Multi-fractal characteristics of reconstructed landform and its relationship with soil erosion at a large opencast coal-mine in the loess area of China

Abstract

Post-mining dumps are typical artificial landforms, with original natural features of soil, topography and vegetation radically altered, and soil and water conservation capacity declined accordingly. In this study, the geomorphic characteristics and soil erosion of reconstructed landforms and their relationships in opencast coal mines are studied. The elevation relief features were described using multi-fractal methods, soil erosion rates were evaluated utilizing the revised universal soil loss equation (RUSLE), and the correlations between geomorphic multi-fractal parameters and soil erosion rate were analyzed within a study area of three soil dumps in the Shanxi Pingshuo Antaibao opencast coal-mine of China. The results show that reconstructed landform in opencast coal mines have multi-fractal characteristics. Generalized dimensions (D0, D1, ΔD and D1/D0) and singularity spectra (α0, Δα and Δf) quantify reconstructed geomorphic features. Soil erosion in the sub-areas is slight, indicating that reclamation measures have alleviated soil erosion exacerbated by mining. Geomorphic multi-fractal parameters reflect the differences of soil erosion rate, the increasing trend of D0, D1 and α0 are consistent with that of average annual soil loss rate. It is feasible to apply these parameters to reflect soil erosion of reconstructed landforms. This study provides a new perspective for portraying the reconstructed geomorphic features and soil erosion on opencast coal-mine dumps.