Lecture Notes ni Earth Sciences detidE yb vedmoS ,ijrahcattahB Gerald .M ,namdeirF Horst .J reuabegueN dna Adolf rehcalieS 37 A. ininamrA G. iD Silvio (Eds.) laivulF sciluardyH fo niatnuoM snoigeR galreV-regnirpS London NewYork Heidelberg Berlin siraP oykoT Kong Hong anolecraB tsepaduB Editors Prof. Aronne Armanini Dept. of Civil and Environmental Engineering University of Trent 1-38050 Mesiano di Povo, Italy Prof. Giampaolo Di Silvio Institute of Hydraulics, Faculty of Engineering University of Padua Via Loredan 20, 1-35131 Padua ISBN 3-540-54491-7 Springer-Verlag Berlin Heidelberg NewYork ISBN 0-38?-54491-7 Springer-Verlag NewYork Berlin Heidelberg This work subject is to whether reserved, are rights All copyright. the whole or part of material the concerned, is specifically the rights of reprinting, re-use translation, of recitation, illustrations, broadcasting, microfilms reproduction on or Dupli- banks. data in storage and way, other any in cation of this publication or under only thereof permitted is parts the provisions of the German Copyright Law of permission and version, current its in 9, 1965, September for always must use be liable are Violations from obtained Springer-Verlag. for prosecution under the Copy- German right Law. Heidelberg Berlin © Springer-Verlag 1991 Printed ni Germany author by ready Camera Typesetting: Hemsbach/Bergstr. Beltz, binding: and Druckhaus Printing - 32/3140-543210 acid-free paper on Printed ecaferP Following the economical and social development of the local communities, mountain regions of temperate climates are increasingly becoming the site of valuable infrastructures and important urban and industrial settlements. As the catastrophic events of last years in the European Alps have clearly shown, the vulnerability of these territories has correspondingly increased, in terms of both property damage and losses of human life. Until recently, the hydraulic scientific community has paid little attention to mountain watersheds, except perhaps during the period if the hydropower de- velopment. Nevertheless attention was then focused on problems and method- ologies somewhat different from the issues of actual environmental concern. More recently, however, hydraulic engineers have joined their colleagues from forest and rural engineering, who have traditionally dealt with erosion control in mountain areas, to bring in their own methodology, already experi- enced in lowland rivers. At the same time, academic people focused an interest in some phenomena, like massive transport, which is typical of mountain envi- ronment. To bring together all these contributions and to make the state of the art of the mountain river science (oropotamology) and lechnology, an International Workshop was called at the University of Trent (Italy), on October 1989, under the sponsorship of Fluvial Hydraulic Section of the IAHR. Three main topics have been recognized as particularly relevant from the point of view of both research and professivnal people: a) Hydrodynamics of steep channels and local scale process; b) Sediment movement and sediment training, with special emphasis on massive transporl; c) Particular features of sediment transport related to non-uniform grain-size. However, as it is the case in these circumstances, the contest of several contributions often spread over more than one topic. In the following Introduc- tion to papers, the three topics were split into 11 Sections, each one devoted to a more particular aspect recurrently addressed during the discussion. The same paper, thus, may eb mentioned in different Sections of the Introduction. Trento, march 1991 the editors stnemegdelwonkcA The Organizing Committee of the Workshop and the Editors of this book era indebted to the International Advisory Board, ohw have selected the papers: Prof. Selim Yalin ( Chairman of the Fluvial Hydraulic Sec. LA.H.R.) Prof. James C.Bathurst ( University of Newcastle upon Tyne, U.K) Dr. Lianzhen Ding (I.R,T.C.E.S., Beijing, China) Dr. Martin Jaeggi (E. T. H., Switzerland) Zurich, Prof. Masanori Michiue ( University of Toltori, Japan) and to the