Floods and their computation
Proceedings of the Leningrad Symposium August 1967
Les crues et leur évaluation
Actes du colloque de Leningrad Août 1967 Volume 1
A contribution to the International Hydrological Decade U n e contribution à la Décennie hydrologique internationale
IASH- Unesco - W M O
AIHS-Unesco-OMM
Co-edition Unesco-IASH / Coédition Vnesco-AIHS
1. T h e use of analog and digital computers in hydrology: Proceedings of the Tucson symposium / L'utilisation des calculatrices analogiques et des ordinateurs en hydrologie : Actes du colloque de Tucson.
2. Water in the unsaturated zone: Proceedings of the Wageningen symposium / L'eau dans la zone non saturée : Actes du colloque de Wageningen.
Co-edition Unesco-IASH-WMO / Coédition Unesco-AIHS-OMM
3. Floods and their computation: Proceedings of the Leningrad symposium / Les crues et leur évaluation : Actes du colloque de Leningrad.
Published by Unesco / Publié par ¡'Unesco
4. Representative and experimental basins: Guide to international practice.
4. Les bassins représentatifs et expérimentaux : u n guide des pratiques internationales.
(Will also appear in Russian and Spanish / Paraîtra également en russe et en espagnol.) 5*. Discharge of selected rivers of the world, vol. I / Débits des principaux cours d'eau
du m o n d e , vol. I.
6*. List of international Hydrological Decade Stations of the World / Liste des stations de la Décennie hydrologique internationale existant dans le m o n d e .
* Quadrilingual publication : English - French - Spanish - Russian.
Publication quadrilingue : anglais - français - espagnol - russe.
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the World Meteorological Organization, 41, av. Giuseppe Motta, Geneva, and Unesco, Place de Fontenoy, 75 Paris-7e
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© Unesco/IASH 1969 Printed in Belgium SC.68/XX.4/AF
Preface
T h e International Hydrological Decade ( 1 H D ) 1965-1975 w a s launched by the thir- teenth session of the General Conference of Unesco to promote international co-operation in research and studies and the training of specialists and technicians in scientific hydro- logy. Its purpose is to enable all countries to m a k e a fuller assessment of their water resources and a more rational use of them as m a n ' s demands for water constantly increase in face of developments in population, industry and agriculture. In 1968 National Committees for the Decade had been formed in 100 of Unesco's 122 M e m b e r States to carry out national activities and to contribute to regional and international activities within the programme of the Decade. T h e implementation of the programme is supervised by a Co-ordinating Council, composed of twenty-one M e m b e r States selected by the General Conference of Unesco, which studies proposals for developments of the pro- g r a m m e , recommends projects of interest to all or a large number of countries, assists in the development of national and regional projects and co-ordinates international co- operation.
Promotion of collaboration in developing hydrological research techniques, diffusing hydrological data and planning hydrological installations is a major feature of the pro- g r a m m e of the I H D which encompasses all aspects of hydrological studies and research.
Hydrological investigations are encouraged at the national, regional and international level to strengthen and to improve the use of natural resources from a local and a global perspective. The p r o g r a m m e provides a means for countries well advanced in hydrolo- gical research to exchange scientific views and for developing countries to benefit from this exchange of information in elaborating research projects and in implementing recent developments in the planning of hydrological installations.
A s part of Unesco's contribution to the achievement of the objectives of the I H D the General Conference authorized the Director-General to collect, exchange and dissemin- ate information concerning research on scientific hydrology and to facilitate contacts between research workers in this field. T o this end Unesco has initiated two collec- tions of publications, "Studies and Reports in Hydrology" and "Technical Papers in Hydrology".
T h e collection "Studies and Reports in Hydrology ", is aimed at recording data col- lected and the main results of hydrological studies undertaken within the framework of the Decade as well as providing information on research techniques. Also included in the collection will be proceedings of symposia. Thus, the collection will comprise the compila- tion of data, discussions of hydrological research techniques and findings, and guidance material for future scientific investigations. It is hoped that the volumes will furnish material of both practical and theoretical interest to hydrologists and governments
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participating in the I H D and respond to the needs of technicians and scientists con- cerned with problems of water in all countries.
Unesco and the I A S H have together undertaken the implementation of several impor- tant projects of the I H D of interest to both organizations, and in this spirit a number of joint U n e s c o - I A S H publications are envisaged.
Simular co-operation is under w a y with W M O and several joint U n e s c o - W M O publications are also planned.
Préface
La Décennie hydrologique internationale ( D H I ) 1965-1975 a été ouverte par la Conférence générale de l'Unesco à sa treizième session pour favoriser la coopération internationale en matière de recherches et d'études et la formation de spécialistes et de techniciens de l'hydrologie scientifique. Son but est de permettre à tous les pays d'évaluer plus complè- tement leurs ressources en eau et de les exploiter plus rationnellement, les besoins en eau augmentant constamment par suite de l'expansion démographique, industrielle et agricole. E n 1968, des comités nationaux pour la Décennie ont été constitués dans 100 des 122 États membres de l'Unesco en vue de mener à bien les activités nationales et de participer aux activités régionales et internationales dans le cadre du p r o g r a m m e de la Décennie. C e programme est exécuté sous la direction d ' u n Conseil de coordination composé de vingt et un États membres désignés par la Conférence générale de l'Unesco, qui étudie les propositions d'extension du p r o g r a m m e , r e c o m m a n d e l'adoption de projets intéressant tous les pays ou un grand nombre d'entre eux, aide à la mise sur pied de projets nationaux et régionaux et coordonne la coopération à l'échelon international.
Le p r o g r a m m e de la D H I , qui porte sur tous les aspects des études et des recherches hydrologiques, vise essentiellement à développer la collaboration dans les domaines de la mise au point de techniques de recherches hydrologiques, de la diffusion des données hydrologiques et de l'organisation des installations hydrologiques. U encourage les enquêtes nationales, régionales et internationales visant à accroître et à améliorer l'utilisa- tion des ressources naturelles, dans une perspective locale et générale. Il offre la possibilité aux pays avancés en matière de recherches hydrologiques d'échanger des idées, et aux pays en voie de développement de profiter de ces échanges d'information pour l'élabo- ration de leurs projets de recherches et pour la planification de leurs installations hydrolo- giques selon les derniers progrès réalisés.
Pour permettre à l'Unesco de contribuer au succès de la D H I , la Conférence générale a autorisé le Directeur général à rassembler, échanger et diffuser des renseignements sur les recherches d'hydrologie scientifique et à faciliter les contacts entre chercheurs de ce domaine. A cette fin, l'Unesco publie deux nouvelles collections : « Études et rapports d'hydrologie » et « Documents techniques d'hydrologie ».
L a collection « Études et rapports d'hydrologie» a pour but de présenter les données recueillies et les principaux résultats des études hydrologiques effectuées dans le cadre de la Décennie, et de fournir des renseignements sur les techniques de recherche. O n y trou- vera aussi les actes de colloques. Cette collection comprendra donc des données, l'exposé de techniques de recherches hydrologiques et des résultats de ces recherches, et une documentation pour des travaux scientifiques futurs. O n espère que ces volumes fourni- ront aux hydrologues et aux gouvernements qui participent à la D H I des matériaux d ' u n
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intérêt tant pratique que théorique et qu'elle répondra aux besoins des techniciens et des h o m m e s de science qui s'occupent, dans tous les pays, des problèmes de l'eau.
L'Unesco et l ' A I H S ont entrepris de réaliser conjointement plusieurs projets impor- tants de la D H I qui les intéressent l'une et l'autre; dans cette perspective, elles ont prévu un certain nombre de publications U n e s c o - A I H S .
