Date of Graduation

2015

Document Type

Dissertation

Degree Type

PhD

College

Statler College of Engineering and Mineral Resources

Department

Civil and Environmental Engineering

Committee Chair

Leslie C Hopkinson

Committee Co-Chair

John D Quaranta

Committee Member

Vladislav Kecojevic

Committee Member

Brijes Mishra

Committee Member

Hema Siriwardane

Abstract

Surface mining and valley-fill practices often lead to environmental impacts including headwater stream loss, increased flooding risk, and degraded downstream water quality. Geomorphic landform design (GLD) is an innovative reclamation technique proposed to lessen the impacts associated with surface mining and valley-fill activities. GLD incorporates mature landform shapes and created stream channels on site, imitating the function of the undisturbed landscape. The purpose of this research was to model GLDs in mountainous terrain and evaluate the hydrologic response and erosion potential of GLD in surface mining application. Computer modeling of valley-fill designs using geomorphic landform principles of a study site in southern West Virginia was performed. Four enhanced GLDs were created for application on new and previously constructed valley fills: 1) regional data GLD for new valley fill, 2) retrofit GLD for existing conventional valley fill, 3) regional data GLD enhanced with bench pond retention structures, and 4) regional data GLD enhanced with valley pond retention structures. Soil erosion was evaluated using the Revised Universal Soil Loss Equation (RUSLE) for the regional data GLD, conventional valley fill, and the undisturbed site during different stages of the reclamation process. Soil loss rates were highest (conventional: 123.2 t ha-1 yr-1; GLD: 204.3 t ha-1 yr-1) during the post-mining, pre-vegetation condition along the stream channels and steep slopes (slope >50%). Erosion rates were lowest for the post-reclamation, long term condition (conventional: 35.6 t ha-1 yr-1 ; GLD: 41.8 t ha-1 yr-1) along the ridges. Model predictions of soil erosion rates and spatial distributions illustrated areas of increased erosion potential for future minimization and reclamation method/management practices improvement. Hydrologic response modeling was performed for a watershed in southern West Virginia disturbed by surface mining and valley-fill activities to predict impacts on stream flows at the landscape scale. Incorporation of GLD reclamation methods did not result in substantial changes in current (2011-2020) or future (36500-2050) stream flowrates (≤3.3% difference) or stormflow volumes (≤2.1% difference). The differences in flows and volumes could be used for mitigation plans in watersheds disturbed by surface mining and valley-fill activities.

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