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Accueil du site → Doctorat → Australie → 2007 → Effects of Soil Crusts on the Erodibility of a Claypan in the Channel Country, South-West Queensland, Australia

Griffith University (2007)

Effects of Soil Crusts on the Erodibility of a Claypan in the Channel Country, South-West Queensland, Australia

Craig L. Strong

Titre : Effects of Soil Crusts on the Erodibility of a Claypan in the Channel Country, South-West Queensland, Australia

Auteur : Craig L. Strong

Université de soutenance : Griffith University

Grade : Doctor of Philosophy (PhD) 2007

Résumé
This thesis explores the role of cyanobacterial crusts in controlling the aeolian erodibility of arid soil surfaces. Soil erodibility estimates are commonly derived from sediment trap measurements or field wind-tunnel simulations. Such estimates are often difficult to relate to crust types and conditions because of the intricate spatial variation inherent with crusts. Similarly, empirical wind-erosion models across a range of spatial scales often fail to incorporate a crust parameter simply because of the complexity associated with both spatial and temporal variations in crustal attributes. The soils of the Channel Country, western Queensland, the site of this study, have intricate mosaics of biological and physical crusts. These arid soils are frequently affected by wind erosion and the role that the presence of the crusts has in controlling erodibility is a largely unknown. The aim of this study has been to address this knowledge gap. It was found that the spatial heterogeneity of the surface features described for the study area claypan supported a diverse range of crust types and cover levels. This diversity varied at sub metre increments. Such spatial diversity is beyond the sensitivity of most common measurement or modelling approaches used in wind erosion research. To overcome this, a specialised Micro Wind Tunnel (MWT) was developed providing a reliable and practical solution measuring erodibility between different crust types. The MWT successfully provided laminar horizontal airflow with and without added saltation material, to specific crust types. Importantly, the size of the MWT was appropriate to the spatial heterogeneity of crust types

Mots clés : Cyanobacterial crusts, Arid soil surfaces, Micro Wind Tunnel, Erodibility, Channel country Queensland

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Page publiée le 29 décembre 2014, mise à jour le 31 mai 2017