The Use of Historical Data in Natural Hazard Assessments

Advances in Natural and Technological Hazards Research

VOLUME 17

EDITORIAL BOARD

Wang Ang-Sheng, Chinese Academy of Sciences, Institute of Atmospheric Physics, Beijing, P.R. China

Gerhard Berz, Munchener Ruckversicherungs-Gesellschaft, Munchen, Germany

Oscar Gonzalez-Ferran, Departamento de Geologia y Geofisica, Facultad de Ciencias Fisicas y Mathematicas, Universidad De Chile, Santiago, Chile

Cinna Lomnitz, National University of Mexico, Instituto de Geofisica, Mexico, D. F. Mexico

Tad S. Murty, Baird & Associates, Ottawa, Ontario, Canada

Alvin H. Mushkatel, Office of Hazards Studies, Center for Public Affairs, Arizona State University, Tempe, AZ, USA

Joanne M. Nigg, Disaster Research Center, University of Delaware, Newark, DE, USA

Alexei V. Nikolaev, Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia

Paul M. Thompson, Flood Hazard Research Center, Middlesex University, Enfield, UK

Donald A. Wilhite, International Drought Information Center, University of Nebraska, Lincoln, NE, USA

The titles published in this series are listed at the end of this volume.

The Use of Historical Data in Natural Hazard Assessments

Edited by

THOMAS GLADE Department of Geography, University of Bonn, Germany

PAOLA ALBINI Instituto Nazionale di Geofisica e Vulcanologia, Sezione di Milano, Milano, Italy

and

FELIX FRANCES Departamento de Ingenierfa Hidraulica y Medio Ambiente, Universidad Politecnica de Valencia, Spain

SPRINGER-SCIENCE+BUSINESS MEDIA, B.v.

А C.I.P. Catalogue гecoгd loг this book is availabIe lгom the Libгaгy 01 Congгess.

Printed оп acid-free рарег

AII Rights Reseгved © 2001 Spгingeг Science+Business Media Doгdгecht Oгiginally pubIished Ьу Kluweг Academic PubIisheгs in 2001 Softcoveг гepгint 01 the haгdcoveг 1з! edition 2001 No раг! 01 the mateгial pгotected Ьу this copyгight notice тау Ье гepгoduced ог utilized in апу loгm ог Ьу апу means, electгonic ог mechanical, including photocopying, гecoгding ог Ьу апу inloгmation stoгage and гetгieval system, without wгitten peгmission Iгom the copyгight owneг

ISBN 978-90-481-5762-4 ISBN 978-94-017-3490-5 (eBook)DOI 10.1007/978-94-017-3490-5

"When we study history, we obtain a more profound insight into human nature, by instituting a comparison between the present and the former states of society. We trace the long series of events which have gradually led to the actual posture of affairs [ ... ] As the present conditions of nations is the result of many antecedent changes, some extremely remote and others recent, some gradual, some others sudden and violent, so the state of the natural world is the result of a long succession of events; and if we would enlarge our experience of the present economy of nature, we must investigate the effects of her operations in former epochs."

Charles Lyell, 1830. Principles of Geology. 1st edition, 3 vols, London, vol. I, p. 2.

v

TABLE OF CONTENTS

List of Contributors IX

Preface XIV

T. Glade, P. Albini and F. Frances An Introduction to the use of historical data in natural hazard assessments XVII

PART A: Earthquakes (Albini, P.)

F. Galadini, P. Galli, D. Molin and G. Ciurletti Searching for the source of the 1117 earthquake in northern Italy: A multidisciplinary approach 3

J. Vogt Sismicite historique des petites Antilles. Un test pour quelques annees du milieu du XIX· siecle 29

P. Albini and F. Rodriguez De La Torre The 1828-1829 earthquake sequence in the provinces of Alicante and Murcia (S-E Spain): Historical sources and macroseismic intensity assessment 35

MS. Barbano, R. Rigano and I Coppolino The seismic history of Nicolosi (Catania, Italy) 55

T. Susagna, X Goula, and A. Roca A new macroseismic catalogue for Catalonia 71

M Mucciarelli and M Stucchi Expeditious seismic damage scenarios based on intensity data from historical earthquakes 81

PART B: Flooding (Frances, F.)

F. Frances Incorporating non-systematic information to flood frequency analysis using the maximum likelihood estimation method

M Fernandez De Villalta, G. Benito and A. Diez-Herrero

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Historical flood data analysis using a GIS: The Palaeotagus database 101

R. Naulet, M Lang, D. Coeur and C. Gigon Collaboration between historians and hydrologists on the Ardeche river (France) 113

M -c. Llasat and M Barriendos Availability and potential of historical flood series in the Iberian Peninsula (14th - 20th centuries) 131

S. Pagliara Hydraulic modelling and historical inundation assessment for the Versilia river 141

PART C: Landslides (Glade, T.)