D e m ê m e , des publications c o m m u n e s U n e s c o - O M M résulteront de projets auxquels les deux organisations coopèrent actuellement.
Table of contents Table des matières
TOME I — VOLUME I
Foreword / Avant-propos 12 List of participants / Liste des participants 17
Opening address / Discours d'ouverture 25
Part I General problems: Theory of rainfall flood formation and methods of flood computation
Partie I Généralités : La théorie de la formation
et les méthodes du calcul des crues provoquées par la pluie
O n principles of estimation methods of m a x i m u m discharge S. N. Kritsky and
M. F. Menkel 29 Determination of the probability distribution of m a x i m u m discharges on basis of
all observed floods W. Strupczewski 41 Improved precision of future high floods G.M. Panchang 51
Principles for elaboration of mathematical runoff models G. P. Kalinin,
L.S. Kuchment, and V.I. Koren 60 A numerical model of the runoff process of mountain rivers U. M. Denisov 65
A n estimate of discharge probabilities / . Csoma 72 The estimation of extreme precipitation as the basis for design floods—Résumé of
practices in the United States V.A.Myers 84 Design rainfall characteristics of the U S S R territory E.A. Smirnova 105
Objective statistical methods of computation and generalization of the parameters
of m a x i m u m rainfall runoff G. A. Alexeyev 114 Application of the method of m a x i m u m runoff computation using the precipita-
tion reduction curves in the Maritsa river basin S. G. Georgiev 128 O n the expediency of using combined series of hydrological characteristics for
flood computation A.I. Chebotarev and BI. Serpik 135 Estimating the accuracy of statistical flood values by means of long-term discharge
records and historical data E. Glos and R. Krause 144 Assessment of a design discharge of a river / . van der Made 152
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Spatial and temporal analysis of m a x i m u m runoff G. P. Kalinin and
N.V.Nikohkaya 174 O n a general theory of duration curve and its application to evaluate the plotting
position of m a x i m u m probable precipitation or discharge S. Banerji and
D.K. Gupta 183 Détermination du débit m a x i m u m de crue possible d'un cours d'eau à partir de
son hydrogramme unitaire et de la courbe « intensité maximale-durée »
D. le Gouriérès 193 Determination of flood discharges using aerial survey V.A. Ouryvaev and
G.M. Lukashenko 201 O n the method of unit hydrograph and modelling of rainfall floods by electronic
analogue computers D. L. Sokolovsky 205 Computation principles of flood hydrographs K.P. Voskresensky 213
Sur la méthodologie de calcul des volumes maxima C. Diaconu 219 Détermination des debits maximaux d'après les traces des crues anciennes
M. Pardé 230 Increasing the accuracy of determination of m a x i m u m discharges and their excee-
dence probability E. V. Boldakov 238 Extrapolation of discharge rating curves using Chezy's formula
R.A. Shestakova 245 Estimation of design flood discharges especially for river valley projects in India
P. Ahuja and R. Shenoy 252 Rainfall flood formation theory and methods of rainfall flood computation
A.N. Befani 259 Experimental study of rainfall runoff A.N. Befani, N.F. Befani,
E.D. Goptchenk, A.G. Ivanenko, T. V. Ockova, and E. V. Terentyev 21A Contribution à la méthodologie de l'évaluation des débits de crue maximaux en
cas d'insuffisance de données J. Rodier 283 Étude théorique et méthodologique de l'abattement des pluies journalières
Y. Brunet-Moret et M. Roche 289 The genetic method of computation of floods caused by storm rainfalls in small
catchment areas in the absence of hydrological data / . Woloszyn 301 Method of computing rainfall floods characteristics U.B. Vinogradov 312 Formation of rainfall floods on small watersheds. Principles of m a x i m u m storm
runoff computation l.L. Zimont and U.G. Suprunov 321 Probable flood discharges of the Po River tributaries U. Raff a 330
M a x i m u m discharge of major rivers in large flood plains in East Pakistan
Faiz Ahmed 336 Formation des crues pluviales et évaluation des m a x i m u m s des débits de crue
R. Hazan 349 Détermination des débits m a x i m u m et des hydrogrammes de crues R. Hazan et
D. Lazarevic 354 Analyse de la durée des crues /. Zsuffa 362
Données à établir sur les averses génératrices de très grandes crues passées o u
futures M. Pardé 368 Evaluation des débits maximaux des crues d'après la seule connaissance des
apports atmosphériques responsables M. Pardé 379 Method of rainfall floods computation and forecasting using discharge data of
small rivers A. G. Levin 390 Computation of m a x i m u m storm discharge of mountain rivers /. V Eguiazarov
and M. V. Tsovyan 396
L a construction de l'hydrogramme unitaire par le m o y e n de l'analogie hydrologi-
que P. Wirth et I. Zsuffa . 404 Analyse de la relation entre les précipitations et le débit de crue à l'aide d'une
triple transformation basée sur la méthode de l'hydrogramme unitaire
G.L. Bukovszky et I. Zsuffa 408 Détermination d u débit m a x i m u m de crue et de sa probabilité de dépassement
dans le cas d'information incomplète J. Jacquet et J. Bernier 419 Évaluation of m a x i m u m rainfall discharge from a region of deficient rainfall
data R.K.Datta and DK. Gupta 432 Determination of the distribution of rainfall floods in large catchments using
hydrometeorological data S. Banerji and D . C. Mantan 442 T h e calculation of rainfall from a hurricane F. Singleton and N. C. Helliwell 450
Method of estimating storm runoff from small drainage basins C. D . Rostomov 462
Flood frequency o n the Krishna River, India G.A.N. Rao 472 Calculation of the m a x i m u m runoff in floods from rainfall over the territories of
the Ukraine and Moldavia (with no or insufficient hydrometrical data)
P.F. Vishnevsky 483 Méthodes pratiques d'estimation des plus grandes crues R. Heras 492
Derivation of a general flood wave hydrograph from a continuous watershed
water balance H. D . Ayers and J. Balek 505 Peak discharge and time of concentration relation to rain intensity investigated
by physical models of watersheds J. Nêmec and M. Moudr-y 510 Essai de classification des crues maximales / . Francou et J.A. Rodier 518 Représentation cartographique simple des pointes pluviométriques ; applications
possibles à l'hydrologie Ch. P. Péguy et H. Vivian 528 Application of probability to spillway design flood estimation G.N. Alexander 536
Bases méthodologiques de calcul d'hydrogrammes de crues pluviales, utilisées pour la prévision des crues par le ministère de l'équipement G. Jamme,
J.L. Lacroix et C. Fabret 544 T h e flood forecasting by a series storage type model M. Sugawara 555
L a méthode du gradex pour le calcul de la probabilité des crues à partir des pluies
P. Guillot et D . Durand 560 General Discussion of Part I 569
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Foreword
Although a large part of hydrological research is devoted to the vital quest for adequate water supplies, problems which arise when water occurs in harmful excesses must also be solved in order to permit the rational utilization of the world's water resources.
Uncontrolled flood waters, damaging property and taking h u m a n lives, have affected nearly every country in the world. The Co-ordinating Council of the I H D recognized the problem of floods and the evaluation of flood characteristics during its first session in Resolution 1-19 which sets up broad priorities on research to be undertaken during the I H D programme. This resolution outlines the main problems of floods and evaluation of flood characteristics as: regional distribution of floods from rain and snowmelt and methods for estimating m a x i m u m flows. Resolution 1-38 of the Co-ordinating Council further emphasizes the need for research on floods by proposing a specific study project concerning m a x i m u m run-off from rainfall and snowmelt.
