摘要
坝地沉积泥沙记录了坝控小流域内土壤侵蚀特征及侵蚀环境演变的相关信息,是研究流域土壤侵蚀的重要媒介。研究通过在淤地坝内洪水冲开的一个11.66m的垂直剖面上按沉积旋回自下而上分层取样,分析沉积泥沙不同组分百分含量、特征粒径的剖面变化规律。结果表明：1）淤地坝内沉积泥沙主要以粗粉粒（0.01~0.05mm）为主,其平均含量为53.61%,且变异系数最小;2）个别层次出现粗砂（0.25~1mm）,粗颗粒泥沙的出现对流域内大暴雨有一定的指示作用;3）沉积剖面的0~67cm为累积耕作层,该层的出现具有一定的时标意义;4）淤地坝沉积剖面存在粒径变异的转折点（600cm）,该点可用来衡量水沙动力条件和沟道比降对泥沙粒径分布所起的作用。
The sediment is an important medium for retrieval of the soil erosion characteristics, which indi- cates the important information about the environmental processes in relation to soil erosion and deposition. We analyzed the variation of the different components, percentages and the characteristics of particle sizes, which were sampled from a 11.66 m depth soil profile in the typical check dam on the Loess Plateau. The re- sult showed that： 1）the deposition sediment mainly contains coarse silt（0. 25~1 mm） with the average con- tent of 53.61%, and the coefficient of variation was minimums 2） sand（0.25~1 mm） was found only in a few layers, indicating the heavy rain in watersheds 3） there was an accumulated cultivated layer at the depth of 0--67 cm in the profile, which had indicative role for special times 4） there was a turning point（600 cm） in the profile, which can be used to measure the effect of the water and sediment conditions ent, and had an indicative role for the sediment erosion environment of check dam.
出处
《水土保持研究》
CSCD
北大核心
2015年第2期17-21,共5页
Research of Soil and Water Conservation
基金
水利部公益性行业科研专项经费项目(201201084)
水利部黄土高原水土流失过程与控制重点实验室开放基金(201202)
中国科学院重点部署项目(KZZD-EW-04-03)
西北农林科技大学基本科研业务费专项经费项目(QN2011146)
关键词
土壤侵蚀
沉积旋回
粒径
黄土高原
淤地坝
soil erosion
cycle of sedimentation
particle size
check dam
Loess Plateau~
