陕北煤矿区不同形态的采动地裂缝对土壤可蚀性的影响

Effects of mining ground fissures of different shapes on soil erodibility in Northern Shaanxi coal mining area

  • 摘要: 黄河流域中游作为国家水土流失重点预防和治理区,解决其煤炭开采与水土保持间的矛盾对于矿区生态环境保护与高质量发展具有重要意义。以陕北柠条塔井田北翼采动地裂缝发育区内"平开式"、"台阶式"、"组合式"3种典型形态的采动地裂缝及其周边土壤(水平距离100 cm以内、垂直深度20 cm以浅)为研究对象,测定了土壤机械组成和有机质含量,基于EPIC模型计算了土壤可蚀性K值,分析了不同形态采动地裂缝影响下土壤机械组成和有机质质量分数的空间变化特征,解译了不同形态采动地裂缝在小空间尺度下的水土流失效应。结果表明:①"平开式"、"台阶式"、"组合式"3种形态的采动地裂缝均会导致其周围土壤黏粒质量分数、有机质质量分数明显下降和土壤可蚀性K值明显增大,土壤黏粒质量分数的平均降幅依次为21.50%、43.93%、58.70%(p<0.05),土壤有机质质量分数的平均降幅依次为45.72%、61.79%、78.66%(p<0.05),土壤可蚀性K值的平均增幅依次为12.49%、17.82%、32.35%(p<0.05),且均以水平负效应为主;②在相同水平距离及垂直深度下,"组合式"裂缝降低周围土壤黏粒质量分数、有机质质量分数和提升土壤可蚀性K值的能力显著高于"平开式"和"台阶式",排序均为"组合式"> "台阶式" >"平开式";③基于指数函数分别建立了3种形态采动地裂缝影响周围土壤可蚀性K值的作用范围预测模型,发现不同形态采动地裂缝提升周围土壤可蚀性的作用范围基本在155 cm以内,再结合差异显著性对比分析,明确了"平开式"、"台阶式"、"组合式"采动地裂缝提升周围土壤可蚀性的关键作用范围依次为40、60、100 cm以内,其可作为陕北矿区采动地裂缝小空间尺度下水土流失效应的精准防控靶区。

     

    Abstract: The middle reaches of the Yellow River Basin, as a national key prevention and control area of soil and water loss, is of great significance to solve the contradiction between coal mining and soil and water conservation for the protection of ecological environment and high-quality development of mining areas. The mechanical composition and organic matter content of soil were measured, and the soil erodibility K value was calculated based on EPIC model. The spatial variation characteristics of soil mechanical composition and organic matter content under the influence of different forms of mining ground fissures were analyzed, and the soil and water loss effect of different forms of mining ground fissures on a small spatial scale was interpreted. The results showed that:① the mining ground fissures in three forms of "horizontal opening", "step type" and "combined type" led to the obvious decrease of soil clay content and organic matter content and the obvious increase of soil erodibility K value. The average decrease of soil clay content was 21.50%, 43.93% and 58.70% (p<0.05), respectively, and the average decrease of soil organic matter content was 45.72%, 61.79% and 78.66% (p<0.05), respectively. The average increase of soil erodibility K value was 12.49%, 17.82% and 32.35% (p< 0.05), respectively and the horizontal negative effect was the main effect. ② At the same horizontal distance and vertical depth, the ability of "combined" cracks to reduce soil clay content, organic matter content and increase soil erodibility K value was significantly higher than that of "open" and "stepped" cracks, and the order was "combined type" > "stepped type" > "flat type". ③ Based on the exponential function, the action range prediction models of three forms of mining ground fissures affecting the K value of surrounding soil erodibility were established respectively. It was found that the action range of different forms of ground fissures to improve the erodibility of surrounding soil was basically within 155 cm. Combined with the comparative analysis of the significance of the difference, the "flat opening", "step type" and the key action range of "combined" mining ground fissures to improve the erodibility of surrounding soil was within 40, 60 and 100 cm, which can be used as an accurate prevention and control target for the effect of water and soil loss under the small spatial scale of mining ground fissures in Northern Shaanxi mining area. The results can guide the precise prevention and control of soil and water loss in the coal mining area of Northern Shaanxi and even the middle reaches of the Yellow River Basin.

     

/

返回文章
返回