摘要
[目的]对比分析不同坡度条件下黑土坡面细沟宽度、深度、宽深比、细沟剖面形态及沟壁坡度特征,为东北黑土区坡耕地细沟侵蚀防治提供科学参考。[方法]在野外径流小区不同坡度(5°和10°)下开展汇流冲刷试验[1 L/(min·m^2),历时60 min]。[结果](1)试验条件下,黑土坡面细沟剖面形态主要为"U"型,细沟平均宽深比介于2.3~4.9之间;(2)随着坡度的增大,细沟下切侵蚀作用增强幅度明显超过细沟沟壁崩塌侵蚀作用,导致细沟宽深比减小,细沟剖面形态由"宽浅型"向"窄深型"转化;(3)对于坡面不同位置,细沟平均宽深比在坡上,坡中,坡下位置分别为2.7,1.6,5.4,即自坡面上部到下部依次表现为"宽浅型"—"窄深型"—"宽浅型"的细沟剖面变化特征;(4)黑土坡面细沟沟壁坡度主要为37.7°~85.2°,其值随着地面坡度的增加而增大,且不同坡位之间细沟沟壁坡度表现为坡中位置大于坡上和坡下位置。[结论]防治东北黑土区陡坡耕地中段位置的细沟发育尤为重要,对缓解该区水土流失问题有重要作用。
[Objective]The characteristics of the widths,depths,width-depth ratios,profiles,and wall gradients of rills on a mollisol hillslope were analyzed to provide a scientific reference for controlling rill erosion on slope croplands in the Chinese mollisol region.[Methods]Inflow scour experiments with a 1 L/(min·m^2)inflow rate were conducted over 60 min under different typical slope gradients(5°and 10°)in natural runoff plots.[Results]①The rill profiles of the mollisol hill slope were mainly“U”shaped and the mean rill width-depth ratios ranged from 2.3 to 4.9.②As the slope gradient increased,the undercut erosion of the rills exceeded that of the collapse erosion of the side-walls,which induced a decrease in the rill width-depth ratio and a variation in the rill profiles from a“wide and shallow type”to a“deep and narrow type”.③The mean rill width-depth ratios of the upper,middle,and lower hillslope positions were 2.7,1.6,and 5.4,respectively.This reveals that the rill profile characteristics transformed from the“wide and shallow type”to the“deep and narrow type”,and then to the“wide and shallow type”from the upper hillslope to the lower hillslope.④The rill wall gradients of the mollisol hillslope mainly ranged from 37.7°to 85.2°,and increased with an increase in the slope gradient.The rill wall gradients of the middle hillslope were greater than those of the upper and lower hillslopes.[Conclusion]It is much more important to control rill development in the middle parts of relatively steep hillslopes than other parts;this is beneficial for alleviating rill erosion in the mollisol region of China.
作者
车晓翠
赵文婷
沈海鸥
牟廷森
Che Xiaocui;Zhao Wenting;Shen Haiou;Mou Tingsen(College of Resources and Environment,Jilin Agricultural University,Changchun,Jilin 130118,China)
出处
《水土保持通报》
CSCD
北大核心
2020年第5期55-59,共5页
Bulletin of Soil and Water Conservation
基金
国家重点研发计划项目“黑土侵蚀防治机理与调控技术”(2016YFE0202900)
国家自然科学基金项目“黑土区坡耕地侵蚀沟发育及其形态特征研究”(41601281)。
关键词
细沟剖面
汇流冲刷
沟壁坡度
坡度
黑土
rill profile
inflow scour
rill wall gradient
slope gradient
mollisol
