| 摘要: |
| 【目的】研究春季解冻期的冻融作用对海州露天煤矿排土场不同复垦植被类型土体饱和导水率的影响。【方法】以不同复垦植被类型0~20 cm土层土壤为研究对象，通过恒温试验箱模拟春季解冻期自然环境，采用特制环刀入渗仪进行入渗试验，分析不同复垦植被类型0~20 cm土层的土壤在不同冻融循环次数、解冻时间及冻融作用前后土体饱和导水率的变化特征。【结果】冻融循环过程中，饱和导水率在冻融循环次数、解冻时间、复垦植被类型及其交互作用的共同影响下呈降低趋势，饱和导水率由高到低为荒草地＞火炬树林地＞榆树林地＞耕地。冻融作用前后，各复垦植被类型土壤物理性质均发生变化，榆树林地、火炬树林地、耕地、荒草地土壤体积质量的增量分别为0.05、0.07、0.05、0.02 g/cm3，孔隙度分别降低0.47%、1.51%、1.34%、0.64%，饱和导水率分别降低0.8、0.49、0.2、0.19 mm/min。冻融作用后，土体饱和导水率由高到低为榆树林地＞火炬树林地＞耕地＞荒草地。【结论】冻融作用后，各复垦植被类型土体饱和导水率呈下降趋势，表现为榆树林地＞火炬树林地＞耕地＞荒草地，荒草地对冻融作用具有较强的缓冲能力。 |
| 关键词: 矿山生态修复；复垦模式；饱和导水率；冻融循环；解冻时间 |
| DOI：10.13522/j.cnki.ggps.2024207 |
| 分类号: |
| 基金项目: |
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| Effects of freeze-thaw cycles on saturated hydraulic conductivity of soils reclaimed with different vegetation types at an open-pit coal mine dumping site |
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XIONG Shuzhen, LYU Gang
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Liaoning Technical University, Fuxin 123000, China
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| Abstract: |
| 【Objective】Freeze-thaw cycles are a critical abiotic process that reshape soil structure. This study investigates their impact on the saturated hydraulic conductivity of soil in an open-pit coal mine in Haizhou, which is reclaimed with different vegetation types. 【Method】A laboratory experiment was conducted in spring. The vegetation types studied included Ulmus pumila forestland, Rhus typhina forestland, farmland, and waste grassland. Soil samples from the top 0-20 cm soil layer was used in the experiment. The natural spring thaw environment was simulated using a constant temperature test chamber. Infiltration tests were performed with a ring infiltrometer. The saturated hydraulic conductivity was analyzed under different freeze-thaw cycles, thawing times, and before and after freeze-thaw treatments.【Result】① The saturated hydraulic conductivity decreased with increasing freeze-thaw cycles and thawing time. It also varied with vegetation type and their interactions. The saturated hydraulic conductivity measured under different vegetation types was ranked in the order of waste grassland＞Rhus typhina forestland＞Ulmus pumila forestland＞farmland. ② Soil physical properties before and after freeze-thaw cycles differed between vegetation types. The freeze-thaw cycles increased soil bulk density by 0.05, 0.07, 0.05, and 0.02 g/cm3 for Ulmus pumila forestland, Rhus typhina forestland, farmland, and waste grassland, respectively, and reduced the saturated hydraulic conductivity by 0.8, 0.49, 0.2, and 0.19 mm/min, respectively. ③ After freeze-thaw cycles, the saturated soil hydraulic conductivity was ranked in order of Ulmus pumila forestland＞Rhus typhina forestland＞farmland＞waste grassland.【Conclusion】Freeze-thaw cycles reduced saturated hydraulic conductivity for vegetation types, and its value was ranked in the order of Ulmus pumila forestland＞Rhus typhina forestland＞farmland＞waste grassland. Our results showed that the waste grassland was most resistant to freeze-thaw effects. |
| Key words: ecological restoration of mines; reclamation mode; saturated hydraulic conductivity; freeze thaw cycle; thawing time |