T o give further impetus to studies of floods, Unesco, in co-operation with the U S S R National Committee for the I H D and the World Meteorological Organization and with the support of the International Association of Scientific Hydrology, organized an International Symposium on Floods and their Computation in Leningrad from
15 to 22 August 1967.
The symposium w a s prepared and conducted by an Organizing Committee and Secretariat under the leadership of the late D r . V . A . Ouryvaev, Director of the State U . S . S . R . Hydrological Institute. It was attended by 248 participants, representing 33 countries from five continents, and six international organizations: Unesco, United Nations Economic Commission for Asia and the Far East, the World Meteorological Organization, the F o o d and Agriculture Organization, the International Council of Scientific Unions and the International Association of Scientific Hydrology.
The scientific programme of the symposium covered the following main subjects:
1. General problems, theory of flood formation and methods of flood computation ; 3. Theory of formation and methods of computation of snowmelt floods;
3. Influence of basin characteristics on the elements of flood hydrographs.
All the meetings of the symposium were plenary. The following scientists were in the chair : D r . V . A . Ouryvaev ( U S S R ) , M r . J. Jacquet (France), D r . K . Szesztay (Hungary), M r . V . A . Myers ( U S A ) , Professor P . O . Wolf ( U K ) , Professor J. Nemefi (Czechoslovakia), Professor A . Volker (ICSU), D r . Ing. L . Dorigo (Italy), Professor L.J. Tison ( I A S H ) , Professor A . A . Sokolov ( U S S R ) .
O n e hundred and five papers, submitted from twenty-five countries, were discussed in relation to the p r o g r a m m e outlined above and are reproduced in these proceedings with minor abbreviations and editing. Reports of discussions on individual papers are given after the papers, while reports of discussions relevant to several papers or the whole of one of the main subjects of the programme are given after each main subject.
It is hoped that these proceedings published jointly by Unesco, W M O and I A S H will be of value in transmitting various techniques and theories concerning the computa- tion of floods and in establishing methods of flood prevention and control.
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Avant-propos
L a recherche hydrologique a principalement pour objet la prospection, essentielle pour l'humanité, de sources d'approvisionnement adéquat en eau, mais les problèmes qui se posent lorsque l'eau est trop abondante doivent être résolus, si l'on veut parvenir à une exploitation rationnelle des ressources mondiales en eau.
Les crues non contrôlées ont causé des dégâts matériels et des pertes en vies humaines dans presque tous les pays du m o n d e . L e Conseil de coordination de la D H I a pris en considération à sa première session le problème que posent les crues et l'évaluation de leurs caractéristiques; il fixe, dans la résolution 1-19, les grands thèmes des recherches à entreprendre en priorité dans le cadre du p r o g r a m m e de la D H I , et définit les principaux problèmes concernant les crues et l'évaluation de leurs caractéristiques c o m m e étant ceux qui ont trait à la répartition géographique des crues dues à la pluie et à la fonte des neiges, et aux méthodes d'évaluation de l'écoulement maximal. L a résolution 1-38 du Conseil de coordination insiste à nouveau sur la nécessité d'entreprendre des recher- ches sur les crues et propose u n projet spécifique d'étude des débits m a x i m a u x dus aux précipitations et à la fonte des neiges.
Pour donner une impulsion nouvelle à l'étude des crues, l'Unesco, en collaboration avec le Comité national de l ' U R S S pour la D H I et l'Organisation météorologique mondiale, et avec l'appui de l'Association internationale d'hydrologie scientifique, a tenu à Leningrad, d u 15 au 22 août 1967, u n Colloque international sur les crues et leur évaluation.
Le colloque a été préparé et dirigé par un Comité organisateur et un Secrétariat ayant à leur tête le regretté Dr V . A . Ouryvaev, directeur de l'Institut hydrologique d'État de l ' U R S S .
Les deux cent quarante huit participants qui ont assisté à ce colloque réprésentaient 33 pays répartis sur les cinq continents et six organisations internationales : l'Unesco, la Commission économique des Nations Unies pour l'Asie et l'Extrême-Orient, l'Organi- sation météorologique mondiale, l'Organisation des Nations Unies pour l'alimentation et l'agriculture, le Conseil international des unions scientifiques et l'Association inter- nationale d'hydrologie scientifique.
Le p r o g r a m m e scientifique d u colloque comportait l'examen des grands problèmes suivants :
1. Problèmes généraux, théorie de la formation des crues provoquées par la pluie et méthodes permettant de les évaluer;
2. Théorie de la formation des crues dues à la fonte des neiges, et méthodes d'évaluation de ces crues ;
3. Influence des caractéristiques des bassins sur les éléments de l'hydrogramme de crues.
Tous les travaux du colloque se sont déroulés en séance plénière. L a présidence a été assurée par les spécialistes suivants : Dr V . A . Ouryvaev ( U R S S ) , M . J . Jacquet (France), Dr K . Szesztay (Hongrie), M r . V . A . Myers (États-Unis d'Amérique), Professeur P . O . Wolf (Royaume-Uni), Professeur J. N e m e c (Tchécoslovaquie), Professeur A . Volker (CIUS), Dr L . Dorigo (Italie), Professeur L.J. Tison (AIHS), Professeur A . A . Sokolov ( U R S S ) .
Cent-cinq communications, présentées par 25 pays, ont été examinées dans le cadre du programme défini ci-dessus ; les textes de ces communications, légèrement condensés et retouchés par endroits figurent dans les présents actes et sont suivis d u compte- rendu des débats auxquels ils ont donné lieu. Les comptes-rendus de discussions qui ont porté sur plusieurs communications o u sur l'une des grandes questions à l'ordre du jour figurent à la suite de chacune de ces questions.
O n espère que ces actes, publiés conjointement par l'Unesco, l ' O M M et l ' A I H S , feront connaître plusieurs techniques et théories relatives à l'évaluation des crues et qu'ils contribueront ainsi à l'adoption de méthodes permettant de les prévenir et de se défendre contre elles.
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Liste des participants
A U S T R A L I A
JOHNSON, R . B., State Rivers and Water Supply Commission, Armadale, Victoria.
A U S T R I A
SCHREIBER, H . , Central Hydrographical Office, Vienna.
BELGIUM
T I S O N , L.J. (see under, International Organizations, below).
BULGARIA
G E O R G I E V , S . G . , Institute of Hydrology and Meteorology, Sofia.
M A R T C H I N K O V , B . , National Committee for the I D H ; Civil Engineering Institute, Sofia.
P A N A I O T O V , T . P . , Institute of Hydrology and Meteorology, Sofia.
B U R M A
H T W E Y I , U . , Meteorological Department, Rangoon.
C A M E R O U N
LE G O U R I È R E S , D . , Université Fédérale du Cameroun, Yaounde.
C A N A D A
C O L L I E R , E . F . , Inland Waters Branch, Department of Energy, Ottawa.
F I N N , W . D . , University of British Columbia, Vancouver.
K E N N E D Y R.J., Queen's University, Kingston, Ontario.
M C M U L L E N , D . N . , Canadian Meteorological Service, Toronto.
V E R S C H U R E W , J. P., University of Alberta, Edmonton.
CUBA
A L V A R E Z RODRICUEZ, A . , National Institute of Water Resources, Havana.
C Z E C H O S L O V A K I A
B A L C O , M . , Institute of Hydrology and Hydraulics, Bratislava, B A L E K , Y . , Institute of Hydrodynamics, Academy of Science;. prague.
D Z U B A K , M . , Institute of Hydrology and Hydraulics, Bratislava.
H L A D N Y , J., Hydrometeorological Institute, Prague.
G R A D E K , F . , Agricultural Institute, Prague.
