/ The Extremes
of the Extremes: Extraordinary Floods
edited by Árni Snorasson, Helga P. Finnsdóttir & Marshall E. Moss
IAHS Publication no. 271 (published March 2002) intheIAHSSeriesofProceedingsandReportsISBN 1-901502-66-X; 394 + xiv pp.; price £60.00
Extreme floods are among the most destructive forces of nature; there is a perception that they are occurring with higher frequency now than in the past. This is a cause for international concern and calls for an understanding of the circumstances that might generate such disastrous events.
This was the motive for the Reykjavík symposium on extraordinary floods, the Extremes of the Extremes, co-convened by the International Association of Hydrological Sciences (IAHS) and the Hydrological Service in Iceland; this publication is an outcome of that meeting.
The main focus of the papers included in this volume is the geophysical processes related to floods, but the statistical and mathematical aspects of flood analysis and forecasting are also addressed, and the issues of flooding and flood abatement are put into economic, social and ethical perspective. The 60 papers in this volume have been grouped under the following themes:
– Physical processes related to floods interplay of snow and ice with rain and temperature— intense mountain precipitation in semiarid areas—glacial outburst floods—volcanic activity and the flood at Vatnajökull Glacier, Iceland, 1996
– Prehistoric and historic floods catastrophic floods in Iceland—floods during the North American glaciation—extreme floods on Mars
– Floods: case studies from around the world, from the Himalayas to the Mediterranean to Norway
– Geomorphological and environmental questions related to floods focusing on glacial floods
– Statistical analysis and forecasting of floods extreme value analysis—multivariate considerations—forecasting: theoretical and methodological viewpoints—practicalities of forecasting and flood zone mapping—climate variability and change
– Predictability and abatement of floods the fundamental nature of extreme events—how society does and should deal with the threat of flood hazards
Contents
1 /
Physical Processes Related to Floods
Facing a changeable hydrological regime in a Mediterranean country GiuseppeBatini & Marcello Benedini /3
Extreme ice jam floods along the Saint John River, New Brunswick, Canada Spyros Beltaos & Brian C. Burrell /
9
Maximum rainfall in Poland—a design approach Ewa Bogdanowicz & JuliuszStachý /
15
Catastrophic flooding in the Czech Republic since 5 July 1997 Alois Chlebek & Milan Jařabáč /
19
Influence of climate on the flood frequency distribution within a large region of southern Italy Pierluigi Claps, Mauro Fiorentino & Vito Iacobellis /
25
Assessment of possible jökulhlaups from Lake Demmevatn in Norway
Hallgeir Elvehøy, Rune V. Engeset, LissM.Andreassen, Jack Kohler, YngvarGjessing & Helgi Björnsson /
31
Simulation of the jökulhlaup on Skeiðarársandur, Iceland, in November 1996 using MIKE 21 HD Claes Eskilsson, Jón Ingvi Árnason & Dan Rosbjerg /
37
The estimation of rainfall frequency in a Mediterranean environment due to extraordinary combinations of hydrological and climatic conditions SalvatoreGabriele & Paolo Villani /
45
Multifractal taming of extreme hydrometeorological events Pierre Hubert, Hocine Bendjoudi, Daniel Schertzer & Shaun Lovejoy /
51
The initiation of the 1996 jökulhlaup from Lake Grímsvötn, Vatnajökull, Iceland (Keynote paper) Tómas Jóhannesson /
57
How often do extreme events occur? Felix Naef / 65
Controls on the development of supraglacial floodwater outlets during jökulhlaups Matthew J. Roberts, Andrew J. Russell, Fiona S. Tweed &
Óskar Knudsen /
71
