Date of Graduation

Summer 2020

Degree

Master of Science in Geospatial Sciences

Department

Geography, Geology, and Planning

Committee Chair

Robert Pavlowsky

Keywords

Bank Erosion, Mining, Sediment Budgets, STEPL, Nonpoint Source Pollution, Ozark Highlands, Missouri

Subject Categories

Geomorphology

Abstract

In-channel sources and storages of fine-sediment such as in banks and bars can influence sediment loads and overall geomorphic activity in stream systems. However, in-channel processes and effects on sediment load are rarely quantified in geomorphic or water quality studies. This study uses a sediment budget approach to assess the influence of bank erosion and bar deposition on fine sediment loads in Mineral Fork (491 km2) and Mill Creek (133 km2) watersheds located in the Ozark Highlands in Washington County, Missouri. These watersheds were disturbed by historical lead and barite mining which included the construction of large tailings dams across headwater valleys. USEPA’s Spreadsheet Tool for Estimating Pollutant Loads (STEPL) was used to quantify suspended sediment delivery from upland areas and assess land use-load relationships. Aerial photographs from 1995 and 2015 were used to identify spatial patterns of erosion and deposition in bank and bar forms. LiDAR was used to characterize the channel network and determine bank and bar heights. Field measurements were used to ground-truth bank and bar heights and fine-sediment composition of alluvial deposits. Historical tailings dams capture runoff from 27% of Mineral Fork and 28% of Mill Creek drainage areas, trapping 38% and 26% of the suspended sediment load annually, respectively. The total annual sediment yield for Mineral Fork watershed was 92 Mg/km2 /yr with 55% released by bank erosion and <1% reduced by bar storage. The sediment yield for Mill Creek was 99 Mg/km2 /yr with 33% released by bank erosion and 24% reduced by bar storage. These results indicate that in-channel processes are important contributors to sediment yields in these watersheds.

Copyright

© Kayla Ann Coonen

Open Access

Included in

Geomorphology Commons

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