| 引用本文: | 王健,宋鹏帅,赵宇,等.降雨对坡面结皮土壤水稳性团聚体的影响[J].灌溉排水学报,0,():-. |
| Wang Jian,Song Pengshuai,Zhao Yu,et al.降雨对坡面结皮土壤水稳性团聚体的影响[J].灌溉排水学报,0,():-. |
|
| |
|
|
| 本文已被：浏览 2160次 下载 0次 |
|
|
|
| 降雨对坡面结皮土壤水稳性团聚体的影响 |
|
王健,宋鹏帅,赵宇,等
|
|
陕西省咸阳市杨陵区西北农林科技大学
|
|
| 摘要: |
| 【目的】探讨降雨打击下产生的不同坡面结皮土壤水稳性团聚体分布。【方法】采用人工模拟降雨，研究在降雨打击作用下，地表结皮土壤水稳性团聚体的变化情况。受微地形影响，地表结皮性质呈现差异，以坡面不同位置的地表结皮土壤水稳性团聚体为研究对象，以底部无结皮土壤样品为对照，采用Yoder湿筛法探究不同类型结皮土壤团聚体的变化。【结果】在降雨打击作用下，以降雨时间5 min为例，不同位置的结皮1）土壤水稳性团聚体都呈现大团聚体比例较大的特点，表现为结构性结皮大团聚体占比最大，其次为过渡带、原状土，沉积性结皮最小。原状土、结构性结皮、过渡带、沉积性结皮土壤大团聚体所占比例分别为37.69%、41.95%、37.05%、28.93%。随降雨延续，结构性结皮和过渡带土壤大团聚体明显增加，沉积性结皮土壤大团聚体略有减少。2）土壤水稳性团聚体的平均当量直径和几何平均重量差异很大。原状土、结构性结皮、过渡带、沉积性结皮的平均当量直径分别为：0.15、0.19、0.17、0.12 mm；几何平均直径分别为：0.16、0.21、、0.19、0.14 mm。结构性结皮土壤水稳性团聚体的平均当量直径和几何平均直径最大，其次为过渡带、原状土，沉积性结皮最小。3）土壤水稳性团聚体分形维数D不同但差异不显著。原状土、结构性结皮、过渡带、沉积性结皮土壤水稳性团聚体分形维数D的大小分别为：2.725、2.705、2.725、2.737。沉积性结皮水稳性团聚体分形维数最大，其次为过渡带、原状土，结构性结皮最小。【结论】降雨打击作用使得土壤表层大团聚体被分散，小团聚体富集；大团聚体量越高，土壤结构越稳定，抗蚀能力越强；反之，抗蚀能力越弱。 |
| 关键词: 土壤团聚体;湿筛法;结皮;降雨历时 |
| DOI： |
| 分类号:S152.7 |
| 基金项目:国家自然科学基金(41771308和41371273)。 |
|
| Effect of Rainfall on Water Stability Aggregates of Crust Soil on Slope Surface |
|
Wang Jian1,2, Song Pengshuai1,2, Zhao Yu1,2, Ma Yuhong1,2
|
|
1.Northwest A&2.F University
|
| Abstract: |
| 【Objective】The distribution of water-stable aggregates in crust soils on different slopes caused by rainfall was studied. 【Method】Artificial rainfall simulation was used to study the change of water-stable aggregates in crust soil under the impact of rainfall. Influenced by micro-topography, surface crust properties show differences. The water-stable aggregates of surface crust soils at different locations on slopes were studied, and the soil samples without crust at the bottom were taken as controls. Study on the Change of Soil Aggregates in Different Crust Types by Yoder Wet Screening Method. 【Result】Under the impact of rainfall, taking 5 minutes of rainfall as an example, crusts at different locations 1)Soil water-stable aggregates are characterized by large aggregates proportion. Structural crust contains the largest aggregates, followed by transitional zone and undisturbed soil, and sedimentary crust is the smallest. The proportion of macroaggregates in undisturbed soil, structural crust, transitional zone and sedimentary crust were 37.69%, 41.95%, 37.05% and 28.93% respectively. With the continuation of rainfall, soil macroaggregates in structural crusts and transitional zones increased significantly, while those in sedimentary crusts decreased slightly. 2) Average equivalent diameter and geometric average diameter of soil water-stable aggregates vary greatly. The average equivalent diameters of undisturbed soil, structural crust, transitional zone and sedimentary crust are 0.15, 0.19, 0.17 and 0.12 mm, respectively. The geometric average diameters are 0.16, 0.21, 0.19 and 0.14 mm, respectively. The average equivalent diameter and geometric average diameter of water-stable aggregates in structured crust soil are the largest, followed by transition zone and undisturbed soil, and sedimentary crust is the smallest. 3) The fractal dimension D of soil water-stable aggregates is different, but the difference is not significant. The fractal dimensions D of water-stable aggregates in undisturbed soil, structural crust, transitional zone and sedimentary crust are 2.725, 2.705, 2.725 and 2.737, respectively. The fractal dimension of water-stable aggregates in sedimentary crusts is the largest, followed by transitional zone and undisturbed soil, and structural crusts are the smallest. 【Conclusion】 Rainfall strikes disperse large aggregates and enrich small aggregates in the soil surface. The higher the content of macroaggregates, the more stable the soil structure, the stronger the anti-erosion ability; on the contrary, the weaker the anti-erosion ability. |
| Key words: Soil aggregates; Wet screening method; Crust; Rainfall duration |
|
|
|
|