Extreme floods in mountain areas—an overview (Keynote paper) ManfredSpreafico /
77
A hydroclimatic analysis of the 1997 flood at Grand Forks, North Dakota (USA) Paul E. Todhunter /
87
Flood prediction in permeable drainage basins Ana Lisa Vetere Arellano, PaulSamuels & Paul Webster /
93
2 / Prehistoric and Historic Floods
Recent extreme floods on Mars Devon Burr & Alfred McEwen / 101
Jökulhlaup deposits at the Ásbyrgi Canyon, northern Iceland: sedimentology and implications for flow type Óskar Knudsen & Andrew J. Russell /
107
Evidence for province-wide water storage and catastrophic drainage beneath the Laurentide Ice Sheet, Alberta, Canada Mandy J. Munro-Stasiuk & DarrenB.Sjogren /
113
Catastrophic floods in Iceland Haukur Tómasson / 121
3 / Floods: Case Studies
The most severe floods of the Tiber River in Rome MariaGabriellaAlessandroni & Gianrenzo Remedia /
129
Extraordinary summer flood in a karst area: casestudy in Croatia BorisBerakovic & Ksenija Cesarec /
133
Recent extreme weather events in the Nepal Himalayas (Keynote paper) SureshRaj Chalise & Narendra Raj Khanal
/141
The flood of floods—Poland, summer 1997 Zbigniew W. Kundzewicz / 147
Historic extreme floods as input to dam safety analyses Grethe Holm Midttømme & Jens Kristian Tingvold /
155
A study of extreme storm events in the Greater Athens area, Greece MariaMimikou, Evangelos Baltas & EkateriniVaranou /
161
Highest floods in India P. R. Rakhecha / 167
The large flood of 1860 in Norway Lars Andreas Roald / 173
A stochastic model for exploring extreme flood events in the UK HarveyJ.E.Rodda, Agnete Berger & RobertMuirWood /
179
4 / Geomorphological and Environmental Questions Related to Floods
Relative roles of geomorphology and water input distribution in an extreme flood structure Christophe Cudennec, Frederic Gogien, Jacques Bourges, JeanDuchesne & Ridha Kallel /
187
Surge-related floods at Skeiðarárjökull Glacier, Iceland: implications for ice-marginal outwash deposits Thaiënne A. G. P. Van Dijk & Oddur Sigurðsson /
193
Real-time monitoring of glacial rivers in Iceland Sverrir Óskar Elefsen, ÁrniSnorrason, Hreinn Haraldsson, Sigurður Reynir Gíslason & HrefnaKristmannsdóttir /
199
Formation of kettle holes following a glacial outburst flood (jökulhlaup), Skeiðarársandur, southern Iceland Helen Fay /
205
Characterizing the flash flood hazards potential along the Red Sea coast of Egypt Eman M. Ghoneim, Nigel W. Arnell & GilesM.Foody /
211
Erosion and deposition in the proglacial zone: the 1996 jökulhlaup on Skeiðarársandur, southeast Iceland Basil Gomez, Andrew J. Russell, LaurenceC.Smith & Óskar Knudsen /
217
Seasonal variation in the chemistry of glacial-fed rivers in Iceland HrefnaKristmannsdóttir, Sigurður R. Gíslason, Árni Snorrason, HreinnHaraldsson, Steinunn Hauksdóttir & Ásgeir Gunnarsson /
223
Geochemical warning for subglacial eruptions—background and history
Hrefna Kristmannsdóttir, Árni Snorrason, Sigurður R. Gíslason, HreinnHaraldsson, Ásgeir Gunnarsson, Steinunn Hauksdóttir & SverrirÓ.Elefsen /
231
Criteria for distinguishing high magnitude flood events in the proglacial fluvial sedimentary record Philip M. Marren /
237
The influence of channel flood history on the impact of the November 1996 jökulhlaup, Skeiðarársandur, Iceland (Keynote paper) Andrew J. Russell & Óskar Knudsen /
243
Impact of the July 1999 jökulhlaup on the proximal River Jökulsá á Sólheimasandi, Mýrdalsjökull Glacier, southern Iceland Andrew J. Russell, Fiona S. Tweed, Óskar Knudsen, Matthew J. Roberts, Timothy D. Harris & Philip M. Marren /
249
5 /
Statistical Analysis of Floods
Dam design flood estimation based on bivariate extreme-value distributions Álvaro A. Aldama & Aldo I. Ramírez /257
