عقل نفوذ الثويرات : دراسة في الجيومورفولوجيا التطبيقية باستخدام تقنيات الاستشعار من بعد (RS)‎ و نظم المعلومات الجغرافية (GIS)‎

Abstract EN

The Nafud Althwairat is extension area of the sands of the Nafud great which is one of the most important formations of sand in the kingdom of Saudi Arabia, and consists mainly of geomorphology features caused by wind erosion, especially differentiated species of sand dunes, similar species.

this study aims to identify the characteristics of sand dunes resulting from wind deposits, especially in dry climatic environments, in terms of their types, morphology, and origin, factors affecting them, temporal changes in them, the extent of their risk to human activities and how to avoid them.

in order to reach these goals has been integrated techniques of remote sensing (RS) and geographic information systems (GIS) in the monitoring of sand dunes and types during four time periods consecutive (1988, 1998, 2013, 2019), was used erdas imagine a program using the maximum likelihood .

the classification accuracy came space visuals as follows: 92.56% in 1988, while it reached 95.11% visible space in 1998, and amounted to 96.74% visible space in2013, and 100% in 2019.

the results of the study indicated that the sandy formations in the area of Nafud al-Thaweirat are newly formed, and their dominant pattern is in the form of dome-shaped dunes, helped by their origins sedimentary geological formations, dry high temperature climatic conditions, scarce rain, low humidity, and high wind speed with multiple directions, this is in addition to the scarcity of vegetation.

the study also showed that the prevailing types of sand dunes in the area of Nafud al-Thuwairat in 2019 are : single domes (915.44 km2), joint domes (1036.95 km2), longitudinal and transverse domes (616.42 km2), barchan or crescentic dunes (16.35 km2), sand deposits (4211.65 km2) , and other phenomena (41.29 km2).

as for the change detection that occurred in the sand dunes during the period 1988-2019, they are very slow, as usual in the dome dunes.

the study also revealed the dangers caused by sand dunes in the area of Nufud al-Thuwairat, which are represented in agricultural lands, urban centers, roads, and desert oases.

the study made some important recommendations to mitigate the dangers of these sand dunes.