Date of Graduation

Spring 2016

Degree

Master of Natural and Applied Science in Geography, Geology, and Planning

Department

Geography, Geology, and Planning

Committee Chair

Robert Pavlowsky

Abstract

Historical mining in the Old Lead Belt resulted in lead (Pb) contamination of floodplain soils for over 170 km along the Big River in southeastern Missouri. The overall pattern of contamination are understood. However, Pb distribution across floodplain surfaces has not been investigated at the scale needed for site-level remediation planning. The goal of this project is to examine spatial distribution of Pb with more detail and identify the role of geomorphic processes. Predictive models are needed to evaluate factors affecting Pb distribution such as elevation, distance from the channel, and geochemistry. This study evaluates Pb distribution at three ~1km sites on the Big River with varying floodplain conditions: (1) human-altered topography, (2) narrow valley and, (3) wide valley. Surface soil samples were collected to quantify Pb, geomorphic maps were created using LiDAR, and spatial patterns were analyzed using regression models. Results show that Pb levels at the three sites pose an ecological problem. The most effective predictive model was created at the narrow floodplain site using distance from the channel, elevation, and Fe as independent variables. Less sensitive models were created at the two other sites which had more complicated geomorphological characteristics and less variability in Pb. Using landform/soil series associations and examining the influence of watershed-scale factors such as valley width and proximity to source are likely more effective approaches for understanding Pb distribution on Big River floodplains.

Keywords

geomorphology, mining contaminates, floodplains, Missouri, GIS

Subject Categories

Environmental Sciences | Geomorphology

Copyright

© David Bower Huggins

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Open Access

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