Calculation of the Rub’ al Khali Sand Dune Volume for Estimating Potential Sand Sources

Fahad Almutlaq,Faten Nahas,Kevin Mulligan

doi:10.3390/rs14051216

Abstract

The Rub’ al Khali desert (or Empty Quarter) is the largest and perhaps most significant sand sea in the world. Located on the southern Arabian Peninsula, the dune field has remained largely unexplored owing to the harsh clime and difficult terrain. This study takes advantage of geospatial technology (interpolations, supervised classification, minimum focal statistic) to extract information from the data contained in global Digital Elevation Model (DEM)s, satellite imagery. The main objective here is to identify and map different dune forms within the sand sea, estimate the volume of sand and explore probable sources of sand. The analysis of dune color strongly suggests that the sand is not completely reworked and intermixed. If this is true, a spatial variability map of the mineral composition of the sand could be very revealing. The red sand is quite pronounced, the largest volume of sand (~36%) is associated with the yellow color class. Yellow sand covers most of the western part of the dunes field and seems to be a transitional color between red and white sand in the eastern part of the dune field. This suggests that the yellow sand might be derived from both local and regional sources, or it might be less oxidized, reworked, or have a different composition that represents a combination of red and white sand.

Highlights

A question has always existed as to the reason why such a huge amount of quartz sand exists in the Rub’ al Khali, while the surrounding geology consists largely of carbonates [1].This observation raises interesting questions with regard to the origin and age of the dunes.Given the eastward orientation and slope of the Rub’ al Khali basin and the alignment of dunes with respect to dominant northwest winds, there is a strong consensus that the sand dunes have developed from both local and regional sources [1,2]
While the analysis of the paleo drainage system suggests that the exposed Arabian Gulf is a major potential source, it seems likely that some of the red sand on the southern and western margins of the dune field is derived from local sources in the Hadramawt Arch to the south and the Sarawat Mountains in the west
The results from this study seem to confirm previous ideas regarding the source of the sand, from both the local mountains and the exposed Arabian Gulf, but it is difficult to assess how this sand is distributed throughout the dune field

Summary

Introduction

Given the eastward orientation and slope of the Rub’ al Khali basin and the alignment of dunes with respect to dominant northwest winds, there is a strong consensus that the sand dunes have developed from both local and regional sources [1,2]. In this regard, [3] was the first to suggest that wadis flowing eastward from the Arabian Shield mountains contribute local sand to the western part of the dune field. To investigate the potential sources of sand and estimate the total sand volume in the Rub’ al Khali based on sand dune color, field investigation, laboratory analysis of sediments, and visual interpretation of satellite data are required to be considered

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Discussion

Conclusion