Moderators of the Sessions of the Workshop: Prof. Matheus deI~ies, (Delft University of Technology, The Netherlands) Dr.Gerrit £ Klaassen, (Delft Hydraulics, De Voorst Laboratory, The Netherlands) Prof. James C.Bathurst (University of Newcastle upon Tyne, U.K) ohw have neeb fundamental for stimulating the discussion and for distilling the most relevant aspects in which the following Introduction saw articulated. The Workshop was organized in the framework of the activities of the Italian Groups for the Disaster Prevention (CNR-GNDCI)) and for Sediment Transport (MURST 40~). Table of Contents Introduction to the Papers A.Armanini and G.Di Silvio A Hydrodynamics of Steep Channels and Local-scale Processes. AI. Flow Resistance over a Gravel Bed: its Consequence on Initial Sediment Move- ment W. Graf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 A2. Turbulent Flow with Small Relative Submergence H.Nakagawa, T. Tsujimoto and Y.Shimizu . . . . . . . . . . . . . . . . . 33 A3. Flow Resistance and Sediment Transportation in Streams with Steep-pool Bed Morphology S.Egashira and K.Ashida . . . . . . . . . . . . . . . . . . . . . . . . 45 .4A Modification of the Transport Rate Formula for Steep Channels L.Suszka . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 A5. Continuous Simulation of Sediment Transport in the Case of Glacierized Water- shed F.Sch5berl 71 A .6 Determination of the Critical Conditions of IncipienMto tion of Bed Load in Moun- tain Rivers W.Bartnik . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 A .7 Bed-load Transport in Steep Channels T. Tsujimoto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 AS. Flume Experiments on Alternate Bars in Unsteady Flow M. Tubino . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 A9. River Bars and Non Linear Dynamics G.Seminara . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 911 B Sediment Movement in Mountain Streams: Erosion-Deposition Models; Deposition in Reser- voirs; Ordinary and Catastrophic Events; Debris Flow; Sediment Control Devices. B1. Sediment Yield and River Bed Change in Mountain Rivers T.Mizuyama . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 741 B2. A General Model for Intense Sediment Transport of Plane Bed A.Lamberti and L.Montefusco . . . . . . . . . . . . . . . . . . . . . . 361 B3. Model Investigations on the Sediment Transport of a Lower Alpine River W.Bechteler, G. Vogel and H. Vollmers . . . . . . . . . . . . . . . . . . 971 B4. Sediment Movement on the Kurobe Alluvial Fan T.Ishikawa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 591 Ytl~ B5. Simulation of Reservoir Sedimentation in Mountain Regions M.Fujita, M.Miehiue and K.Ashida . . . . . . . . . . . . . . . . . . . 209 B6. Sediment Sluicing in Mountain Reservoirs ILScheuerlein . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 BT. Review of Disastrous Torrent Flood on the Vlasina River on June 26, 1988, Includ- ing Analysis of Flood and the Obtained Results Z.Gavrilovic and Z.Matovic . . . . . . . . . . . . . . . . . . . . . . . 235 B8. Research of Fluvial Processes in Mountains: a Change of Emphasis T.Davies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 B9. Mechanics and the Existence Criteria of Various Types of Flows During Massive Sediment Transport T. Takahashi 267 BIO. Numerical Analysis of Hillslope-Channel Interaction in First Order Basins P.Ghilardi and G.Menduni . . . . . . . . . . . . . . . . . . . . . . . . 279 Bll. Modelling Short- and Long-Term Evolution of Mountain Rivers: an Application to the Torrent Mallero (Italy) G.Di Silvio and M.Peviani . . . . . . . . . . . . . . . . . . . . . . . 293 BI2. Review of Mountain River Training Procedures in Switzerland ILP. Willi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317 B13. From the Check Dam to the Development of Functional Check Dams A.Armanini, F.Dellagiacoma and L.Ferrari . . . . . . . . . . . . . . . . 331 C Non-uniformity of Sediraent: Grain Sorting; Bed Armouring; Transport of Fine-Sediment Sus- pensions. CI. Downstream Variation of Grain Size in Gravel Rivers: Abrasion Versus Selective Sorting G.Parker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 C2. Morphological Changes and Grain Sorting in Mountain Gravel-bed Streams D.Pianese and F.Rossi . . . . . . . . . . . . . . . . . . . . . . . . . 