K R Í Z , V . , Hydrometeorological Institute, Prague.
M O U D R Y , M . , Agricultural Institute, Prague.
N È M E C , J., National Committee for the I H D , Agricultural Institute, Prague.
P R O C H A Z K A , J., Hydraulic Research Institute, Bratislava.
R O M P O R T L , B . , Agricultural Institute, Prague.
Z A T K A L I K , G . , Hydrometeorological Institute, Bratislava.
Z E L E N Y , V . , Research Institute of Amelioration, Prague.
FINLAND
H Y V Á R I N E N , V . , Hydrological Office, Helsinki.
L E M M E L A , R . , Hydrological Office, Helsinki.
V I R T A , J., Hydrological Office, Helsinki.
FRANCE
B E R N I E R , J., Electricité de France, Centre de Recherches et d'Essais, Chatou.
C H A R T I E R , M . C . , Sorbonne. Institut de Géographie, Paris.
D E N E A U , V . , Electricité de France, Centre Hydrométéorologique « Massif Central », Brive.
E S T I E N N E , J., Electricité de France, 5e Circonscription Electrique, Toulouse.
F A B R E T , C . J . , Service des Ponts et Chaussées, Périgueux.
J A C Q U E T , J. C , Electricité de France, Centre de Recherches et d'Essais, Chatou.
J A M M E , G . P . , Direction des Ports Maritimes et des Voies Navigables, Service Central Hydrolo- gique, Paris.
L A C R O I X , J. L . , Agence de Bassin Rhône-Méditerranée Corse, Lyon.
L E F E V R E , R . , Office de la Recherche Scientifique et Technique Outre M e r ( O R S T O M ) , Service Hydrologique, Paris.
M A I S T R E , P . , Bureau Central d'Etudes pour les Equipements d'Outre M e r , Paris.
P É G U Y , C H . P . , Centre National de la Recherche Scientifique, Saint-Martin d'Hères.
R O C H E , M . F . , O R S T O M , Service Hydrologique, Paris.
R O D I E R , J. A . , O R S T O M , Service Hydrologique, Paris.
S E R R A , L . , Electricité de France, Centre de Recherches et d'Essais, Chatou.
G A B O N
R O U S S E L , J., Ministère des Travaux Publics, Libreville.
FEDERAL REPUBLIC OF G E R M A N Y
S C H U L T Z , G . A . , Technical College, Department of Water Resources Development, Munich.
EASTERN G E R M A N Y
B A U E R , D . , T h e Middle Elba-Sude-Elde Water Authority, Magdeburg.
D Y C K , S., National Committee for the I H D ; Technical College, Institute of Hydrology, Dresden.
G R A S N I C K , H . J . , Hydrometeorological Research Institute, Berlin.
L A U T E R B A C H , D . , Institute for Water Resources Development, Berlin.
R A C H N E R , M . , Meteorological Office, Halle.
R E I F E R T , J., Planning and Design Office, Halle.
H U N G A R Y
L Á S Z L Ó F F Y , W . , National Committee for the I H D ; Research Institute for Water Resources Development, Budapest.
L U K A C S , L . , Civil Engineer.
S A L A M I N , P . , Université Technique; Société Hydrologique Hongroise, Budapest.
S Z E S Z T A Y , K . , National Committee for the I H D ; Research Institute for Water Resources Develop- ment, Budapest.
Z S U F F A , I., Direction des Eaux, Székesfehárvár.
ICELAND
RisT, S., State Electricity Authority, Reykjavik.
18
INDIA
R A O , G . A . N . , Public Works Department of Andhra Pradesh, Hyderabad.
ITALY
BENDINI, C A R L O , Hydrographie Office of the Arno River Basin, Pisa.
D O R I G O , LIVIO, Civil Engineer.
TONINI, M . , National Electricity Authority.
JAPAN
K I K K A W A , H . , Institute of Technology, Tokyo.
K E N Y A
J E N K I N S O N , A . F . , University College, Nairobi.
MONGOLIA
M T A G M A R Z H A V , B . , National Committee for the Hydrometeorological Service, Ulan-Bator.
N E T H E R L A N D S
V A N D E R M A D E , J. W . , Water Management Authority, The Hague.
M A R T I J N , T . G . , Government Institute for Water Supply, The Hague.
SIJBESMA, R . P . , River Studies Section, Water Management Authority, A r n h e m .
W E M E L S F E L D E R , P . J., Hydrometrical Department, Water Management Authority, The Hague.
N O R W A Y
J A K H E L L N , A . , Norwegian Meteorological Institute, Oslo.
R U S E , V . , "Erik Raestad Als " , Consulting Engineers, Lysaker.
T O L L A N , A . , National Committee for the I H D , Oslo.
W I N G A R D , B . , Norwegian Water Course and Electricity Board, Oslo.
P O L A N D
M E Y E R , W . , National Committee for the I H D , Warsaw.
M I K U L S K I . Z . P . , N a t i o n a l Committee for the I H D ; National Institute for Hydrology and Meteoro- logy, Warsaw.
R O M A N I A
M O C I O R N I T A , C , Institut de Recherches Hydrotechniques, Bucarest.
P L A T A G E A , G . , Institut de Recherches Agrotechniques et Pédologiques, Bucarest.
P O D A N I , M . , Comité National de la D H I ; Direction Hydrométéorologique, Bucarest.
R W A N D A
G É N Y , P . R . , Ministère de l'Agriculture, Vigali.
SWEDEN
T R Y S E L I U S , O . , Swedish Meteorological and Hydrological Institute, Stockholm.
T U R K E Y
C Ó N T Ü R K , H . , Electrical Power Study Administration, Ankara.
U G A N D A
K A Y O N D O , G . , Water Development Department, Ministry of Mineral and Water Resources, Entebbe.
U N I O N O F SOVIET SOCIALIST R E P U B L I C S A I V A S O V A , V . I . , National Comission of the U S S R , Unesco, M o s c o w .
A K S A R I N , N . N . , T h e Uzbek S S R Office of the Hydrometeorological Service, Tashkent.
A L E K I N , O . A . , Leningrad Hydrometeorological Institute, Leningrad.
A L E X E Y E V , G . A . , State Hydrological Institute, Leningrad.
A R U K A E V , K . M . , Estonian S S R Office of the Hydrometeorological Service, Tallin.
A T K A R S K A Y A , T . N . , Council for the Study of Productive Forces, State Planning Committee, M o s c o w .
B A B C H E N K O , V . N . , T h e Urals Office of the Hydrometeorological Service, Sverdlovsk.
B A L A N I N , V . V . , Leningrad Institute of Water W a y s , Leningrad.
B E F A N I , A . N . , Odessa Hydrometeorological Institute, Odessa.
B E F A N I , N . F . , Odessa Hydrometeorological Institute, Odessa.
B O G O J A V L E N S K Y , Y . N . , U S S R Committee for the I H D ; Chief Administration of the Hydro- meteorological Service, M o s c o w .
B O L D A K O V , E . V . , R o a d Construction Research Institute, M o s c o w .
B R A G I L E N S K A Y A , E . A . , Byelorussian ResearcS Institute of Reclamation and Water Resources Management, Minsk.
B U R T S E V , P . N . , State Hydrological Institute, Leningrad.
B Y D I N , F . I., Northern Research Institute for Hydraulic Engineering and Reclamation, Leningrad.
B Y K O V , V . D . , M o s c o w State University, M o s c o w .
B Y S H O V E T S , L . B . , Ukrainian Hydrometeorological Research Institute, Kiev.
C H E B O T A R E V , A . I., State Hydrological Institute, Leningrad.
