冻融循环对风沙土物理性质及抗冲性的影响试验

发布时间：2018-08-14 20:22

【摘要】：为揭示冻融循环对土壤物理性质及抗冲性的影响,以内蒙古坡耕地风沙土为研究对象,控制冻融循环次数(0~10次)和土壤质量含水量(6%,9%,12%)2个因素,在室内模拟野外冻融循环和径流冲刷过程,定量分析冻融循环对土壤含水量、容重、孔隙度及土壤抗冲性的影响规律。结果表明:(1)土壤含水量随冻融循环次数增加呈缓慢增加的趋势,增加幅度为0.51%~0.87%,且高含水量土壤增幅比低含水量土壤大;(2)随冻融循环次数的增加,土壤容重和孔隙度分别呈缓慢减小和增大趋势,且变化幅度逐渐降低,最后达到基本稳定的状态,达稳定状态后的土壤容重比未冻融土壤小(0.05±0.01)g/cm~3;(3)当冻融循环次数相同时,高含水量(12%)的土壤容重比低含水量(6%)小,而孔隙度和土壤抗冲性的降低幅度与之相反;(4)冻融循环次数对风沙土抗冲系数具有显著影响,试验土样抗冲性随冻融循环次数的增加呈显著降低趋势,但是第6次冻融循环后,试验土样的含水量、容重、孔隙度及抗冲性的变化均逐渐趋于稳定。研究结果可为季节性冻融区土壤侵蚀机理研究提供参考。
[Abstract]:In order to reveal the effects of freeze-thaw cycles on soil physical properties and anti-scouring properties, two factors, freeze-thaw cycles (0-10 cycles) and soil water content (6%, 9%, 12%) were controlled in the sandy soil of Sloping Farmland in Inner Mongolia. The freeze-thaw cycles and runoff scouring processes were simulated in the laboratory, and the effects of freeze-thaw cycles on soil water content, bulk density and pore volume were quantitatively analyzed. The results showed that: (1) with the increase of freeze-thaw cycles, the soil water content increased slowly, ranging from 0.51% to 0.87%, and the increase of high water content soil was larger than that of low water content soil; (2) with the increase of freeze-thaw cycles, the soil bulk density and porosity decreased and increased slowly, respectively. The soil bulk density was smaller than that of unfrozen-thawed soil (0.05.01) g/cm~3; (3) When the freeze-thaw cycles were the same, the soil bulk density with high moisture content (12%) was smaller than that with low moisture content (6%), and the decrease of porosity and soil Anti-scourability was opposite; (4) The freeze-thaw cycles were the same. The number of freeze-thaw cycles has a significant effect on the scour resistance coefficient of aeolian sandy soils. The scour resistance of the tested soils decreases significantly with the increase of the number of freeze-thaw cycles. However, after the sixth freeze-thaw cycles, the changes of water content, bulk density, porosity and scour resistance of the tested soils gradually become stable. For reference.
【作者单位】：西北农林科技大学水土保持研究所;中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室;
【基金】：国家自然科学基金重点项目(41330858) 西北农林科技大学博士科研启动基金项目(2452015345);西北农林科技大学大学生创新训练项目(201610712035)
【分类号】：S157.1

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