361 C3. Diversion Structure for the "Vallabres" Water Project on the Tinee River - France. Reinterpretation of 1953 Physical Model Studies in Light of Current Knowledge on Grain Sorting M.Bouvard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383 C4. Mobile Armouring of Bed Surface in Steep Slope River with Gravel and Sand Mix- ture K.Suzuki and K.Kalo . . . . . . . . . . . . . . . . . . . . . . . . . 393 C5. Experimental Analysis of Armouring Process A.Lamberti and E.Paris . . . . . . . . . . . . . . . . . . . . . . . . 405 C6. Bed Load Transport and Hyperconcentrated Flow at Steep Slopes D.Rickenmann 429 C7. Experimental Investigations on Bed-load and Suspended Transport in Mountain Streams G. Di Silvio and S.Brunelli . . . . . . . . . . . . . . . . . . . . . . . 443 C8. Variation of Bed and Transport Mean Diameters in Non-equilibrium Conditions A.Armanini . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459 List of Contributors Aronne Armanini , Department of Civil and Environmental Engineering, University of Trent, Trent, Italy Kazuo Ashida , Disaster Prevention Research Institute, Kyolo University, Gokasho, Uji, Kyoto 611, Japan Wojeieeh Bartnik , Department of Hydraulic Engineering, Academy of Agriculture, Cra- ,woc Poland Wilhelm Beehteler , Laboratory for Hydraulics and Hydraulic Structure, University of the Armed Forces, Munich, Germany Mauriee Bouvard , Institut ed M~canique ed Grenoble, Grenoble, France Stefano Brunelli , Hydraulics Institute "G.Poleni", University of Padua, Padua, Italy Tim R.H. Davies , Natural Resources Engineering Department, Lincoln College, Univer- sity of Canterbury, New Zealand Giampaolo Di Silvio , Hydraulics Institute "G.PoIeni', University of Padua, Padua, Italy Franeeseo Dellagiaeoma , Provincia Autonoma di Trento, Trent, Italy Shinji Egashlra, Disaster Prevention Research Institute, Kyoto University, Gokasho, Uji, Kyoto 611, Japan Luigi Ferrari , Provincia Autonoma id Trento, Trent, Italy Masaharu Fujita , Department of Civil Engineering, Tottori University, Tottori, Japan Zoran Gavrilovie , Institute for the Development of Water Resources "Jaroslav Cerni', Jaraslava Cernog, Beograd, Jugoslavia Paolo Ghilardl , Istituto id Idraulica, Politecnico id Milano, Milano, Italy Walter H. Graf, Laboratoire ed Recherches Hydrauliques, Ecole polytechnique ,elardddF Lausanne, Suisse Tadaharu Ishlkawa , Department of Civil Engineering, Tokyo Institute of ,ygolonhceT Tokyo, Japan Koichi Kato , Department of Civil Engineering, Ehime University, Matsuyama, Japan Alberto Lamberti , Hydraulics Institute, University of Bologna, Italy Zivorad Matovie , Institute for the Development of Water Resources "Jaroslav Cer~i', Jarastava Cernog, Beograd, Jugoslavia Giovanni Menduni , Istituto id Idraulica, Politecnico di Milano, Milano, Italy Masanorl Miehiue , Department of Civil Engineering, Tottori University, Tottori, Japan Takahisa Mizuyama, public Works Research Institute, Ministry of construction, Japanese Government, Tsukuba, Japan Luigi Montefuseo , Department of Civil Engineering, University of Florence, Italy Hiroji Nakagawa , Department of Civil Engineering, Kyoto University, Kyoto, Japan Ennio Paris , Department of Civil Engineering, University of Florence, Italy Gary Parker , St. Anthony Falls Hydraulic Laboratory, University of Minnesota, Min- neapolis, Minnesota, USA Massimo Peviani , LS.M.E.S. s.p.a. , Bergamo, Italy Domenico Pianese , Department of Hydraulics, Water Resources Management and Envi- ronmental Engineering, University of Naples, NapoIi, Italy Dieter Rickenmann , Laboratory of Hydraulics, Hydrology and Glaciology, E.T.H.