ISWC OpenIR  > 水保所知识产出(1956---)
降雨侵蚀过程中黑土团聚体流失特征
卢嘉1; 郑粉莉1,2; 安娟3; 李桂芳2,4
2016
Source Publication生态学报
Volume36Issue:8Pages:2264-2273
Abstract

坡面侵蚀过程中土壤团聚体流失可直接反映土壤团聚体的破碎程度以及雨滴打击和径流搬运之间的相互作用。基于模
拟降雨试验,研究降雨侵蚀过程中黑土坡面土壤团聚体流失特征。试验处理包括黑土区常见的2 个侵蚀性降雨( 50、100mm/h
降雨强度) 和2 个坡度( 5°和7.5°) 以及2 种地面处理( 裸露休闲和秸秆覆盖) 。结果表明: 裸露休闲处理下径流含沙量是秸秆
覆盖处理的27.5—141.3 倍,且不同处理下含沙量最大值均出现在降雨初期。覆盖秸秆与无覆盖试验处理下土壤团聚体流失均
以<0.25 mm 微团聚体为主。秸秆覆盖试验处理下泥沙中<0.25 mm 微团聚体流失量占团聚体流失总量的34.5%—56.8%,而在
裸露休闲处理下其值达到82%以上。秸秆覆盖处理下的各粒级团聚体流失量较裸露休闲试验处理减少了33.3%以上,其中差
异最明显的是≥1 mm 粒级团聚体与<0.25 mm 微团聚体,二者分别较裸露休闲处理减少了43.1%—96.4%和99.0%以上。秸秆
覆盖处理下的0.25—2 mm 粒级团聚体流失比例较裸露休闲处理明显增加。秸秆覆盖试验处理下流失团聚体的平均重量直径
( MWD) 和几何平均直径( GMD) 分别是裸露休闲处理的1.5—2.9 和1.7—2.0 倍; 而秸秆覆盖处理下的平均重量比表面积
( MWSSA) 和分形维数( D) 较裸露休闲处理分别减少了26.2%—32.9%和5.1%—6.7%。

Other Abstract

Soil aggregate loss during hillslope erosion processes directly reflects the interaction among the degree of soil
aggregate breakdown,raindrop impact and runoff transportation. Different soil aggregate breakdown mechanisms result in the
size distribution of soil aggregate is different. Furthermore,soil aggregate loss has an important influence on hillslope soil
loss. However,existing studies have mostly focused on aggregate stability. Rainfall simulation experiments were conducted to
investigate Mollisol aggregate loss during rainfall erosion processes. The experimental treatments included two rainfall
intensities ( 50 mm/h and 100 mm/h) ,representative of erosive rainfalls in the black soil region of northeast China; twocommon slope gradients ( 5° and 7.5°) ; and two surface conditions ( bare land and straw mulch cover) . Each experimental
treatment had two replications. The tested soil was the Mollisol,which was collected from the upper 20 cm of the plow layer
in a maize field in Yushu City,Jilin Province,which is typical of the black soil of the region of northeast China. This study
was conducted in the rainfall simulation laboratory of the State Key Laboratory of Soil Erosion and Dryland Farming on the
Loess Plateau,Yangling City,China. A rainfall simulator system with a side-sprinkler was used to apply rainfall. The soil
pan was 8 m long,1.5 m wide and 0.6 m deep. During the rainfall simulations,runoff samples were collected in 15-L
buckets. Half of each runoff sample was immediately processed through a set of sieves with apertures of 5 mm,2 mm,1
mm,0.5 mm,and 0.25 mm. After sieving,the lost aggregate samples and the remaining half of each runoff samples were
oven-dried to calculate the soil and aggregate losses. The results showed that sediment concentration in the bare land
treatments was 27.5—141.3 times greater than that in the straw mulch cover treatments. The maximum values for sediment
concentration were observed at the beginning of the rainfall simulation,in all treatments. This indicated that the dominant
Mollisol aggregate breakdown mechanisms were slaking and mechanical breakdown,and that the effect of slaking was mainly
exerted in the initial stages of rainfall. The <0.25 mm micro-aggregates were the main aggregate size fraction lost in both the
bare land and the straw mulch cover treatments. The <0.25 mm micro-aggregate loss comprised 34.5—56.8% of the total
aggregate loss in the straw mulch cover treatments,whereas the loss was >82% in the bare land treatments. Compared with
the bare land treatments,the loss of every size aggregate decreased >33.3% in the straw mulch cover treatments; thus,the
most significant differences in soil aggregate loss were observed in the ≥1 mm and <0.25 mm size fractions between the
bare land and the straw mulch cover treatments. Compared with the bare land treatments,the loss of the ≥1 mm size
fraction and the <0.25 mm micro-aggregates decreased 43.1%—96.4% and 99.0%,respectively,in the straw mulch cover
treatments. The proportion of 0.25—2 mm aggregates in the sediment from the straw mulch cover treatments increased and
was greater than that of the bare land treatments. These results indicated that raindrop impact was the main driving force for
aggregate breakdown. The straw mulch cover eliminated the effect of raindrop impact on soil aggregate breakdown,and also
decreased runoff transport capacity. The mean weight diameter ( MWD) and geometric mean diameter ( GMD) of aggregates
in the sediments for the straw mulch cover treatments were 1.5—2.9 and 1.7—2.0 times greater than those for the bare land
treatments. Compared with the bare land treatments,the mean weight soil specific ( MWSSA) and fraction dimension ( D)
decreased 26. 2%—32. 9% and 5. 1%—6. 7%, respectively. The above four indicators reflect the aggregate loss
characteristics of Mollisols.

Keyword模拟降雨 降雨侵蚀过程 团聚体流失 黑土区
Indexed By中文核心期刊要目总览
Language中文
Document Type期刊论文
Identifierhttp://ir.iswc.ac.cn/handle/361005/8641
Collection水保所知识产出(1956---)
Affiliation1.西北农林科技大学水土保持研究所,黄土高原土壤侵蚀与旱地农业国家重点实验室
2.中国科学院水利部水土保持研究所
3.临沂大学水土保持与环境保育研究所
4.中国科学院大学
Recommended Citation
GB/T 7714
卢嘉,郑粉莉,安娟,等. 降雨侵蚀过程中黑土团聚体流失特征[J]. 生态学报,2016,36(8):2264-2273.
APA 卢嘉,郑粉莉,安娟,&李桂芳.(2016).降雨侵蚀过程中黑土团聚体流失特征.生态学报,36(8),2264-2273.
MLA 卢嘉,et al."降雨侵蚀过程中黑土团聚体流失特征".生态学报 36.8(2016):2264-2273.
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