C H E K U S H K I N A , T . A . , Ukrainian Hydrometeorological Research Institute, Kiev.
C H E R E N K O V , A . E . , North-Caucasian Office of the Hydrometeorological Service, Rostov-on-Don.
C H E R K A V S K Y , S . K . , Chief Administration of the Hydrometeorological Service, M o s c o w . C H K H I K V A D Z E , M . K . , State Hydrological Institute, Leningrad.
C H V E T S , G . I . , Council for the Study of Productive Forces of the Ukrainian S S R , Kiev.
D A N I L O V I C H , M . Y . , Ministry of Geology, M o s c o w . D A V Y D O V , L . K . , Leningrad State University, Leningrad.
D E N I S O V , V . M . , Institute Promniiproject, Tashkent.
D E N I S O V , Y . M . , Hydrometeo'ological Research Institute of Central Asia, Tashkent.
D O M A N I T S K Y , A . P . , State Hydrological Institute, Leningrad.
D Y S H K O , E . I., Office of Technical Standardization, M o s c o w .
E G U I A S A R O V , I. V . , Research Institute of Water Problems and Hydraulic Engineering of the Armenian A c a d e m y of Sciences, Yerevan.
E P S T E I N , A . I., Central Chernozyom Region Office of the Hydrometeorological Service, Kursk.
E V T O D I E V , Y . A . , Kamchatka Office of the Hydrometeorological Service, Petropavlovsk-Kam- chatsky.
G E O R G I E V S K Y , Y . M . , Leningrad Hydrometeorological Institute, Leningrad.
G E R S H M A N , A . E . , Hydroproject Institute, Leningrad Branch, Leningrad.
G O L U B E V , V . S . , Valdai Hydrological Research Laboratory, Valdai.
G O R C H A K O V , A . M . , Far Eastern Hydrometeorological Research Institute, Vladivostok.
G O R O S H K O V , I.F., Leningrad Hydrometeorological Institute, Leningrad.
G O U R E V I T C H , M . I . , State Hydrological Institute, Leningrad.
G O U S E V A , A . T . , Ukrainian S S R Office of the Hydrometeorological Service, Kiev.
G R I N , A . M . , Geographical Institute of the U S S R A c a d e m y of Sciences, M o s c o w . G R U S H E V S K Y , M . S . , State Hydrological Institute, Leningrad.
G U I L D E N B L A T T , I . D . , Hydroproject Institute, M o s c o w .
H A R T Z M A N , I.N., Far Eastern Hydrometeorological Research Institute, Vladivostok.
I V A N E N K O , A . G . , Odessa Hydrometeorological Institute, Odessa.
K A L I N I N , G . P . , M o s c o w State University, M o s c o w . K A R A K U L K O , V.J., Giprovodkhoz Institute, M o s c o w . K A R A U S H E V , A . V . , State Hydrological Institute, Leningrad.
K H A R C H E N K O , S.I., State Hydrological Institute, Leningrad.
K H E R H E U L I O D Z E , 1.1., Transcaucasian Hydrometeorological Research Institute, Tbilisi.
K H M A L A D Z E , G . N . , Transcaucasian Hydrometeorological Research Institute, Tbilisi.
K H O U P E N I A , M . B . , Georgian S S R Office of the Hydrometeorological Service, Tbilisi.
K O N D R A T J E V , N . E . , State Hydrological Institute, Leningrad.
K O N O N O V A , A . I., K o l y m a Office of the Hydrometeorological Service, M a g a d a n . K O N S T A N T I N O V , A . R . , Ukrainian Hydrometeorological Research Institute, Kiev.
K O R E N , V . I., U S S R Hydrometeorological Research Centre, M o s c o w .
20
K O R Z O U N , V . I . , U S S R Committee for the I H D ; Chief Administration of the Hydrometeoro- logical Service, M o s c o w .
K O V A L E V , L . M . , Hydroproject Institute, M o s c o w . K O V Z E L , A . G . , State Hydrological Institute, Leningrad.
K O Z N O V , S.P., North-Western Office of the Hydrometeorological Service, Leningrad.
K R A S I L O V , P . A . , Teploelektroprojekt Institute, M o s c o w . K R A S N I K , M . G . , Byelorussian Technological Institute, Minsk.
K R A V C H E N K O , N . A . , Moldavian S S R Office of the Hydrometeorological Service, Kishinev.
K R I T S K Y , S . N . , M o s c o w Laboratory of the State Hydrological Institute, M o s c o w . K U C H M E N T , L . S., U S S R Hydrometeorological Research Centre, M o s c o w . K U K S I N , I.E., Byelorussian Research Institute for Water Problems, Minsk.
K U P R I A N O V , V . V . , State Hydrological Institute, Leningrad.
K U S I N , P . S . , State Hydrological Institute, Leningrad.
K U S M I N , P . P . State Hydrological Institute, Leningrad.
K U Z N E T S O V , I. V . , North-Western Office of the Hydrometeorological Service, Leningrad.
K U Z N E T S O V , V . I . , Valdai Hydrological Research Laboratory, Valdai.
L A P T I E V , P . P . , Trans-Baikal Office of the Hydrometeorological Service, Chita.
L E O N T J E V S K Y , B . B . , Hydroproject Institute, M o s c o w . L E S K O V , G . A . , Hydroproject Institute, M o s c o w .
L E V I N , A . G . , U S S R Hydrometeorological Research Centre, M o s c o w . LIVSHITS, I. M . , Byelorussian Polytechnical Institute, Minsk.
L U K A S H E N K O , G . M . , State Hydrological Institute, Leningrad.
M A K A R E V I C H , T . N . , State Hydrological Institute, Leningrad.
M A K H N E V A , A . A . , Lithuanian S S R Office of the Hydrometeorological Service, Vilnius.
M A N O I M , L . F . , State Hydrological Institute, Leningrad.
M E N K E L , M . F . , M o s c o w Laboratory of the State Hydrological Institute, M o s c o w .
M I A S N I K O V A , E . V . , Scientific Council of Multipurpose Use and Conservation of Water Resources, M o s c o w .
M I K H A I L O V , A . N . , Hydrometeorological Publishing House, Leningrad.
M I K H A I L O V , S . A . , Chief Administration of the Hydrometeorological Service, M o s c o w . M I K H A I L O V A , V . L . , Kirgizian Research Institute for Water Management, Frunze.
M I L J U K O V , P. I., U S S R Hydrometeorological Research Centre, M o s c o w . M O K L I A K , V . L . , Ukrainian Hydrometeorological Research Institute, Kiev.
M O L I T V I N , P. V . , Guipronickel Institute, Leningrad.
M O L O K O V , F . P . , State Institute for Water W a y s Design, M o s c o w . M U R A N O V , A . P., State Hydrological Institute, Leningrad.
N A R O D E T S K A Y A , R.J., Rosguiprovodkhoz Institute, M o s c o w .
N E C H A E V A , N . S . , U S S R Hydrometeorological Research Centre, M o s c o w . N I K O L S K A Y A , N . V . , M o s c o w State University, M o s c o w .
O D R O V A , T . V . , Odessa Hydro-Meteorological Institute, Odessa.
O K H I N C H E N K O , A . I., State Hydrological Institute, Leningrad.
O U R Y V A E V , V . A . , State Hydrological Institute, Leningrad.
P A S T O R S , A . A . , Latvian S S R Office of the Hydrometeorological Service, Riga.
P I N K O V S K Y , S.I., State Hydrological Institute, Leningrad.
P L I T K I N , G . A . , State Hydrological Institute, Leningrad.
P O P O V , A . N . , Valdai Hydrological Research Laboratory, Valdai.