- Zen- trum, Ziirich, Switzerland Fabio Rossi , Institute of Civil Engineering, University of Salerno, Penta di Faseiano, Italy X Helmut Scheuerlein , hcanrebO sciluardyH ,yrotarobaL lacinhceT University ,hcinuM ,hcinuM Germany Frledrich SchSberl Institut fiir Konstruktiven uabessaW dnu ,uablennuT t'htisrevinU ,kcurbsnnI Austria Giovanni Seminara Institute, tIydraulics of University ,aoneG ,aoneG Italy Yoshihiko Shlmizu Department of Civil ,gnireenignE Ehime University, ,amayustaM napaJ Lechostaw Suszka , Institute of ,gnireenigneordyH Polish ymedaca of ,secneicS ,ksnadG dnaloP Tetsuro Tsujlmoto , Department of Civil ,gnireenignE awazanaK ,ytisrevinU ,awazanaK napaJ Marco Tubino , sciluardyH Institute, ytisrevinU of ,aoneG ,aoneG Italy Koichl Suzuki , Deparlmenl of Civil ,gnireenignE Ehi m,ytiserevin U ,amayustaM napaJ Tamotsu Takahashi , Prevention Disaster hcraeseR Institute, Kyoto ,ytisrevinU Kyoto, napaJ G. Vogel , yrotarobaL for sciluardyH dna ciluardyH Structure, University of eht Armed ,secroF Munich, ynamreG I-I.3. Vollmers , yrotarobaL for sciluardyH dna ciluardyH Structure, University of eht Armed ,secroF Munich, ynamreG Hans Peter Willi , Swiss laredeF eciffO for Water ,ymonocE Bern, dnalreztiwS Introduction to the Papers by A. Armanini and G. Di Silvio .1 WATER FLOW IN MOUNTAIN STREAMS One of the features that characterizes most water flow in mountain streams is the large relative roughness. In such a case the roughness elements of typical size ks, say the intrusion within the main flow, have the same order of magnitude as the water depth h ; that is: z=~ h = O(1) 1) and the velocity distribution deviates from the logarithmic law When the relative submergence Z is small enough a roughness sublayer has been recognized near to the bottom, where the velocity distribution tends to become uniform and Reynolds stresses tend to be suppressed [W.II.GRAF in paper A1 and tI.NAKAGAWA et alii in paper A2]. The reduction of measured Reynolds stresses near the bed apparently impairs the values of the bed shear stress ro = pghj, j being the slope, calculated from the total force balance, tt.NAKAGAWA et alii in paper A2 try to explain the characteristics of the roughness sublayer and the apparent discrepancies in terms of eddy shedding from individual roughness elements. As a consequence, hydraulic resistance also deviates from the normM law accepted in case large submergence: Besides the velocity distribution ( and the related estimation of resistance), this deviation also affects the incipient motion condition and sediment transport formulas (Sections 2 and 3). In order to determine the parameters affecting the hydraulic resistance in a mountain stream in clear water conditions it is convenient to apply concepts from dimensional analysis. The shear stress exerted on the bed by the water depends on the following parameters: mean velocity U , water depth h , acceleration due to gravity g , fluid density p , representative diameter of bed material D,, and its size and space distribution n : f(r0, U,h,g,p,D,,n,#)=O 2) By means of ~r-theorem, equation 2) can be expressed as a function of the following dimensionless groups: .f U U h pU-h -,.)= o )3 (~ ' v~' D~ ' ~i where, in the first group, the shear velocity u, = ~/f~ has been introduced. Even if other combinations of different dimensionless groups are possible, the i t- five assumed seem to be suitable to describe the phenomenon under consideration. The first dimensionless group represents the relative resistance and can be expressed also by means of the Darcy-Weisbach friction factor f, or the Ch~zy coefficient X : . . . . U The second group represents the Froude number: Fr = v/~. h The third ratio is the relative submergence: Z = --. D, The fourth group is the Reynolds number: Re = "hTh-~-~ In the natural water courses the turbulent shear stresses prevail over the viscous forces, such that viscosity does not influence the resistance and consequently Reynolds number Re can be overlooked. The fifth parameter n accounts for both the roughness size distribution and its spacing (packing and imbrication). In most cases, even for non-uniform material, the grain-size distribution allows for the definition of a unique representative diameter (e.g. Ds0 or Dgo ) which should be also chosen considering the spacing produced by the flow. By including the n parameter in the definition of representative diameter, one has: