山地学报
山地學報
산지학보
JOURNAL OF MOUNTAIN SCIENCE
2015年
3期
257-267
,共11页
植被发育斜坡%滑坡%降雨入渗%根-土间隙
植被髮育斜坡%滑坡%降雨入滲%根-土間隙
식피발육사파%활파%강우입삼%근-토간극
a vegetated slope%landslide%rainfall infiltration%soil-root interstice
水分或溶液在土体中的迁移具有空间和时间上的异质性。以植被发育斜坡云南昭通头寨沟和昆明呈贡段家营为研究试验区,分别运用亚甲基蓝和罗丹明B溶液进行了多次染色示踪渗透试验,发现根-土间隙的导流现象十分明显,其导流作用很可能已经超过了传统的三类土体大孔隙。然而,国内外研究者对根-土间隙方面的研究还比较欠缺。为此,对根-土间隙宽度为0.5~3.0 mm,步长为0.5 mm流道内单相流体摩擦阻力系数和入渗速度进行了理论计算,并讨论了在同一流道和不同间隙流道内影响水分下渗速度的因素,结果表明:根-土间隙的大小对根-土间隙通道内流体的流动特性有着重要影响,随着间隙的减小摩擦阻力系数也相应减小;间隙对流动阻力系数的影响还依赖于Re 的大小,其影响随Re 的减小而减小。在昭通头寨植被发育斜坡土体中,根-土间隙宽度主要集中在0.5~1.0 mm,间隙内水分下渗的速度分布在区间0.014~0.203 mm/s;相同面积上,头寨试验区渗透速率是呈贡段家营试验区的26.28倍。由于根-土间隙的存在,大大地促进了土体水分的快速下渗,对滑坡孕育的贡献是显著的。
水分或溶液在土體中的遷移具有空間和時間上的異質性。以植被髮育斜坡雲南昭通頭寨溝和昆明呈貢段傢營為研究試驗區,分彆運用亞甲基藍和囉丹明B溶液進行瞭多次染色示蹤滲透試驗,髮現根-土間隙的導流現象十分明顯,其導流作用很可能已經超過瞭傳統的三類土體大孔隙。然而,國內外研究者對根-土間隙方麵的研究還比較欠缺。為此,對根-土間隙寬度為0.5~3.0 mm,步長為0.5 mm流道內單相流體摩抆阻力繫數和入滲速度進行瞭理論計算,併討論瞭在同一流道和不同間隙流道內影響水分下滲速度的因素,結果錶明:根-土間隙的大小對根-土間隙通道內流體的流動特性有著重要影響,隨著間隙的減小摩抆阻力繫數也相應減小;間隙對流動阻力繫數的影響還依賴于Re 的大小,其影響隨Re 的減小而減小。在昭通頭寨植被髮育斜坡土體中,根-土間隙寬度主要集中在0.5~1.0 mm,間隙內水分下滲的速度分佈在區間0.014~0.203 mm/s;相同麵積上,頭寨試驗區滲透速率是呈貢段傢營試驗區的26.28倍。由于根-土間隙的存在,大大地促進瞭土體水分的快速下滲,對滑坡孕育的貢獻是顯著的。
수분혹용액재토체중적천이구유공간화시간상적이질성。이식피발육사파운남소통두채구화곤명정공단가영위연구시험구,분별운용아갑기람화라단명B용액진행료다차염색시종삼투시험,발현근-토간극적도류현상십분명현,기도류작용흔가능이경초과료전통적삼류토체대공극。연이,국내외연구자대근-토간극방면적연구환비교흠결。위차,대근-토간극관도위0.5~3.0 mm,보장위0.5 mm류도내단상류체마찰조력계수화입삼속도진행료이론계산,병토론료재동일류도화불동간극류도내영향수분하삼속도적인소,결과표명:근-토간극적대소대근-토간극통도내류체적류동특성유착중요영향,수착간극적감소마찰조력계수야상응감소;간극대류동조력계수적영향환의뢰우Re 적대소,기영향수Re 적감소이감소。재소통두채식피발육사파토체중,근-토간극관도주요집중재0.5~1.0 mm,간극내수분하삼적속도분포재구간0.014~0.203 mm/s;상동면적상,두채시험구삼투속솔시정공단가영시험구적26.28배。유우근-토간극적존재,대대지촉진료토체수분적쾌속하삼,대활파잉육적공헌시현저적。
The moisture or solution migration in soil with heterogeneity in space and time. This paper based on the distribution and vegetation development test area of Touzhai Gully( in Zhaotong of Yunnan,China)and Duanjiaying ( in Cheng’gong of Yunnan,China)as the research background,In the experimental area,respectively using methyl-ene blue and rhodamine B solution dyed tracer penetrant test many times and found that the diversion phenomenon is very obvious,the diversion function is likely more important than the traditional three kinds of soil macropore, however,the research of soil-root interstice is relatively lacking at home and abroad. The theoretical calculation was performed to predict the speed of the fluid and the flow characteristics for the developed flow in soil-root interstice with the gap size of 0. 5~3. 0 mm,the step length is 0. 5 mm. The calculation results are in good agreement with experimental data. In addition,the gap size of the soil-root interstice has great impact upon the flow characteristics. The decrease of the gap size reduces the friction factor,and discussed the influence factors of water infiltration in the same channel and different interstice width . The results show that the higher the Reynolds number,the larger the effect of the gap size upon the friction coefficient during single-phase flowing through the soil-root interstice;the effect of the gap size upon the friction coefficient depends on the Reynolds number,and will decrease with the de-crease of the Reynolds number. The soil-root interstice width of vegetation development in soil slope are mainly con-centrated in 0. 5~1. 0 mm in Touzhai,the speed of water infiltration is the range of 0. 014~0. 014 mm/s. On the same area,the infiltration rate of Touzhai Gully test area is 26. 28 times to Duanjiaying test area. The existence of soil-root interstice,greatly promoted the rapid infiltration of the soil moisture,the results show that the contribution of soil-root interstice macropore to the landslide preparation is notable.