T. Glade Landslide hazard assessment and historical landslide data - an inseparable couple? 153

V. Rizzo, F. Fragale and 0. Terranova Widespread landslide and flood events in the Catanzaro's Isthmus (Calabria, Italy); Relationships with rainfall data 169

C. Alger and E.E. Brabb The development and application of a historical bibliography to assess landslide hazard in the United States 185

D. Calcaterra and M Parise The contribution of historical information in the assessment of landslide hazard 201

Index 219

LIST OF CONTRIBUTORS

Albini, Paola Instituto di Ricerca sui Rischio Sismico, CNR Via E. Bassini 15 20133 Milano ITALY Tel + 39-02-23699264 Fax +39-02-26680987 Email: albini@irrs.mi.cnr.it

Alger, Christopher C.E.G., C.HG, LFR Levine Fricke 1900 Powell Street, 12th Floor Emeryville California 94608 USA Tel +01-510-5969683 Fax +01-510-6524906 Email: chris.alger@lfr.com

Barbano, Maria Serafina Dipartimento di Scienze Geologiche Universita di Catania Corso ltalia 55 95129 Catania ITALY Tel +39-95-7195729 Fax +39-95-7195712 Email: barbano@mbox.unict.it

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Barriendos, Mariano Departamento de Astronomia y Meteorologia Universidad de Barcelona Avda Diagonal 647 08028-Barcelona SPAIN Tel +34-934021124 Fax +34-934021133 Email: mbarri@retemail.es

Benito, Gerardo Centro de Ciencias Medioambientales Serrano 115 bis 28006 Madrid SPAIN Tel +34-91-745 2500 Fax +34-19-564 0800 Email: ebvaa75@ccmocsic.es

Brabb, Earl E. U. S. Geological Survey 345 Middlefield Road MS 975, Menlo Park CA 94025 USA Tel +01-650-3295140 Fax +01-650-3294936 Email: ebrabb@isdmnl.wr.usgs.gov

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Calcaterra, Domenico Dipartimento di Ingegneria Geotecnica Universita di Napoli "Federico II" via de Sangro di Sansevero, 4 80134 Napoli ITALY Tel +39-081-7682161 Fax +39-081-7682162 Email: domcalca@unina.it

Ciurletti, Gianni Provincia Autonoma di Trento Ufficio Beni Archeologici Castello Buonconsiglio 38100 Trento ITALY Tel +39-0461-233770 Fax +39-0461-232075

COlur, Denis Acthys-Diffusion 3 r. Irvoy 38 000 Grenoble FRANCE Tel + 33-476962485 Fax +33-476962485 Email: Denis. Coeur@wanadoofr

Coppolino, Irene Dipartimento di Scienze Geologiche Universita di Catania Corso Italia 55 95129 Catania ITALY

Diez-Herrero, Andres Universidad S.E.K. C/ Cardenal ZUiiiga 12 40003 Segovia SPAIN Tel +34-921-412410 Fax +34-921-445593 Email: andresdiez@Sekmail.com

Fernandez de Villa Ita, Marfa Instituto de Geologia Econ6mica Facultad de Ciencias Geol6gicas Universidad Complutense de Madrid 28040 Madrid SPAIN Tel +34-913944799 Fax +34-913944808 Email: mariaj@eucmos.sim.ucm

Fragale, Francesco CBR-IRPI Via L. Grassi 31 87030 Commenda di Rende (Cosenza) ITALY Tel +39-984-839132 Fax +39-984-837382 Email: ffragale@libero.it

Frances, Felix Dep. de Ingenieria Hidniulica y Medio Ambiente Universidad Politecnica de Valencia 46022 Valencia SPAIN Tel + 34-963-877612 Fax +34-963-877618 Email: ffrances@hma.upv.es

Galadini, Fabrizio lstituto di Ricerca sulla Tettonica Recente, CNR Area di Ricerca di Roma-Tor Vergata Via del Fosso del Cavaliere 00133 Roma ITALY Tel + 39-06-49934211 Fax +39-06-49934479 Email: galad@irtr.rm.cnr.it

Galli, Paolo Servizio Sismico Nazionale Ufficio Sismogenesi e Vulnerabilita' dell'Ambiente Fisico Via Curtatone 3 00185 Roma ITALY Tel +39-6-44442892 Fax +39-6-4466579 Email: paolo.galli@dstn.it

Gigon, Christine Direction Departamenta\es de I 'Equipement 1 avo Du Vanel BP 613 07006 Privas cedex FRANCE Tel + 33-47-6655069 Fax +33-47-5655006 Email: christine.gigon@equipement.gouvjr

Glade, Thomas Geografisches Institut Rheinische Friedrichs-Wilhelms­Universitat Meckenheimer Allee 166 53115 Bonn GERMANY Tel +49-228-739098 Fax +49-228-739099 Email: thomas@Slide.giub.uni-bonn.de

