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Accueil du site → Doctorat → Royaume-Uni → 1997 → Relationships between sediment, moisture and soil crust characteristics in arid environments

University of Durham (1997)

Relationships between sediment, moisture and soil crust characteristics in arid environments

Kirk, Alastair James.

Titre : Relationships between sediment, moisture and soil crust characteristics in arid environments.

Auteur : Kirk, Alastair James.

Université de soutenance : University of Durham

Grade : Doctor of Philosophy (Ph.D.) : 1997

Résumé
From a geomorphological point of view, arid environments are characterised by complex process interactions and suites of landforms which can be sensitive to their controlling parameters. Relationships between sediment, moisture and soil crust characteristics are no exception. Field research and a programme of laboratory study were undertaken between 1993 and 1995 on the soils of the northern Badia of Jordan to advance knowledge on aspects of arid zone soil dynamics, with a particular emphasis on crusting. The research focuses primarily on the effect soil crusts have upon the equilibrium of sediment dynamics at a hillslope and a high ridge-furrow scale. The implications of the crust upon moisture storage within the surface layers of the soil are examined and the spatial characteristics which arise due to management practices and climate variables considered. A new, non-destructive technique to examine moisture content in dryland soils has been developed and tested. Monitoring has taken place to examine the effects of irrigation upon the surface characteristics of the surrounding soil, with special reference to evaporation fluxes within a furrow and the associated precipitation of salts. The role of small-scale topography tends to be underestimated. Different types of crust have been studied from various topographic locations. Fabric and porosity have been examined, to increase understanding of micro-scale depositional and erosional processes. A new method of tracing fine material through the upper soil profile has been developed. As crusts form, the tracer can be used to monitor the movement of fines, permitting a much clearer understanding of soil and water dynamics during rainfall events.

Mots clés : Micromorphology ; Topography ; Soil porosity Geography Soil science Geography Soil science

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