysis methods within the GIS environment, In addition to the field study, in order to estimate rates of sand encroachment and its effects on the road.
The study identified three main sectors of barchan dunes, which vary in size and height, represented by large-sized dunes with a height +40 m, and small-sized dunes ranging in height from 15-30 m. The study found that the average movement of barchan dunes reached 75.5 meters during 13 years from 2001 to 2013, with an average of 6.2 m/y, while the average movement of barchan dunes in the period from 2013 to 2019 ranged nearly 57.2 meters at a rate of 9.5 m/y. Movement rates increase in barchan dunes of medium size and height (15-25 m), which characterized by its small sand grains, while movement rates decrease gradually due to the increasing of dune size and the growth of seasonal desert weeds. The study also concluded that more than 75% of the average sand movement is mainly related to the dominant northerly winds.