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1IntroductionDebrisflowsaregeneralydescribedasgravityflowsofamixtureofsoil,rocks,waterandair.Initiationofdebrisflowsrequiresl... 相似文献
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IINTRODUCTIONDebrisflowisaphenomenonhappeninginextremeseveresit'Uationofsoilerosion(Guan,1996).ItoccursfrequentlyanddistributesdenselyinupperreachesoftheYangtzeRiverandtransportsahugeamountofsedimentilltotheriver.Debrisflowdepositinfluencesthecompositionofsedimentandthemorphologyoftheriverbedfromupstreamt6downstreamandthenaffectsthedynamiccharactersandsedimentbudgetoftheYangtzeRiver.Furthermore,itimpactsonthefloodandwaterconservancyengineering.2DEBRISFLOWGULLY--HIGHWAYOFSEDI… 相似文献
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I.I~rnoxTherearemanyproblemsfortheresearchondebrisflowmechanism.ThemostimPOrtantandmOSturgentoneisthecalculationofresistanceandvelocityOfdebrisflow.Inthisaspectmuchresearchhasbeencompletedfromtwoapproaches.Oneapproachisbasedonordinaryhydraulicsandmodifiedbyfieldobservationdata,andempiricalformulaeofdebrisflowresistanceandvelocitywereestablished.MOStoftheearlyresearch,suchascalculatingdebrisflowvelocitywiththemodifiedformOfMariningformula,belongedtothisscope.Theonlydifferenceisthattherough… 相似文献
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Wang Guangqian 《国际泥沙研究》1994,(3)
ANALYSISONTHEDEBRISFLOWSURGES¥WangGuangqian(Professor,Dept.ofHydraulicEngineering,TsinghuaUniversity)Abstract:Basedonthefunda... 相似文献
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1.INTRODUCTIONDebrisflowisadistincttypeofmassmovementcommonlytriggeredbyintenserainfallandmeltingsnowonsteephillslopes.Althoughgreateffortshavebeenmadeinthestudyofthemechanismofthemotion,considerableambiguitypersistsconcerningtheinitiationandmotionofdebrisflow.Debrisflowcanbeinitiatedinsteepslopebecauseofthehighgravitationalforceandcanalsobetriggeredbyheavyrainstormongentleslopebyhighscouringcapacityofthetorrentialflood.Debrisflowisturbulentbecauseofitshighflowvelocityinsomecircumstancesa… 相似文献
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1 INTRODUTIONTaiwan is a hilly-mountainous island lying across the center of the tropic. The slopeland accounts fortwo thirds of the total area of Taiwan. Most mountains are consisted of geologically young rocks incategories of fissile slates and shales which are easily eroded by weather. TOrrents combined with fissileslates and shales form debris flows with a very strong destrUctive power. This kind of debris flow canpotentially occur for almost all torrents whose gradient is steeper th… 相似文献
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Zili FENG Peng CUI Xiaoqing CHEN Jie CHEN 《国际泥沙研究》2006,21(4):294-311
1 INTRODUCTION In the watershed of the Jiangjia Ravine, the frequency of occurrence of rainstorms which can mobilize debris flows is high, and there are abundant unconsolidated materials deposited in the upstream area, these resulted in frequent eruption … 相似文献
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1INTRODUCTIONSedimentdepositionisoneofthemajorcausesofflood.ThelollgtermallllualtransportofsedimentrecordedattheYichangHydrologicalStationis530Mt,ofwhich256Mt(accountingfor48.8%ofthetotal)isfromtheJinshaRiverand140Mt(26.6%)fromtheJialingRiver.The783-kmstretchoftilelowerJillshaRiverfromDukoutoYichangisthekeyareaofsedimentyield,andsupplies83.5%ofthetotalsedimentintheriverbasin(Guo,1998).Intheotherwords,sedimentloadinthelowerJinshaRiverconstitutesabout40%ofthatilltileupperYangtzeRiver… 相似文献
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YU Bin Associate Professor Institute of Mountain Hazards Environment Chinese Academy of Science P. O. BOX . Chengdu. PR China. 《国际泥沙研究》1997,(3)
LINTRODUCTIONThedebrisflowisaverycomplexflow.Itdiffersfromwaterflowandsuspendedflowinmovingandstagnation.Thedebrisflowisgenerallydiscribedasthegravityflowofsoil.rock,waterandinitiatedbylandslide,usuallyduetohighrunoffflow.Theoccurrenceofdebrisflowisratherunpredictableandverydestwhve.Debrisflowcouldmovefasterthanthemorecommonlandslideandtendto~tareasatmuchgreaterdistancefromthesourceofhazard.Debrisflowdisastershavebeenrecognizedasacriticalproblemfacingtheworldtodayandincreasingattentionha… 相似文献
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PANG Bingdong Assoc. Prof Dept. Of Basic Sciences Beijing Insitute of Meteorology Beijing China 《国际泥沙研究》1997,(3)
LINTRODUCTIONDisastersofdebrisflotvoccurfrequentlyinChina.Mostofthemareinrainstormtype.TherainStormdebrisflowiscausedbyStormrainfallthatinducesastrongStreamflowsonloosematerialsinwatershed.Theeffectsofprecipitationonthedebrisflowareasfollows(ChengduResearchInstituteC;DisasterandEnvironment,1989)f(l)Precipitationacceleratesthematerialsofloosedebristogather,(2)PrecipitationsuPPlywatercomponentofdebrisflow,(3)Precipitationprovidesdynamicconditionsfordebrisflow,(4)Precipitationisatrigg… 相似文献
