干湿交替作用对西南地区黄壤团聚体稳定性的影响

发布时间：2019-03-24 13:51

【摘要】：为了探究我国西南地区干湿交替作用对土壤团聚体稳定性的影响,选取重庆缙云山典型黄壤为研究对象,在4个前期含水率(风干,10%,15%,20%)水平下,对4组不同粒级团聚体(1~2,2~3,3~5,5~7mm)分别进行7个不同干湿交替过程(1,2,3,5,7,10,15次)模拟。采用Le Bissonnais法,对干湿交替作用后的团聚体在不同破碎机制下的稳定性特征进行了探讨。结果表明:(1)快速湿润(FW)对团聚体稳定性的破坏程度最大,且与机械扰动(ST)和慢速湿润(SW)存在显著差异;(2)小粒径团聚体相较于大粒径团聚体稳定性更高;(3)干湿交替过程对团聚体存在明显的破坏作用,且在不同含水率变化范围下其破坏程度不同;(4)干湿交替作用主要通过影响团聚体破碎后2mm团聚体的百分比含量来影响团聚体的稳定性。该结果对于研究西南地区土壤侵蚀的发生机理具有一定的参考价值。
[Abstract]:In order to investigate the effect of dry-wet alternation on the stability of soil aggregates in southwest China, the typical yellow soil in Jinyun Mountain, Chongqing, was selected as the research object under four levels of water content (air-dried, 10%, 15%, 20%). Seven different dry-wet alternating processes (1, 2, 3, 5, 7, 10, 15 times) were simulated for 4 groups of different size aggregates (1 ~ 2, 2 ~ 3, 3 ~ 5, 5 ~ 7 mm). Le Bissonnais method was used to study the stability characteristics of the aggregates under different crushing mechanisms after alternation of dry and wet conditions. The results showed that: (1) Rapid wetting (FW) had the greatest damage to the stability of aggregates, and there was significant difference between rapid wetting (SW) and mechanical disturbance (ST) and slow wetting (SW); (2) the stability of small-diameter aggregates is higher than that of large-diameter aggregates, (3) the dry-wet alternation process has obvious damage effect on the aggregates, and the degree of destruction is different in different water content range. (4) the effect of dry-wet alternation mainly affected the stability of 2mm aggregates by affecting the percentage of aggregates after fragmentation. The results have certain reference value for studying the occurrence mechanism of soil erosion in southwest China.
【作者单位】：北京林业大学水土保持学院;北京市水土保持工程技术研究中心(北京林业大学);
【基金】：国家“十三五”科技支撑计划子课题“三峡库区城郊防护林结构调控与高效经营技术”(2015BAD07B040304)
【分类号】：S157.1

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