Erodibilities and Eroded Size Distribution of Western Kentucky Mine Spoil and Reconstructed Topsoil

摘要

Standard erosion plots (4.6m by 22.1m on 9 percent slope) were constructed on the Alston Surface Mine of Peabody Coal Co. in western Kentucky to evaluate the effects of placement technique and density on the erodibility and eroded size distribution from mine spoil and reconstructed topsoil. Plots were constructed with a dozer and scraper pan from shale spoil material, topsoil (A horizon) and subsoil (B and C horizon mixture) using soils stockpiled at the Alston Surface Mine. Plots were evaluated under fallow conditions with a tilled plot surface and two compacted conditions. One compacted condition was generated by tracking the surface with a dozer and rolling with a loaded scraper pan. The second was generated by tolling the surface with a solid wheel compactor. Rainfall was supplied with the KY Rainfall Simulator at a rate of 63.5 mm h-1 with the plots in 3 different soil moisture conditions; dry, field capacity, and very wet. Runoff was evaluated for flow rates, sediment concentrations, and aggregate and primary particle size distributions. Sediment yields and the Universal Soil Loss Equation EI30 indexes were calculated from the data for each plot. The erodibility was calculated from the tilled plot data using a weighted soil loss and EI30 value from the dry, field capacity and wet runs, and a cover management factor calculated for every other condition.