Authors: Kayla Coonen*, Ozarks Environmental and Water Resources Institute
Topics: Geomorphology, Geographic Information Science and Systems, Physical Geography
Keywords: Bank Erosion, GIS, Fluvial Geomorphology, Watersheds, Mining, Nonpoint Source, Missouri
Session Type: Poster
Start / End Time: 8:00 AM / 9:40 AM
Room: Lincoln 2, Marriott, Exhibition Level
Presentation File: No File Uploaded
Non-point source pollution is the leading source of water-quality impacts to surface water in the United Sates. The Clean Water Act (Section 303d) specifies that watershed models should be used to develop Total Maximum Daily Loads to determine pollutant load limits and evaluate plans for best management practices. This study aims to develop a nonpoint source model for sediment and nutrients using USEPA’s Spreadsheet Tool for Estimating Pollutant Loads (STEPL) for Mineral Fork (491 km2) and Mill Creek (133 km2) watersheds in Washington County, Missouri. These watersheds offer a challenge because the drainage network was disturbed by historical barite mining with pits, ponds, and tailings dams. This poster reports preliminary results on the methods and spatial analysis of bank erosion rates to provide input data to support NPS modeling. Historical aerial photographs from 1990 to 2015 are compared to identify bank erosion and deposition trends over 25 years by digitizing the active channel. LiDAR is used to develop cross-sections along disturbed areas to determine bank height. The main channel of Mineral Fork is 28.1 km long with 65% of its length having at least one bank eroding. Mill Creek is 22.8 km long and also has 65% of its length eroding. Maximum erosion rates for individual cut-bank features exceeded 3 m/yr. The net mass of sediment lost to the channel by bank erosion was 12 Mg/yr in Mineral Fork and a net gain of 0.19 Mg/yr in Mill Creek. These sediment yields only include about 1/5 of the channel network.