Document type: DU ETD
Collection: Geology Theses  
Title Hill Erosion and the Geomorphic Environment of Reclaimed Surface-Mined Hillslopes
Author(s) Soulliere, Jr., Edward J.
School/Department Department of Geography
Institution University of Denver
Degree Type Master's
Degree Name M.A.
Type of Resource text
Degree Date 1983 August
Digital Origin reformatted digital
Rights Statement All Rights Reserved
Reason for Restrictions No restrictions
Type of Restriction No restrictions
Keyword(s) Geography
Genre Dissertations, Academic
Abstract Coal is America's most abundant fossil fuel; and as the demand for energy continues to increase, it is inevitable that coal mining operations will expand. Clements (1979, p. 26) estimated that 50 percent of all new mining operations will be located in the Northern Great Plains physiographic province. Indeed, it has been estimated that 40 percent of the nation's total strippable coal reserves lie within the Powder River Basin alone (Landmarc, 1982). In terms of environmental impact, surface-mining is the most drastic of all coal extraction techniques mainly because of the area! extent of disturbance. Paone, et al. (1978, p. 17) reckoned that, nationally, surface mining disturbs 31,000 hectares (76,603 acres) of land per year, and that figure is rising. Such an area may seem minute when considering the vast areas of land within the Northern Great Plains, but it must be recognized that hydrologic impacts are not confined to the area of surface disturbance. However, surface-mining operations within this province are generally considered to have a more moderate effect on water resources than in the eastern, or arid western, coal fields (Packer, 1974, p. 1). The advantages attributable to this area stem from the fact that not only is the coal low in sulfur, but the rainfall is generally sufficient for successful reclamation. From a geomorphic standpoint, surface-mining drastically disturbs the existing balance between the landforms and the processes which have shaped them. Surface and sub-surface hydrology are altered, and erosion may be temporarily accelerated substantially above the geologic norm. With the advent of the Surface Mine Control and Reclamation Act of 1977, companies are now legally required to return the land to a pre-designated productivity by reclaiming it. Therefore, a fundamental goal of reclamation is the re-establishment of the balance between form and process. Successful reclamation is influenced by the physical, chemical, and hydrologic properties of the soils, in addition to the climatic variables (Packer, 1974, p. 1). The reclamation of disturbed lands involves the grading and shaping of spoil to approximate original contour. Topsoil is then applied and the area is planted with a suitable vegetation cover. Re-establishment of the equilibrium condition on these artificial landforms is a complicated, site-specific, and time-consuming process, the success of which depends, in part, on the control of accelerated erosion. Erosion by water is generally most severe in areas receiving approximately 360 mm. (14 inches) of effective precipitation at 10°C (50°F) (Langbein and Schumm, 1958, p. 1077). Areas receiving greater amounts of precipitation have more abundant vegetation cover which inhibits erosion; and in arid areas, despite limited vegetal cover, erosion is generally lower due to insufficient amounts of rainfall. Annual precipitation in the Northern Great Plains is often close to this value of 360 mm. (14 inches). Furthermore, the convectively-induced storms characteristic of the area release high amounts of kinetic energy and tend to exacerbate erosion problems on the artificial landforms created by reclamation. Hillslope erosion by water may be divided into two major types, sheetwash (interill) and rill erosion. Sheetwash erosion, as the term implies, is the denudation of a slope by layers of running water. Rilling, a more localized form of erosion, may be attributed to the concentration of sheetflow caused by variations in microtopographic hillslope form. Although this research will center on rill erosion, it should be recognized that the two processes are not independent of one another. Both of these erosion mechanisms are capable of rapidly removing topsoil from reclaimed slopes and rendering areas not only unsightly, but unproductive for the future. In addition, hillslope erosion significantly contributes to high sediment loads in streams.
Attached Files
Name Description MIMEType Size Downloads
du_mas_1983_Soulliere.pdf   du_mas_1983_Soulliere.pdf application/pdf 3.49MB 0

User Comments
Access Statistics: 0 Abstract Views, 0 File Downloads Detailed Statistics
Created: Wed, 23 Feb 2011, 14:00:57 UTC by John Adams . Detailed History