Study of parameter estimation methods for Pearson-III distribution in flood frequency analysis Chen Yuanfang, Hou Yu, Pieter Van Gelder & Sha Zhigui /
263
Assessment of a simplified runoff model for theoretical derivation of the probability distribution of floods Giuseppe Gioia, Vito Iacobellis & MariaRosaria Margiotta /
271
Power law distribution of catastrophic floods Carlo De Michele, PaoloLaBarbera & Renzo Rosso /
277
The probable maximum flood at the Ukai and Lakhwar dam sites in India P.R.Rakhecha & C. Clark /
283
Estimation of extreme Pareto quantiles using upper order statistics (Keynote paper) ÓliG.B.Sveinsson, Duane C. Boes & Jose D. Salas /
289
A study on threshold selection in POT analysis of extreme floods ShigenobuTanaka & Kaoru Takara /
299
6 /
Statistical Analysis and Forecasting
Water level forecasts for Lake Managua Kari Ahti & Luis Sandor Palacios Ruiz / 307Flood inundation maps—mapping of flood prone areas in Norway Hallvard Berg / 313
Application of the stochastic self-training procedure for the modelling of extreme floods Vadim Kuzmin, Pieter van Gelder, Hafzullah Aksoy & ISmail Kucuk /
317
The region of influence approach in complex and highly variable environments—experiences from Switzerland Martin Pfaundler & Paolo Burlando /
323
Extreme climatic and hydrological events associated with El Niño/Southern Oscillation: analysis (1500–1999) and forecast (2000–2050)
JorgeSánchez-Sesma /
329
Weighted least squares method—improved estimates when the index flood method is used with annual maximum floods (Keynote paper) Savithri Senaratne & ConlethCunnane /
333
Simulation of discharge fields Thomas Skaugen / 341
Flood forecasting for the River Rhine in TheNetherlands Eric Sprokkereef / 347
7
/The Predictability and Abatement of Floods
The world’s maximum observed floods Reg Herschy / 355Flood protection in the context of sustainable development ZbigniewW.Kundzewicz /
361
What is an extreme flood and for whom? Dan Lundquist / 367
Extremeness of extreme floods Ferenc Papp / 373
Coping with extreme floods: warnings, impacts and response
Edmund Penning-Rowsell & Sue Tapsell /
379
Social and economic dimensions of the 1998 extreme floods in coastal Chiapas, Mexico Alvaro Sanchez-Crispin & Enrique Propin-Frejomil /
385
Key word index / 391
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The Extremes of the Extremes: Extraordinary Floods (Proceedings of a symposium held at Reykjavik, Iceland, July2000). IAHS Publ. no. 271, 2002.
pp. 3–8.
Facing a changeable hydrological regime in a Mediterranean country
GIUSEPPE BATINI & MARCELLO BENEDINI
Department of Technical Services, Via Curtatone 3, I-00185 Rome, Italy
e-mail:
Abstract Located completely within the Mediterranean basin, Italy is now facing a climatic pattern characterized by new trends. The occurrence of floods seems in particular to be more worrisome than in past years, with higher peak values and a decreased frequency. At the same time, long periods of scarce rainfall seem to favour the occurrence of droughts, which create difficulties in water resources management. The Italian Department of Technical Services, in line with its mandatory countrywide activity, has promoted ad hoc investigations to improve and update knowledge of the fundamental mechanisms governing the high precipitation and flood regime. A substantial part of the Department’s activity is in hydrological surveys for which a monitoring system, based on the most advanced technological breakthroughs, has been put into operation.
Key words Mediterranean; monitoring; flood frequency; drought; precipitation characteristics
______
The Extremes of the Extremes: Extraordinary Floods (Proceedings of a symposium held at Reykjavik, Iceland, July2000). IAHS Publ. no. 271, 2002.
pp. 9–14.
