自然坡线提取及边坡近自然整形应用——以草原矿区为例

Natural slope line extraction and application of slope near-natural shaping:Taking grassland mining area as an example

东部露天矿区是我国大型煤炭基地,该地区生态环境脆弱,外排土场边坡堆积松散,易发失稳等问题。自然边坡作为长时间演化结果,具有高度的地区适宜性与地貌稳定性,对外排土场边坡的仿自然整形具有重要意义。为设计符合周边自然地貌的外排土场边坡,提出一种基于坡向迭代的自然坡线提取方法,以内蒙古胜利东二号露天矿为例,基于提取学习结果与CLiDE演化模型,构建仿自然排土场边坡并评价其抗蚀性改良效果。结果表明:1)研究区基于坡向迭代的自然坡线提取结果水平形态以曲线为主(约84%),直线样本以沟线和山脊线居多,相较于传统人为直线式的坡线提取方法,其样本提取结果更为全面。2)由于坡向的唯一性,本文基于坡向迭代的坡线提取结果有且唯一,提高了实验的可重复性。3)相较于原始边坡,各朝向近自然整形排土场边坡抗蚀性提高,其10年土壤侵蚀量平均减少约62%,斜坡倾角减少是其土壤抗水蚀能力增加的主要原因。4)在占地面积与土方量不变的条件下,由于排土场台阶中平台的缓冲作用,整形后有平台布设、斜倾角较大的边坡抗水蚀能力优于无平台布设、斜倾角较小的边坡。在后续研究中,需要充分考虑平台长度与斜坡倾角两者对边坡抗水蚀能力的正向作用。

The open-pit mining areas in northern and northeastern regions are the large coal bases in China.The ecological environment in these areas is fragile,and the slope of the external dump is loosely piled up,so it is likely unstable.By contrary,as a result of continuous evolution,natural slopes have a high degree of regional suitability and stability,and it is of great significance to imitate natural shaping of external dump slopes.In order to design an outer dump slope that conforms to the natural landform around the study area,we proposed a natural slope line extraction method based on the iteration of slope direction,and taking the No.2 open-pit mine in Xilinhaote,Inner Mongolia as an example,based on statistical theory and CLiDE evolution model,we simulated natural dumping slope and evaluated its stability improvement effect.The results show:1)The horizontal shape of the natural slope line extraction results based on the iterative aspect is mostly a curve(about 84%),and its straight-line samples are mainly ditch lines and ridge lines.Compared with the slope sample extracted by subjectively using a straight section line on the horizontal projection,the sample extraction results based on the slope direction iterative slope line extraction method are more comprehensive.2)Since the slope direction at a specific location in space is unique,the result of slope line extraction based on aspect iteration is unique,which improves the repeatability of the experiment.3)Compared with the original dump slope,the stability of each dump slope has been improved by the natural landform treatment.Its soil and water loss has decreased by an average of about 62%in ten years,and the decrease in slope is the main reason for its increasing stability.4)Under the condition that the area of the dump and the amount of earth are unchanged,due to the buffering effect of the dump platform,the soil and water retention capacity of the nearly natural shaping slope which with a platforms and a larger slope angle is better than that without a platform and a smaller slope angle.In the follow-up study,it is necessary to fully consider the positive effect of the platform length and slope angle on the slope soil and water conservation capacity.