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University of Nevada Las Vegas (2009)

Effects of plant uptake and micro-topography on chloride transport in arid soils

Wenming Nie

Titre : Effects of plant uptake and micro-topography on chloride transport in arid soils

Auteur : Wenming Nie

Université de soutenance : University of Nevada Las Vegas

Grade : Master of Science in Geoscience 2009

Résumé
Chloride concentration profiles to depths of 1 m were evaluated on a young alluvial fan in Eldorado Valley, NV. It was found that chloride beneath plant canopies were 11 to 222 times higher than adjacent (1 - 2 m away) bare soil locations. Two-dimensional numerical simulations using HYDRUS 2D/3D model were used to further explore the impact of plants on chloride transport. The simulation results indicated that lateral flow driven by root uptake concentrated chloride toward root zones, leading to the accumulation of chloride under plant canopies. Results also suggest that locally micro-topography can have a substantial impact on chloride migration, as runoff into locally low areas (swales) can push chloride deeper into the soil profile than in adjacent high areas (bars). Hence, the uneven distribution of chloride in microsites should be considered when select field sampling sites for paleoflux and age estimates using chloride mass balance method.

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Page publiée le 17 septembre 2010, mise à jour le 31 octobre 2018