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黄土坡面细沟侵蚀过程的REE示踪 总被引:6,自引:0,他引:6
利用REE示踪技术探讨了坡面细沟侵蚀的发育过程。试验结果表明:在细沟发育过程中,各坡段细沟侵蚀量呈动态变化趋势;细沟发育过程可以分为起始、发展、稳定3个阶段,在不同阶段,侵蚀方式、发育特征迥异。总的看来,在坡顶部、上部、中部、下部4个坡段上,细沟发育过程中,坡面下部的侵蚀量较大。但随着放水流量的增加,坡面上部侵蚀量的比重增加。由于溯源侵蚀,最下部坡段的相对侵蚀量从92%减少到37%,呈显著下降趋势,其它3个坡段则分别从4.7%、0.25%、2.14%增加到29%、17%和23%。试验结果还表明,REE示踪法不仅可定量测定不同坡位的侵蚀量,还可以揭示冲刷过程中各坡位相对侵蚀量的变化趋势。 相似文献
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坡面草被覆盖对坡沟侵蚀产沙过程的影响 总被引:13,自引:0,他引:13
By scouring experiments, the changeable process and characteristics of sediment yield in the hillslope-gully side erosion
system with different coverage degrees and spatial locations of grass were studied. Five grass coverage degrees of 0, 30%,
50%, 70%, 90%, three spatial locations of grass (upslope, mid-slope, low-slope) and two water inflow rates of 3.2 L/min, 5.2
L/min were applied to a 0.5 by 7 m soil bed in scouring experiments. Results showed that the sediment yield decreased with
the increase of grass coverage degree at 3.2 L/min water inflow rate in scouring experiments and the sediment yield with different
grass locations on the sloping surface was in the order of upper > middle > lower. At 5.2 L/min water inflow rate, the differences
of sediment yield among various grass coverage degrees were increased, whereas the changeable tendency of sediment yield with
different grass locations on the whole sloping surface was not very obvious. The proportion of sediment yield from the gully
side increased in an exponential relationship with the increase of grass coverage degree. When the grass was located on the
lower position of hillslope, the influence for accelerating gully erosion is the greatest.
Foundation: National Basic Research Program of China, No.2007CB407201; National Key Technology R&D Program, No.2006BAB06B01-06; Science
and Technique Development Foundation of YRIHR, No.200603
Author: Li Mian (1968–), Ph.D and Senior Engineer, specialized in soil erosion. 相似文献
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不同坡面植被空间布局对坡沟系统产流产沙影响的实验 总被引:5,自引:0,他引:5
植被在有效控制水土流失、改善生态环境中具有重要作用。为探讨坡面不同植被覆盖度、不同植被空间布局对坡沟系统侵蚀产沙的影响,以4 m长坡面(坡度为20°)和3 m长沟坡(坡度为50°)组成的坡沟系统为研究对象,采用不同放水流量(3.2 L/min、5.2 L/min)的放水冲刷实验,研究了不同放水流量、不同植被覆盖度、不同植被布设部位对坡-沟系统及沟坡侵蚀产沙的影响。结果表明,在实验条件下,不同植被布设部位在相同放水流量、相同植被覆盖度条件下对坡沟系统侵蚀产沙有明显影响,而对产流量无明显影响;沟坡部分侵蚀产沙量不随坡面植被覆盖度的增大而减小,相反呈增大趋势。说明在实验条件下,对坡沟系统而言,仅在坡面部分布设植被,尽管能在一定程度上减少坡沟系统侵蚀产沙,但并不能有效减小沟坡部分的侵蚀产沙,甚至引起沟坡部分侵蚀产沙的增大。因此,水土流失治理过程中采取有效措施进行坡沟兼治将是减少水土流失的有效手段。 相似文献
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坡面草被覆盖对坡沟侵蚀产沙过程的影响 总被引:11,自引:0,他引:11
通过室内放水冲刷试验方法,研究了坡沟系统坡面不同草被覆盖度及空间配置下,坡沟系统侵蚀产沙变化过程及特征。结果表明,放水流量较小时,覆盖度越高,侵蚀产沙量越小;坡面草被不同空间配置下的产沙量大小依次是:坡上部 > 坡中部 > 坡下部。大流量时,不同草被覆盖度间的产沙量差异增大,不同草被空间配置下的产沙量变化规律不十分显著。沟坡产沙比随坡面草被覆盖度的增加呈指数增加,大流量比小流量下的增加幅度要大。坡面草被布设在坡下部时,其对沟坡侵蚀的危害最大。坡沟系统侵蚀产沙变化过程是增加-稳定-下降,其变化的阶段性不如单一坡面明显。 相似文献
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