Award Date

2009

Degree Type

Thesis

Degree Name

Master of Science in Geoscience

Department

Geoscience

Advisor 1

Zhongbo Yu, Committee Chair

Advisor 2

Michael J. Nicholl, Committee Co-Chair

First Committee Member

Michael, H. Young, Committee Co-Chair

Second Committee Member

Wanda J. Taylor

Graduate Faculty Representative

Zhonghai Ding

Number of Pages

135

Abstract

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.

Keywords

Bare soils; Chloride distribution; Chloride mass balance; Chloride transport; Eldorado Valley; Nevada; Micro-topography; Plant canopies; Root uptake; Root zones

Disciplines

Desert Ecology | Geology | Soil Science

Language

English


Share

COinS