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GAO Yitang Engineer Soil Water Conservation Bureau Yellow River Conservancy Commission Zhengzhou P.R.China. QI Pu Senior Engineer Institute of Hydraulic Research Yellow River Conservancy Commission Zhengzhou P. R. China 《国际泥沙研究》1997,(3)
Debrisflow,definedasakindofhighlycondensedtit!o-phaseflowofsolidandfluid,iscomposedofslurryandrocksofdifferentsizeswithageneraldensity'ofI.2to2.3t/m3.Theactivityliesbetweenfloodandlandslide.Itflowslikenormalfloodandsholvsturbulentstateaswithlesssolidcontentsandlowerviscosity,itisplasticviscousflowwithunstablegUstmovementwhellitisofhighsolidcontainsandhighviscosity.Debrisflowisformedunderthreebasicconditionsfprecipitousslopeoflandform,solidwasteoflargevolume,andenoughwatersupply.Theoccurrence,… 相似文献
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H. M. BLIJENBERG P. J. DE GRAAF M. R. HENDRIKS J. F. DE RUITER A. A. A. VAN TETERING 《水文研究》1996,10(11):1527-1543
Rainfall was simulated on unconfined plots on regolith in debris flow source areas using a portable simulator. In total, 351 simulations were carried out on steep slopes (27–54°) with rainfall intensities of 28–291 mm/h. From these rainfall simulations the infiltration parameters sorptivity (S) and steady-state infiltration capacity (K) of the regolith, and a threshold for the occurrence of micro-scale mass movements, were obtained. Two evaluation methods were used to obtain the infiltration parameters K and S. The ‘infiltration envelope’ method uses rainfall intensity and time to ponding from multiple tests and fits an infiltration envelope through the data from which K and S can be obtained. The ‘constant runoff’ method uses rainfall intensity and overland flow intensity to calculate K, after which S can be calculated in several ways by using time to ponding. The constant runoff method produced K values of 16.6–128 mm/h, which usually show a log-normal distribution. K values depend on the regolith parent material and rainfall intensity. Using this method, S values are 0.088–0.381 cm/min1/2. The infiltration envelope method produced K values of 9.8–131 mm/h and S values of 0.14–0.32 cm/min1/2. It can be argued that both methods overestimate K as well as S, but quantitative relations between measured/calculated and actual values of K and S have not yet been obtained. At high rainfall intensities, typically 100 mm/h or more, micro-scale mass movements sometimes occur. A lower threshold curve for the occurrence of these micro-scale mass movements has been constructed. It is a function of both slope angle and rainfall intensity. The micro-scale mass movements could play an important part in the initiation of debris flows in the study area, possibly by delivering sediment to overland flow. On the very steep slopes, the sediment-rich overland flow can easily mobilize coarse material. 相似文献
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一、引言 太阳活动区喷发出的粒子流引起太阳风对地球磁场和电离层作用,从而发生地磁暴和电离层骚扰,所以它们的发生是与太阳活动有着密切的关系。但是,在地磁暴期间常常伴随着电离层F_2层骚扰,即峰值电子密度相对于中值有大的减少或增加。 相似文献
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一、引言 太阳活动区喷发出的粒子流引起太阳风对地球磁场和电离层作用,从而发生地磁暴和电离层骚扰,所以它们的发生是与太阳活动有着密切的关系。但是,在地磁暴期间常常伴随着电离层F_2层骚扰,即峰值电子密度相对于中值有大的减少或增加。 相似文献
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1 INTRODUCTION An important goal of geomorphology is to understand the dynamics of landform evolution, and within geomorphology, the development of slopes has long been of great interest to modern and classical scholars (Gilbert, 1877; Davis, 1898; Penck, 1972; Bryan, 1940; Carson and Kirkby, 1972; Chorley et al., 1984; Abrahams et al., 1985; Selby, 1993). Accompanied with slope evolution, soil, water, and nutrients run off at the same time. All these earth surface processes have great… 相似文献
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EXPERIMENTAL STUDY ON EQUILIBRIUM CONCENTRATION OF DEBRIS FLOWS 总被引:1,自引:0,他引:1
Bin YU Assoc Prof. Chengdu Institute of Mountain Disaster Enviromnent CAS P.O. Box P. R. China.E-mail: drbinyu@sc.homeway.com.cn 《国际泥沙研究》2001,16(2)
Discussion open until 2002.EmunmL SwrY ONEQUII.thare CONCENTRATION OF DEBRIS rrOWSBin YU1AaSTsiCTThe paPe PresentS experimntal study of debris flows. The equiMm concentIation of solidparticle in the now is a hahon of the energy slope, density of solid Particle and kinetic ffichonange of paxtiles. The kinhc forhon angle is a funhon of intemal ffichon angle, the cOnCentrationof solid phocles and the mtalmum POssible concewhon. TO deteImin th6 hahon between thekinetic fficho… 相似文献