P O P O V , E . G . , U S S R Hydrometeorological Research Centre, M o s c o w . P O P O V , O . V . , State Hydrological Institute, Leningrad.
P R O S K O U R I A K O V , B . V . , State Hydrological Institute, Leningrad.
P U E S T O V O I T , S . F . , Kiev State University, Kiev.
R E S N I K O V S K Y , A . Sh., Energoselprojekt Institute, M o s c o w .
R O S T O M O V , G . D . , Transcaucasian Hydrometeorological Research Institute, Tbilisi.
R U D N E V , A . S., Yakutsk Office of the Hydrometeorological Service, Yakutsk.
R U S I N , N . P . , Main Geophysical Observatory, Leningrad.
S A P O Z H N I K O V , V . L . , U S S R Hydrometeorological Research Centre, M o s c o w . S E R P I K , B.I., State Hydrological Institute, Leningrad.
S H E B E K O , V . F . , Byelorussian Research Institute of Reclamation and Water Resources M a n a g e - ment, Minsk.
S H E S T A K O V A , R . A . , State Hydrological Institute, Leningrad.
S H I K L O M A N O V , I. A . , Leningrad Hydrometeorological Institute, Leningrad.
S I D O R K I N A , L . M . , Guiprovodkhoz Institute, Leningrad.
S M I R N O V A , E . A . , State Hydrological Institute, Leningrad.
S O K O L O V , A . A . , State Hydrological Institute, Leningrad.
S O L O P O V , A . V . , Research Institute of Hydraulic Engineering and Reclamation, M o s c o w . S O K O L O V S K Y , D . L . , State Hydrological Institute, Leningrad.
S O S E D O V , L . S., Institute of Hydrogeology and Hydrophysics of the Kazakh S S R Academy of Sciences, Alma-Ata.
S P E N G L E R , O . A . , State Hydrological Institute, Leningrad.
S R I B N V , M . P h . , Council for Water Management Problems of the U S S R Academy of Sciences, M o s c o w .
S T R U Z E R , L . R . , Main Geophysical Observatory, Leningrad.
S U M A R O K O V A , V . V . , Kirgiz S S R Office of the Hydrometeorological Service, Frunze.
S U P R U N O V , U . G . , Khabarovsk Railway Institute, Khabarovsk.
S V A N I D Z E , G . G . , Georgian Research Energetics Institute, Tbilisi.
T A M A Z I A N , A . A . , Armenian S S R Office of the Hydrometeorological Service, Yerevan.
T E R E N T J E V , E . V . , Odessa Hydrometeorological Institute, Odessa.
TERSIEV, F . S., Murmansk Office of the Hydrometeorological Service, Murmansk.
T R E S H N I K O V , A . F . , Arctic and Antarctic Research Institute, Leningrad.
T S O V Y A W , M . V . , Research Institute of Water Problems and Hydraulic Engineering of the Armenian Academy of Sciences, Yerevan.
T S V E L O D U B , N . I . , Guiprovodkhoz Institute, M o s c o w .
V I N O G R A D O V , U . B . . Kazakh Hydrometeorological Research Institute, Alma-Ata.
V I S H N E V S K Y , P. F., Ukrainian Hydrometeorological Research Institute, Kiev.
V O S K R E S E N S K Y , K . P . , State Hydrological Institute, Leningrad.
Y A B L O K O N , U . E . , Central Regions Office of the Hydrometeorological Service, M o s c o w . Y U N U S O V , G . R . , Voronezh State University, Voronezh.
Z A V J A L O V , K . D . , State Hydrological Institute, Leningrad.
Z A S U S K I N , V . N . , Irkoutsk Office of the Hydrometeorological Service, Irkoutsk.
Z H E L E Z N I A K , I. A . , Ukrainian Hydrometeorological Research Institute, Kiev.
Z H O U R A V L E V , M . M . , Road Construction Research Institute, M o s c o w . Z I M O N T , I.L., V O D G E O . Research Institute, M o s c o w .
Z O L O T U K H I N A , T . V . , State Hydrological Institute, Leningrad.
Z U B O E N O K , L.I., Main Geophysical Observatory, Leningrad.
UNITED K I N G D O M OF G R E A T BRITAIN A N D N O R T H E R N IRELAND C O L E , G . , Ministry of Agriculture, London.
M A N S E L L - M O U L L I N , M . Binnie and Partners, Consulting Engineers, London.
R O D D A , J.C., Hydrological Research Unit, Wallingford, Berkshire.
S I N G L E T O N , F., Meteorological Office, Bracknell, Berkshire.
W O L F , P . O . , The City University, Department of Civil Engineering, London.
UNITED STATES OF AMERICA
H O L T A N , H . N . , Hydrograph Laboratory, U . S . Department of Agriculture, Beltsville, Maryland.
M Y E R S , V. A . , Office of Hydrology, Weather Bureau, Silver Spring, Maryland.
R O G E R S , P. Ph., Harvard University, Cambridge, Massachusetts.
S N Y D E R , F. F., Corps of Engineers (retired); Hydrologie Engineering Consultant, Washington, D . C .
STIPP, J. R., Board of Engineers for Rivers and Harbors, Washington, D . C . W H I P K E Y , R . Z . , Northeastern Forest Experiment Station, Columbus, Ohio.
Y U G O S L A V I A
ANDREJEVIC, D . , "Energoproject "—Engineering and Consulting Co., Belgrade.
D J O R D J E V I C , B . , "Jaroslav Cesni " Institute for Development of Water Resources, Belgrade.
D J O R D J E V I Ô , N . , "Jaroslav Cesni " Institute for Development of Water Resources, Belgrade.
I V A N O V I C , M . , National Committee for the I H D , Belgrade.
L A Z A R E V I C , D . , "Energoproject " Engineering and Consulting C o . , Belgrade.
M E L E N T I J E V I C , M . , "Energoproject" Engineering and Consulting C o . , Belgrade.
V Á I D A , L . , "Energoproject" Engineering and Consulting C o . , Belgrade.
22
INTERNATIONAL ORGANIZATIONS
UNITED NATIONS EDUCATIONAL, SCIENTIFIC A N D CULTURAL ORGANIZATION (UNESCO)
B O C H Í N , N . A . , Secretariat of Co-ordinating Council for I H D .
W O R L D METEOROLOGICAL ORGANIZATION (WMO) FORSMAN, A .
MELDER, O. M .
INTERNATIONAL ASSOCIATION OF SCIENTIFIC H Y D R O L O G Y (IASH) TISON, L.J.
INTERNATIONAL COUNCIL OF SCIENTIFIC UNIONS (ICSU) VOLKER, A .
F O O D A N D AGRICULTURE ORGANIZATION (FAO) KREUTZER, H .
E C O N O M I C COMMISSION FOR ASIA A N D T H E FAR EAST (ECAFE) BURLIKOV, V. S.
Opening address
D r . V . A . O U R Y V A E V , Chairman of the Organizing Committee, Director of the State Hydrological Institute ( U S S R ) .
Dear Colleagues! Ladies and gentlemen! Comrades!
The Organizing Committee of the Symposium has the honour to greet you—hydrologists and hydrometeorologists, scientists and engineers, representatives of m a n y countries of Europe, Asia, Africa, America and Australia on the occasion of your arrival in the city of Lenin.
W e greet the representatives of Unesco, the World Meteorological Organization, the International Council of Scientific Unions, the International Association of Scientific Hydrology, the F o o d and Agriculture Organization, and the Economic Commission for Asia and the Far East attending the Symposium.
W e are sure that this scientific conference will be a success; it will be accompanied by the spirit of creative co-operation of scientists from different countries, and w e shall manage to improve the solving of flood problems which are undoubtedly of practical interest for all the countries of the world to protect them from floods and inundation, and to establish flood control as well.
