Date of Graduation

2017

Document Type

Thesis

Degree Type

MS

College

Statler College of Engineering and Mineral Resources

Department

Civil and Environmental Engineering

Committee Chair

Leslie Hopkinson

Committee Co-Chair

Lance Lin

Committee Member

John Quaranta

Abstract

Vegetation cover is required on disturbed land resulting from construction activities. The West Virginia Division of Highways (WVDOH) specifications for seeding and mulching currently includes seed mixtures that contain species that are considered highly invasive by the West Virginia Division of Natural Resources (WVDNR). This work evaluated the use of experimental seed mixtures at roadside locations by considering two major objectives: i) evaluating long-term performance of experimental mixtures over multiple growing seasons, and ii) investigating sediment yield from vegetation cover practice.;First, vegetation growth and persistence from four small-scale field plots were monitored through the second and third growing seasons. The first field plot compared vegetation resulting from current WVDOH seed mixtures to new native and low invasive experimental seed mixtures. The second field plot tested experimental seed mixtures and WVDOH mixtures at a high elevation location to determine success of an experimental high elevation mixture. The third field plot was prepared by varying seed bed preparation techniques: i) planting in existing soil using hydraulic erosion control product, ii) planting in existing soil using straw mulch, iii) planting in topsoil using hydraulic erosion control product, and iv) planting in topsoil using straw mulch. The final plot was prepared by varying soil amendments (e.g. planting in existing soil, topsoil, and two hydraulic growth mediums) and compared resulting vegetation of an experimental mowable areas mixture planted throughout the entire plot. All experimental mixtures, except experimental high elevation mixture, were found to perform as well or better than current WVDOH seed mixtures. There was no significant difference between seed bed preparation with respect to resulting ground cover or biomass. Soil amendments were found to be comparable alternatives to topsoil and are being recommended to WVDOH specifications.;Second, runoff collection devices were constructed and deployed at one subplot of each of the four varying seed bed preparations. The traps collected runoff from storm events, and the runoff was analyzed for nutrients and sediment yield. Field-measured sediment yield was compared to estimated sediment yield that was calculated using the Modified Universal Soil Loss Equation (MUSLE). Limitations of the study did not allow accurate comparisons between the MUSLE and actual sediment yield. However, lack of runoff during one storm event proved that vegetation from all seed bed preparations completely prevents runoff from small storm events (≤ 0.5 in (1.27 cm)). Future work should include monitoring of experimental mixtures over further growing seasons.

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