Determination of spoil-bank erosion rates in Ohio by using interbank sediment accumulations

Denudation rates of unvegetated spoil banks in Gallia County, Ohio, were determined using sediment volumes and specific weights in four small interbank basins. Calculated rates are higher than those reported from other strip-mined areas because the spoil is unvegetated and consists mainly of friable sandstone. Spoil-bank slopes had erosion rates of 35,000 to 71,000 t · km⁻²· a⁻¹ (metric tons per square kilometre per year) with an equivalent surface degradation of 2.6 to 5.4 cm· a⁻¹ (centimetres per year). These rates show good correlation with mean slope length, which ranged from 5.8 to 12.8 m. Rates may be higher than calculated owing to loss of material by chemical weathering and subsequent leaching. The study demonstrates the suitability of simple measurements in interbank depressions to obtain average annual erosion rates for drastically disturbed landscapes.