Infiltration and Runoff Yield Characteristics in Jiangjia Ravine
详细信息
- 责任者：Guo Xiaojun (Key Laboratory of Mountain Hazards and Land Surface Progress ; Institute of Mountain Hazards and Environment ; CAS ; Chengdu 610041 ; China) ; Cui Peng
- 刊名：Journal of Mountain Research
- 出版年：2012
- 卷期：30(5)
- 关键词：泥石流 ; debris flows ; 渗流 ; seepage flows ; 云南 ; Yunnan Province
- 页码：p.585-591
- 图表：3 illus., 3 tables, 11 refs.
- 分类号：1702
- issnNo：ISSN1008-2786
- isbnNo：CN51-1516/P
摘要
Infiltration characteristics were obtained by outdoors experiments on various typical points in debris flow source region in Jiangjia Valley.Some basic characteristics were presented,including 1) The infiltration capacity curve can be preferably fitted by Horton formula.2) The infiltration intensity in this area is relatively hard.Saturated stable infiltration rates in all kinds of land use types in Red-Yellow soil which is the main soil type in this area are bigger than 0.08 mm/s.3) To the three soil types,infiltration coefficient form great to small: gravelly soil → Red-Yellow soil → Dry Red soil;to different land use types in Red-Yellow soil,the sequence is: plowland → woodland → shrubbery →bare land(landslide back wall)→ grassland.The interflow in this area plays an important role in the runoff because of the big infiltration capacity.An isotope separating interflow runoff during the artificial rainfall experiment was carried out in one plot.The samples of antecedent soil moisture,rainfall and interflow were collected,measured and analyzed.During the rainfall,infiltration increased the soil water content which made pressure to push the antecedent soil moisture migrate downward.So,it was possible that the antecedent soil moisture peak at the wetting front during the infiltration.Therefore,in the early stage of the runoff,the antecedent accounted for a very large proportion(86.46%).As the time last,rainfall water gradually took the place of the antecedent soil moisture to be main part of water in the soil,meanwhile,the proportion of rainfall water in the underground water was also gradually increasing(85.63% in the end of the experiment).It was deduced that during a short duration rainstorm,over-infiltrating runoff dominated and slope debris flow is easily to occur;during a long-time drizzle,stored-full runoff dominated the antecedent soil water plays an non-negligible role meanwhile,slump debris flow and landslide debris flow are easier to occur instead.This paper contributes the runoff producing and debris flow starting mechanism in this area.