For more than two and a half years successful work has been undertaken to fulfil the programme of the International Hydrological Decade. This programme includes projects connected with the solving of problems for the computation of flood runoff, and thus our symposium will at the same time serve towards fulfilment of the programme of international co-operation in the domain of hydrology. The programme of the symposium was prepared by the U S S R National Committee for the International Hydrological Decade; it was negotiated with Unesco, the World Meteorological Organization and the International Association of Scientific Hydrology, and is submitted to you in the form of groups of reports according to principal themes and problems of flood runoff, namely: theory of formation of rainfall and snowmelt flood runoff, problems connected with the evaluation of the influence of natural factors on the flood regime, problems of theoretical and practical computation of flood runoff and the availability, insufficiency and even absence of data of direct measurement for various natural conditions in different countries.
Finally, the programme of the symposium represents to some extent the problems connected with the hydrometry of flood runoff. T h e hydrologists of the Soviet Union pay m u c h attention to research on floods, and they have presented a great number of reports for the symposium. A s the programme is so concentrated w e had to select only 36 reports of Soviet hydrologists.
25
The problem of flood runoff in the Soviet Union is reflected in numerous scientific investigations in the domain of theory, experiments and practice of flood runoff computa- tion. Practically, these reports m a y be represented in the form of technical instructions and generalization of methods of computation of spring flood runoff parameters on the rivers of the U S S R .
It is quite evident that, in the immediate future standards for construction projects and for the computation of the elements of rainfall flood runoff will be worked out.
W e hope that the U S S R experience will be useful to those working in the domain of flood runoff in other countries. W e shall listen to your reports with great attention.
W e should like to k n o w the results of research on flood runoff performed by our col- leagues in other countries of the world.
It should be mentioned that hydrologists from France, India, Hungary, U S A , Poland, Japan and m a n y other countries have submitted a great number of very interesting reports for the symposium.
The proposal of the Soviet Union to hold the symposium in the city of Leningrad was encouraged by the international organizations. Unesco, W M O and I A S H gave their support to the proposal and informed scientists of different countries. A s a result, more than 100 different reports from 24 countries will be discussed at the symposium.
T w o hundred participants from 30 countries are already assembled here, and still more are on their w a y to Leningrad. M a n y accompanying persons and guests have arrived. Thus, w e are ready to start our work.
Dear colleagues, allow m e to announce that the Symposium on Floods and their Computation, organized by Unesco in co-operation with the U S S R National Commitee for the 1 H D , W M O and I A S H is open.
Discours d'ouverture
D r . V . A . Ouryvaev, Président d u Comité Organisateur, Directeur del'Institut hydrologique d'État ( U R S S ) .
Chers Collègues, Mesdames, Messieurs, Camarades,
Le Comité Organisateur du Colloque a l'honneur de saluer les hydrologues, hydro- météorologues, h o m m e s de sciences et ingénieurs représentant de nombreuses contrées d'Europe, d'Asie, d'Afrique, d'Amérique et d'Australie à l'occasion de leur arrivée dans la cité de Lénine.
N o u s saluons les représentants de l'Unesco, de l'Organisation Météorologique M o n - diale, du Conseil International des Unions Scientifiques, de l'Association Internationale d'Hydrologie Scientifique, de l'Organisation pour la Nourriture et l'Agriculture, de la Commission Économique pour l'Asie et l'Extrême-Orient, qui assistent au Colloque. N o u s s o m m e s certains que cette réunion scientifique sera u n succès, qu'elle sera suivie avec u n esprit de coopération créatrice d ' h o m m e s de sciences de divers pays et qu'elle aidera à améliorer la solution des problèmes posés par les crues qui sont indubitablement d'un intérêt pratique pour toutes les contrées du m o n d e pour les prémunir des crues et des inondations et également pour établir u n contrôle des crues.
Depuis plus de deux ans et demi, un travail plein de succès a été entrepris pour réaliser le programme de la Décennie Hydrologique Internationale. C e programme comporte des projets en relation avec la solution de problèmes pour la prévision de l'écoulement de crues si bien que notre colloque servira en m ê m e temps à remplir le programme de coopération internationale dans le domaine de l'hydrologie. L e programme du colloque a été préparé par le Comité National de l ' U R S S pour la Décennie hydrologique et il fut négocié avec l ' U N E S C O , l'Organisation Météorologique Mondiale, l'Association Internationale d'Hydrologie Scientifique et il vous est maintenant soumis sous forme de groupes de rapports d'après les thèmes et problèmes principaux de l'écoulement des crues, notamment la théorie de formation des crues dues à la pluie et à la fusion de la neige, les problèmes en relation avec l'évaluation et la prévision des crues dans les cas d'existence, d'insuffisance et m ê m e d'absence de mesures directes pour les diverses conditions natu- relles dans différents pays.
Enfin, le programme du colloque présente avec une certaine extension les problèmes se rapportant à l'hydrométrie des crues. Les hydrologues de l'Union Soviétique accordent une grande attention aux recherches sur les crues et ils ont présenté un nombre assez élevé de rapports pour le colloque. C o m m e le programme du colloque est assez concentré, nous avons choisi seulement 36 rapports d'hydrologues soviétiques.
Le problème des crues en Union Soviétique est attaqué par de nombreuses recherches 27
scientifiques dans les domaines de la théorie, de l'expérience et de la pratique des prévisions. E n pratique, ces rapports constituent une instruction technique et une généra- lisation des méthodes d'évaluation des paramètres des crues de printemps sur les rivières de l ' U R S S .
Il est évident que dans un proche avenir une standardisation pour les projets de construction et pour l'évaluation des crues causées par la pluie pourra être établi.
N o u s supposons que l'expérience de l ' U R S S sera utile à ceux qui travaillent dans le domaine des crues dans d'autres pays.
Il doit être mentionné que les hydrologues de France, d'Italie, de Hongrie, des États- Unis, de Pologne, du Japon et de beaucoup d'autres pays ont soumis un grand nombre de rapports très intéressants au Colloque.
L a proposition de l'Union Soviétique de tenir le symposium dans la cité de Leningrad a été encouragée par les organisations internationales. L ' U N E S C O , l ' O M M et l ' A I H S donnèrent leur soutien à la proposition et informèrent les h o m m e s de science des divers pays des modalités du Colloque. L e résultat en est que 100 rapports de 24 pays seront discutés à ce colloque.
Plus de 200 participants assistent au Colloque venant de plus de 30 pays : quelques-uns d'entre eux sont encore en chemin vers Leningrad. Beaucoup de personnes accompagnant les participants et des invités sont arrivés. N o u s s o m m e s donc prêts à commencer le travail.
Chers Collègues, permettez-moi d'annoncer que le Colloque sur les Crues et leur Evaluation organisé par l ' U N E S C O en coopération avec le Comité National de l ' U R S S pour la Décennie, l ' O M M et l ' A I H S est ouvert.
1 General problems
Theory of rainfall flood formation and methods of flood computation
Généralités, la théorie de la formation et les méthodes du calcul des crues
provoquées par la pluie
O n principles of estimation methods of m a x i m u m discharge
S . N . Kritsky, M . F . M e n k e l , State Hydrological institute, Leningrad, U S S R
S U M M A R Y : In calculations of rare extreme discharges with a lack of data, additional information on m a x i m u m discharge of similar rivers and on precipitation must be included. Such methods are effective for rivers with moderate variations of annual m a x i m a typical of snowmelt m a x i m a . Theoretical curves of probability distribution are considered as an extrapolation in the field of small exceedence probabilities of m a x i m u m discharges of individual rivers, and "frequencies' frequencies" curves are considered as the method for combining data for different rivers.
