Date of Award

Spring 6-14-2025

Document Type

Undergraduate Honors Thesis

Degree Name

B.A. in Environmental Science

Organizational Unit

College of Natural Science and Mathematics, Geography and the Environment

First Advisor

Eric Boschmann

Second Advisor

Helen Hazen

Third Advisor

Michael Keables

Fourth Advisor

Michael Ketterer

Copyright Statement / License for Reuse

All Rights Reserved
All Rights Reserved.

Keywords

Sedimentation, Fluvial processes, Suspended sediments, Anthropogenic pollution, Sediment tracing, Inductively coupled plasma mass spectrometry (ICPMS), Kansas, Urbanization, Erosion

Abstract

This exploratory study investigates whether bulk elemental analysis of sediment samples using inductively coupled mass spectrometry (ICP-MS) can reveal chemical signatures that identify anthropogenic contributions to sedimentation and increased fluvial suspended sediment loads, and whether these contribution sources can be identified. Human activity, urbanization, and changes in land use increase erosion, resulting in higher-than-natural suspended sediments (SS) in waterways and increasing sedimentation in reservoirs across the state of Kansas. These threats to freshwater storage capacity are especially urgent given the projected rise in freshwater demand in the Great Plains region driven by climate change. Understanding the origin of anthropogenic SS loads allows for implementation of more effective mitigation strategies. Therefore, several SS tracing methods have been developed, including “sediment fingerprinting” (using distinct chemical tracers to source SS); the basis of this study.

ICP-MS was used to determine the elemental constituents and concentrations of unknown soil samples across Johnson County, Kansas. These samples were sourced from road dust, construction site soil, vegetated areas, streambanks, and in-stream sediment traps from watersheds with urban land cover ranging from 15% to 90%. The ICP-MS analysis was performed blind using internal standard normalization, mass scaling, and certified reference materials to quantify elemental concentrations. Elevated levels of elements such as tungsten (W), cadmium (Cd), zinc (Zn), and lead (Pb) were found in road dust samples, while elements like aluminum (Al) and rubidium (Rb) were depleted, indicating distinct anthropogenic fingerprints compared to other sediment sources. The observed concentration patterns provide insight into suspended sediment origin, especially in the case of road-runoff, without the use of statistical modelling. The distinct characteristic patterns from this study can be used in future modeling and statistical analysis to assist in the apportionment of sediment sources, support tailored mitigation efforts and targeted best management practices (BMPs), and ultimately help to reduce source sediment pollution and preserve freshwater storage capacity in the region.

Copyright Date

5-4-2025

Publication Statement

Copyright is held by the author. User is responsible for all copyright compliance.

Rights Holder

Kiena Campbell

Provenance

Received from author

File Format

application/pdf

Language

English (eng)

Extent

46 pgs

File Size

5.7 MB

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