Megadune Development Under a Unidirectional Wind Regime: The Case of Megabarchans in Southwestern Morocco

Maciej Dłużewski; Joanna Rotnicka-Dłużewska; Karolina Krawczyk; Lidiya Dubis

doi:10.48128/pisg-2026-71.3-01

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Megadune Development Under a Unidirectional Wind Regime: The Case of Megabarchans in Southwestern Morocco

Prace i Studia Geograficzne

Volume 71 (2026): Issue 3 (September 2026)

By: Maciej Dłużewski , Joanna Rotnicka-Dłużewska , Karolina Krawczyk and Lidiya Dubis

Open Access

|Sep 2026

Abstract

This study investigates the morphology, dynamics, and sediment characteristics of the Al-Ghord Lahmar megabarchans in SW Morocco. These megadunes developed under unidirectional trade-wind regime and are supplied by beach-derived sand. The megabarchans reach up to 30 m in height and about 1 km in length and are superimposed by barchanoid ridges. Megabarchans migrate at approx. 3 m/yr, while the superimposed dunes move 15–17 m/yr, indicating sediment recycling across the dune surface. Grain-size analyses reveal very well-sorted fine sands with limited spatial variability, whereas grainshape measurements indicate intensive sediment mixing and prolonged aeolian reworking. The results suggest that megabarchan growth depends on the interaction of persistent winds, continuous sediment supply, and ephemeral flooding, which enhances moisture retention and sediment trapping. Unlike relatively stable star and linear megadunes, megabarchans are highly mobile and sensitive to environmental change.

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Articles in this issue

DOI: https://doi.org/10.48128/pisg-2026-71.3-01 | Journal eISSN: 2543-7313 | Journal ISSN: 0208-4589

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Language: Polish, English

Page range: 7 - 23

Submitted on: Aug 3, 2026

Accepted on: Sep 2, 2026

Published on: Sep 21, 2026

Published by: University of Warsaw

In partnership with: Paradigm Publishing Services

Publication frequency: 4 issues per year

Keywords:

compound dune,

coastal megabarchans,

Related subjects:

History,

Topics in history, other,

Social sciences,

Social sciences, other

© 2026 Maciej Dłużewski, Joanna Rotnicka-Dłużewska, Karolina Krawczyk, Lidiya Dubis, published by University of Warsaw
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Volume 71 (2026): Issue 3 (September 2026)