Extreme ice jam floods along the Saint John River, New Brunswick, Canada
SPYROS BELTAOS
National Water Research Institute, PO Box 5050, 867 Lakeshore Road, Burlington, OntarioL7R 4A6, Canada
e-mail:
BRIAN C. BURRELL
New Brunswick Department of the Environment, Fredericton, New Brunswick, Canada
Abstract Extreme ice jams and the resulting floods and ice runs destroy property and infrastructure, disrupt transportation, inhibit hydropower generation, affect aquatic life and habitat, and pose risks to human life. Ice jam processes are described briefly and their flooding potential explained in terms of their large aggregate thickness and roughness. The recent flood history of the Saint John River shows that the five most severe flood events during the period 1958–1999 were caused by ice jams resulting from the spring breakup of the ice cover. This is reflected in the relative frequencies of ice-jam and open-water stages, especially in the range of rare events. At present, efforts are underway to implement predictive models in flood forecasting and emergency response operations. Prompted by global warming concerns, historical hydroclimatic records have been analysed. The available evidence suggests the Saint John River is becoming subject to more frequent mid-winter jams and higher April flows, both of which augment the potential for major jamming.
Key words breakup; extreme event; flood; frequency; global warming; ice jam; return period; river; water level
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The Extremes of the Extremes: Extraordinary Floods (Proceedings of a symposium held at Reykjavik, Iceland, July2000). IAHS Publ. no. 271, 2002.
pp. 15–18.
Maximum rainfall in Poland—a design approach
EWA BOGDANOWICZ & JULIUSZ STACHÝ
Institute of Meteorology and Water Management, Podlesna 61, 01-673 Warsaw, Poland
e-mail:
Abstract Heavy rainfall data are often used in engineering design of structures that control storm runoff. Series of annual maximum precipitation (1960–1990) in 14 fixed time intervals from 20 meteorological stations in Poland were used to develop a general relationship for rainfall depth, duration and frequency. Generalization of rainfall information was done by means of regional description. The regions were distinguished by using cluster analysis.
Key words mmaximum rainfall; statistics; cluster analysis
______
The Extremes of the Extremes: Extraordinary Floods (Proceedings of a symposium held at Reykjavik, Iceland, July2000). IAHS Publ. no. 271, 2002.
pp. 19–23.
Catastrophic flooding in the Czech Republic since 5 July 1997
ALOIS CHLEBEK & MILAN JAŘABÁČ
Forestry and Game Management Research Institute, Nadrazni 2811, 73-801FrýdekMístek, Czech Republic
e-mail:
Abstract The Czech Republic is not often affected by natural catastrophes like floods which may be caused either by sudden rainstorms or by less intense but prolonged rainfall. Both types of floods may be associated with torrential outflows in headwaters and accelerated erosion of streambeds and banks. Such an event was experienced at the beginning of July 1997. There are an increasing number of insurance claims on the security of lives and properties. Flood defence must consist not only of engineering structures, but also the public and the state authorities must be prepared to defend themselves.
Key words forest hydrology; experimental basins; catastrophic flood; flood defence
______
The Extremes of the Extremes: Extraordinary Floods (Proceedings of a symposium held at Reykjavik, Iceland, July2000). IAHS Publ. no. 271, 2002.
pp. 25–30.
Influence of climate on the flood frequency distribution within a large region of southern Italy
PIERLUIGI CLAPS, MAURO FIORENTINO
Dipartimento di Ingegneria e Fisica dell’Ambiente, Università della Basilicata, Contrada Macchia Romana, I-85100 Potenza, Italy
e-mail:
VITO IACOBELLIS
Dipartimento di Ingegneria delle Acque, Politecnico di Bari, via E. Orabona 4, I-70125 Bari, Italy
e-mail:
Abstract In the theoretical derivation of flood frequency distribution as well as in the statistical regional analysis, climate plays a decisive role, being closely related to values and to patterns of variability of physically consistent parameters. We focused on the average annual number of flood peaks, Lq, and on the ratio of Lq over the average annual rate of rainfall events, Lp, as crucial parameters of extreme value distributions based on a Poisson process of occurrences. The link between climate and these statistical parameters is first empirically analysed and then explained as to how they relate to a characteristic water loss parameter dependent on climate, namely, a dimensionless loss factor f* representing the storm rainfall threshold that determines if runoff is generated or not. Data from 20 basins in southern Italy, with hyper-humid to semiarid climates, show meaningful relationships between the degree of aridity and estimates of Lq/Lp and f*.