Leslie Hopkinson

Streambank shear stress estimates using turbulent kinetic energy

In tidal environments, the boundary shear stress (BSS) is directly proportional to the turbulent kinetic energy, with a reported proportionality coefficient of 0.19. This coefficient was calculated using velocity time series to determine Reynolds stresses and, ultimately, to estimate the BSS. The coefficient has not been evaluated using direct measurements of BSS or for environments other than tidal systems. This laboratory flume study examines the validity of this relationship for a sloping streambank with and without vegetation. BSSs and near-bank Reynolds stresses were calculated using a constant temperature anemometer and velocity measurements, respectively. The coefficient ranged from 0.11 to 0.53 when calculated with the measured values of BSS, and 0.09 to 0.37 when calculated with Reynolds stresses. The variation was attributed to differences in turbulence generation, coefficient development, and instrumentation.

GEOMORPHIC LANDFORM DESIGN PRINCIPLES APPLIED TO AN ABANDONED COAL REFUSE PILE IN CENTRAL APPALACHIA

Abstract. Geomorphic landform design is a reclamation technique that may offer opportunities to improve aspects of mine reclamation in Central Appalachia. The design approach is based on constructing a steady-state, mature landform condition and takes into account the long-term climatic conditions, soil types, terrain grade, and vegetation. Geomorphic reclamation has been applied successfully in semiarid regions but has not yet been applied in Central Appalachia. This work describes a demonstration study where geomorphic landforming techniques are being applied to a coarse coal refuse pile in southern West Virginia, USA. The reclamation design includes four geomorphic watersheds that radially drain runoff from the pile. Each watershed has one central draining channel and incorporates compound slope profiles similarly to naturally eroded slopes. Planar slopes were also included to maintain the impacted area. The intent is to reduce infiltration rates which will decrease water quality treatment costs at the site. The excavation cut and fill volumes balanced to approximately 250,000 yd. This volume is comparable to those of more conventional refuse pile reclamation designs. If proven successful then this technique can be part of a cost-effective solution to improve water quality at active and future refuse facilities, abandoned mine lands, bond forfeiture sites, landfills, and major earthmoving activities within the region.

Evaluation of revegetation techniques for roadside construction sites

Vegetation is often used to control erosion on right-of-way construction sites, but disturbed conditions provide challenges. This research evaluated the impact of common techniques for preparing seedbeds. The study assessed the use of topsoil, and the use of a hydraulic erosion-control product was compared to straw. Experimental seed mixtures were evaluated to understand how native and non-native seeds performed. The intent was to identify critical practices to use in general seeding and mulching specifications. A plot study was conducted comparing vegetation established during one growing season. Treatments included combinations of seed mixture, topsoil treatment, and mulch types. Three seed mixtures were considered: (1) currently used mixture, (2) a warm-season experimental mixture, and (3) a cool-season experimental mixture. Plots with topsoil and no topsoil were compared, and both straw and hydraulic erosion control products were considered. Ground cover, compaction, and biomass were evaluated. Results suggest that alternative seed mixtures that include native and low-threat-level species can provide adequate cover to meet permitting requirements in the first growing season. The warm-season seed mixture provided less cover than the other two mixtures after eight days, but no differences were determined in ground cover among the three seed mixtures at the end of the growing season. Initial germination was improved with hydraulic mulch, but long-term cover was equivalent between hydraulic and straw mulch. Topsoil application would not be recommended if the soil contains undesirable species, and the use of organic amendment products may be more desirable than topsoil alone; however, specifications need to allow the use of these products.

The Assessment of Instruments for Detecting Surface Water Spills Associated with Oil and Gas Operations

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Simulating the hydrologic response when streams are incorporated in valley-fill design

Abstract The geomorphic landform design (GLD) approach has the potential to incorporate stream networks into valley-fill reclamation. This work modelled the potential hydrologic response of GLD by evaluating storm response as well as flooding of the receiving reach of one West Virginia valley fill in several construction phases (i.e. pre-mining, conventional design and GLD). The GLD during construction condition resulted in peak flowrates that were more than twice the undisturbed pre-mining condition, but peak flowrates reduce to pre-mining conditions over time. A GLD that included surface ponds was presented to offer on-site streamflow. A retrofit example was presented to improve bond failing sites.

Initial study of potential surface water quality impacts of horizontal drilling in the Marcellus shale

ABSTRACT This research assessed impacts of drilling for gas in the Marcellus shale by monitoring water quality. Both a stream with an active drilling operation and a reference stream were monitored. Differences at the active reach were detected in turbidity, pH, conductivity, total dissolved solids, Sr, Ca, Cl, Na, Mg, alkalinity, and SO4. Differences were largely attributed to an expanded roadway, and the ranges of most measured parameters were within range of water quality criteria for West Virginia.