Je. Mcintosh et Ri. Barnhisel, ERODIBILITY AND SEDIMENT YIELD BY NATURAL RAINFALL FROM RECONSTRUCTEDMINE SOILS, Soil science, 156(2), 1993, pp. 118-126
Standard erosion plots, 4.6 m x 22.1 m with a 9% slope, were establish
ed at the Alston Surface Mine in Ohio County, Kentucky. Topsoil, subso
il, and mine spoil were reconstructed according to contemporary reclam
ation techniques using bulldozers and scraper pans. The following para
meters were evaluated under natural rainfall conditions: runoff, erodi
bility, and sediment yield. Mine spoil yielded significantly greater r
unoff volumes, compared with reconstructed topsoil and subsoil. Averag
e curve numbers (CN) were 89.1, 90. 1, and 94.7 for bare topsoil, subs
oil, and mine spoil, respectively. The subsoil plot generated the larg
est amount of sediment and was significantly more erodible than topsoi
l and mine spoil. The average annual erodibility (K) factor was .046 f
or topsoil, .067 for subsoil, and .051 for mine spoil, with units of M
g ha h (ha MJ mm)-1. Erodibility of the mine spoil in this study was m
ore than twice that measured from an earlier rainfall simulation study
at this same site. Differences in the degree of physical weathering w
ere believed to be the primary contributing factor and, therefore, hav
e important implications when assessing the erodibility of highly weat
hered spoil materials (e.g., abandoned mine lands). Compared with the
soil interpretation record's K factor estimate for the soil series eva
luated in this study, the reconstructed topsoil was not inherently mor
e erodible than when existing in its natural, undisturbed condition. T
herefore, factors that the mine operator can control (e.g., slope, veg
etative cover, management practices) will likely have a greater impact
on whether erosion losses from reconstructed soils are significantly
greater than losses that occur under pre-mining conditions.