Abstract:【Objective】Slopes of coal mine dump are characterized by severity of soil erosion, diversity of erosion type and complexity of erosion processes. The law of soil erosion on the slopes is different from that on slopes of original landform in mining areas. In order to explore effects of revegetation controlling soil erosion on slopes of coal mine dumps, survey of a dumping site was carried out in the Yongli Coal Mining of Zhungeer Banner, Inner Mongolia. 【Method】The survey, using the quadrat survey procedure, covered a bare slope as CK, and slopes revegetated in the pattern of Salix cheilophila+ Hippophae rhamnoides Linn. And Astragalus adsurgens Pall (SHA) or Salix heilophila and Astragalusadsurgens Pall (SA), for a different time period of 1a, 3a or 5a, in an attempt to explore spatial and temporal effects of the revegetation on rill development on the slopes. 【Result】Results show: (1) on all the slopes, the rills varied in the range of 4-8 cm in width and in the range of 2-4 cm in depth in the first year, on the slopes of CK, SHA and SH did in the range of 4-8 cm, 8-12 cm and 4-8 cm in width, respectively, and all in the range of 4-6 cm in depth in the third year, and on the slopes of CK and SHA, they did in the range of 8-12 cm in width and in the range of 4-6 cm and 8-14 cm in depth respectively; (2) Over the five years, the rills on Slopes CK, SHA and SA varied in the range of 7.57-11.35 cm, 7.58-13.31 cm and 5.57-6.14 cm, respectively, in mean width, in the range of 3.38-6.23 cm, 4.19-10.34 cm, and 2.59-4.24 cm, respectively in mean depth, and in the range of 1.52-5.25 m?m-2, 1.42-1.68 m?m-2 and 1.88-2.25 m?m-2, respectively, in density; (3) For the first year, the rills in all the slopes increased with length of the slope in ratio of width and depth quite sharply, but with the time going on, they showed a decreasing trend in the ratio, while they varied in an increasing trend in rill density and rill erosion amount with length of the slope; and (4) Compared with CK, SHA and SA decreased the slope rill erosion modulus by 25.0% and 25.86%, respectively, showing little erosion controlling effect in the first year, but they did by 61.73% and 35.31% respectively, showing significantly enhanced erosion controlling effect.【Conclusion】SHA and SA come to be effective only in the third year and on. The rills on Slopes SHA and SA varied in the range of 8 -12 cm and 4-8 cm, respectively, in width and in a range of 4-6 cm and 2-6 cm, respectively, in depth, which indicates SA is more effective in controlling development of rills, in terms of width and depth of rills. And the rills on Slopes SHA and SA varied in the range of 1.42-1.68 m?m-2 and 1.88-2.25 m ?m-2, respectively, in density, which suggests that SHA is more effective in terms of number of rills per unit area. Both of the effects become more significant with increasing distance from the top of the slope. Erosion modulus was 1.15% lower in SHA than in SA in in the first year, and then came up to 1.55 kg?m-2?a-1 and 2.62 kg?m-2?a-1, respectively, in the two, suggesting that SHA is more effective in controlling erosion. All the findings in this survey may serve as a scientific basis and theoretical guidance for rational revegetation of mine dump slopes.
