Analysis of dune morphology within the Rub’ al Khali using geospatial technology

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. While several studies have mapped the different dunes forms within the Rub’ al Khali, most of this research is based on field expeditions, the visual interpretation of air photos or the visual interpretation of satellite imagery. To build upon this previous work, this study takes advantage of geospatial technology to extract information from the data contained in global DEMs, satellite imagery and weather forecast models. The main objective here is to: 1) identify and map the different dune forms within the sand sea, 2) estimate the volume of sand and explore probable sources of sand, and 3) relate the different dune forms to the prevailing wind regime. The results from this study are very enlightening. In the first part of the study, new maps are generated showing shaded relief, the spatial variability in dune height, the spatial variability in dune texture, and profile graphs are created to examine the dune surface in cross-section. In the second part of this study, satellite imagery is analyzed to highlight differences in the color of the sand, and digital elevation models are analyzed to map the paleodrainage system, the desert floor beneath the dunes, and calculate the volume of sand. Lastly, in the third part of this study, the output from weather forecast models is used map the spatial and temporal variability in wind speed, the pathways of sand movement through the dune field and the directional variability in sand transport.