Exceedence probabilities of the highest observed m a x i m a , estimation accuracy, plotting of the design hydrographs for tasks connected with stream flow control are examined.
T h e report also deals with another principal estimation system, based on meteorological data as well as the conditions of its application, i.e. the great variability of discharge m a x i m a , mainly of storm origin, displacement and error of estimation of parameters of the distribution of m a x i m u m discharge probabilities: advantages and disadvantages of this method are discussed.
S o m e basic points of U S S R state standardization of evaluation methods for m a x i m u m discharges are given.
R É S U M É : Dans cet exposé on examine les principes de la définition des débits m a x i m a et la méthode de calcul, basée sur ces principes.
L a singularité du problème consiste dans la non-conformité entre les demandes pratiques du calcul d'avance de m a x i m a extrêmement élevés, observés très rarement en nature, et l'insuffisance des données des observations.
Le principe de la solution de ce problème se base sur l'augmentation des données d'observations sur chaque rivière en partant de deux autres sources d'information : la généralisation des données sur le débit m a x i m u m , provenant de rivières analogues, et la généralisation des données mété- orologiques (les précipitations). Toutes les méthodes ont c o m m e base générale la probabilité.
Pour les rivières avec un changement modéré des m a x i m a annuels, cas typique pour les m a x i m a dus à la fusion de neige, sont effectives les méthodes, basées sur la généralisation des données
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hydrologiques. O n examine les courbes théoriques de la distribution des probabilités c o m m e moyen de l'extrapolation dans la zone du dépassement peu probable des débits maxima pour quelques rivières, et les courbes de « la fréquence des fréquences » c o m m e la méthode de la généralisation des données pour différentes rivières. O n examine les probabilités du dépassement des maxima les plus hauts observés, la précision des évaluations, approches à la construction des hydrogrammes du calcul pour les problèmes associés avec la régularisation des débits.
O n examine aussi un autre principal système de calcul, basé sur la généralisation des données météorologiques, et les conditions de l'utilisation de ce système — une grande variabilité des maxima, particulièrement de l'origine des averses, et, associés avec ce facteur, le déplacement et les erreurs des évaluations des paramètres de la distribution des probabilités des maxima. O n note les mérites et les défauts de cette méthode.
O n cite les principes de la réglementation d'État des calculs des débits maxima, adoptée en U . R . S . S .
A t the present stage of hydrology a n d climatology the theoretical basis for estimation is to consider fluctuations of river flow as a stochastic process. Evaluation of future m a x i m u m possible discharges is practicable only in terms of the probability of exceedence of a given value of discharge.
All the methods for estimation of m a x i m u m discharges are based o n statistical treatment of past data o n m a x i m u m discharge and o n the meteorological events causing them. In this sense all the methods are statistical.
T h e criterion which determines the value of the m a x i m u m flood discharge is the annual probability of exceedence of this value. Information about m a x i m u m discharge fluctuations is limited for any individual river by the period of hydrometric observations.
This principle is also applicable to rivers where m o r e than one high peak caused by rains m a y occur yearly ; the m a x i m u m discharge is characterized by the probability evaluated by ratio to the n u m b e r of years, but not to that of individual flood peaks.
T o secure the safety of hydraulic structures it is necessary to forecast extremely large and very rare floods, the exceedence probability of which is of the order of 1/100-1/10000.
Several scores of annual discharge m a x i m a measured during the period of hydrometric observations o n a river are insufficient to characterize the frequency of extremely high m a x i m a . It is necessary one w a y or another to enlarge the scope of observations o n which the judgment is based.
Distribution of river flow probabilities is assumed to be steady for decades of years (the influence of m a n ' s activity, if it is apparent and if it m a y be evaluated reliably should be taken into account).
Although different for each river basin, the distribution of river flow probabilities has s o m e properties c o m m o n to all river basins. T h e distribution function must include all positive values. There is n o reason to establish a m i n i m u m of annual m a x i m u m discharge other than zero. There is also n o reason to restrict the upper limit of the distribution function as the lower the probability, the greater the discharge.
Functions satisfying the stated conditions are obviously fixed by three given independent parameters. T h e mathematical expression of the parameters m a y vary, but they can be reduced to the standard parameters: the m e a n or center of distribution, the standard deviation and the coefficient of skew or asymmetry. (See also [1]).
A n u m b e r of distribution functions such as the gamma-distribution, the curves of A . Fischer-Slade (the lognormal distribution), G u m b e l ' s curves, etc. are used in hydro- logical calculations. G u m b e l ' s functions are of interest as a n attempt to plot a distribution of extreme values; such an attempt to base a distribution theoretically seems to be applicable in m a n y branches of science. But application of G u m b e l ' s distribution to m a x i m u m river discharges is grounded stochastically n o m o r e than the use of other distribution functions. Discharges of various days of the year are not statistically uniform and are also intercorrelated. T h e criterion of suitability of any type of distribution is its agreement with frequencies observed in practice.
In the U S S R the three parameter gamma-distribution has become widely applied.
The curves of this family comply with all the above mentioned conditions and describe the observed frequency of high water satisfactorily in most of the cases studied. They are introduced in standards for evaluation of m a x i m u m discharges in the U S S R .
The distribution function is expressed by the equation
d x V riy) x„lb/r(y)J\xJ { V / X v ) xj J where
x the studied varíate (in our case it is the m a x i m u m discharge for a year);
y the density of probabilities;
p the probability of exceedence of x;
x0 the center of distribution (mean value of x) ;
y and b parameters, connected by transcendental equations with standard parameters of coefficients of variation Cv and stew (asymmetry) Cs ;
r the symbol of the gamma-function.
The assumption of the family [2, 3, 4] is that some function xb of the variable under study follows the gamma-distribution. A t b = 1 equation (1) is of this type. Tables 5 and 6 have been worked out to plot curves of this distribution within a broad range of values of coefficients of variation and of skew.
Besides the g a m m a distribution the Weibull-Goodrich, the exponential one /2, and some others are particular cases of equation (1 ). The same family of distribution functions was published in 1962 [7]. O f course some other kinds of distribution curves are possible to meet the required conditions. O n e can suppose, however, that different variants of curves with equal x0, Ct„ Cs and embracing the interval 0 ^ x < co are in practice very similar, no matter h o w different their mathematical expressions.
The errors in estimation of probable runoff values are due to accidental errors caused by non-representativeness of the run-off data used and due to the systematical deviations resulting from incomplete conformity of the assumed distribution probabilities with correlations observed in nature.
Standard error of estimation of discharges of the given exceedence probability characterizes accidental errors by curves the parameters of which are estimated from observations for n years:
Ep = ^ /i+i±^fr'
2(2)
Jn V 2/c
2here
k' = dk/dCv the derivative of the ratio k = xp/x0, by the coefficient of variation C„ of the estimated values ;
xp the value corresponding to the probability of exceedence p ; x0 m e a n value of x.
The derivative k' is evaluated from tables of the gamma-distribution curves for values of C„, corresponding to the river under consideration. Formula (2) m a y be applied to distributions close to the gamma-distribution [8].
Systematic bias in evaluation of the m a x i m u m flow m a y be revealed by means of a method proposed in the U S S R . This allows a check o n the discrepancy between the observed and estimated frequencies of the m a x i m u m m a x i m o r u m discharges if not for each individual river then at least for a group of hydrologically similar basins.
Let us assume that independent flow records, each for n years, are available for a set of basins. M a x i m u m m a x i m o r u m values are to be selected from each record. If frequency
