Point locations for spatial and morphological analyses of barchans in swarms

This dataset contains the long-lat coordinates of seven points on ~6000 barchans located in six swarms.

Four of the locations are on Earth (three in the Tarfaya region of the Western Sahara, one in Mauritania).

The other two swarms are from high latitudes of the northern hemisphere of Mars.

In each location between 850 and 1112 barchans were measured.

The measurements were carried out manually by Dominic T Robson and Andreas CW Baas according to the method described in

Robson, D. T., Annibale, A., & Baas, A. C.W. (2022). Reproducing size distributions of swarms of barchan dunes on Mars and Earth using a mean-field model. Physica A: Statistical Mechanics and its Applications, 606, 128042.

The included metadata file lists the copyrights and dates (DD/MM/YYYY) for the imagery used, all imagery was accessed through Google Earth.  

The metadata file also includes descriptions of the format of the data.  The data themselves are provided in separate comma delimited files for each location.  Only the bedforms identified as barchans are included although other bedforms in the locations were also measured (see Robson et al. Physica A (2022)).

Using the seven points recorded for each dune it is possible to calculate:

Body length

Total length

Horn lengths

Total width

Horn-to-horn width

Port flank width

Starboard flank width

Slipface length

Dune orientation

The area of the polygons formed by the points also provides an estimate for the basal area of the dune though it is not a perfect match.

We hope that these data will be of use to those seeking to study the morphology, size, asymmetry, and spatial distribution of barchans in swarms.

Dominic T Robson and Andreas CW Baas.