Goula, Xavier Institut Cartografic de Catalunya Parc de Montjuic, sin 08038 Barcelona SPAIN Tel +34-93-5671500 Fax +34-93-5671567 Email: xgoula@icc.es

Lang, Michel Cemagref, Division Hydrologie-Hydraulique 3 bis quai Chauveau 69336 Lyon cedex 09 FRANCE Tel +33-472208798 Fax +33-478477875 Email: michel.lang@cemagreffr

L1asat, Maria Carmen Departamento de Astronomia y Meteoro\ogia Universidad de Barcelona A venida Diagonal 647 08028 Barcelona SPAIN Tel +34-934021124 Fax +34-934021133 Email: carmell@am.ub.es

Molin, Diego Servizio Sismico Nazionale Via Curtatone 3 00184 Roma ITALY Tel +3906-44442891 Fax +39 06-4466579 Email: diego.molin@dstn.it

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Mucciarelli, Marco D.I.S.G.G. UniversitA della Basilicata Campus Macchia Romana 85100 Potenza ITALY Tel +39-0971-205094 Fax +39-0971-207050 Email: mueciarelli@unibas.it

Naulet, Robin Cemagref, Division Hydrologie-Hydraulique 3 bis quai Chauveau 69336 Lyon cedex 09 FRANCE Tel +33-47-2208798 Fax +33-47-8477875 Email: robin. naulet@eemagreffr

Pagliara, Stefano Dipartimento di Ingegneria Civile UniversitA di Pisa via Gabba22 56126 Pisa ITALY Tel +39-050550376 Fax +39-050830206 Email: s.pagliara@ing.unipi.it

Parise, Mario CNR-CERIST Istituto di Geologia Applicata e Geotecnica Via Orabona, 4 70125 Bari ITALY Tel +39-805-4281-37/-11 Fax +39-805-567944 Email: eerimp06@area.ba.enr.it

Rigano, Rosaria Dipartimento di Scienze Geologiche UniversitA di Catania Corso Italia 55 95129 Catania ITALY Tel +39-95-7195729 Fax +39-95-7195712 Email: riganor@mbox.uniet.it

Rizzo, Vincenzo CNR-IRPI Via Cavour 87030 Roges di Rende (CS) ITALY Tel +39-984-835514 Fax +39-984-835319 Email: rizzo@area.es.enr.it

Roca, Antoni Institut Cartografic de Catalunya Parc de Montjuic, sin 08038 Barcelona SPAIN Tel +34-93-5671500 Fax +34-93-5671567 Email: roea@iee.es

Rodriguez de la Torre, Fernando Calle Pez Austral 7/7°-B 28007 Madrid SPAIN Tel + 34-91-5746581 Fax +34-91-5746581

Stucchi, Massimiliano Istituto di Ricerca sul Rischio Sismico, CNR ViaE. Bassini 15 20133 Milano ITALY Tel +39-02-23699262 Fax +39-02-26680987 Email: stucchi@i"s.mi.cnr.it

Susagna, Teresa Institut Cartografic de Catalunya Parc de Montjuic, sin 08038 Barcelona SPAIN Tel +34-93-5671500 Fax +34-93-5671567 Email: tsusagna@icc.es

Terranova, Oreste CNR-IRPI Via Cavour 87030 Roges di Rende (CS) ITALY Tel +39-984-835514 Fax + 39-984-835319 Email: terranova@area.cs.cnr.it

Vogt, Jean Rue Dr. Woehrlin 1 67000 Strasbourg-Robertsau FRANCE Tel +33-38-8418970

Xlll

PREFACE

Natural hazards such as earthquakes, landslides, floods, volcanic eruptions, tsunamis, and hurricanes cause environmental, economic as well as sociological problems worldwide. In recent years, greater availability of information and sensational media reports of natural hazard occurrence - and in particular in terms of property damage or loss oflife caused by these hazards - resulted in an increase of hazard awareness at a societal level. This increase in public awareness has often been misconstrued as an indication that natural hazards have been occurring more frequently with higher magnitudes in recent years/decades, thus causing more damage than in the past. It is still under debate, however, to which extent recent increases in damage can be related to changing frequencies of natural processes, or whether catastrophic events occur at similar rates as they always had. If the latter is the case, the reason for a greater damage can be related to dramatic population growth over the last century, with a substantial augmentation of population density in some regions. Indeed, the implications are more server in underdeveloped and developing countries, where urbanisation has increasingly occurred in hazard prone areas such as coastal zones, alluvial river plains and steep slopes, thus causing an increase in the exposure to natural hazards. Some groups of society in wealthy countries accept higher risks in order to live directly on top of a cliff or on a steep slope to enjoy panoramic views of the landscape. However, there is a cost associated with this also, in the format of engineering and insurance.

Human interference with nature and the related socio-economic implications have led to more detailed analysis of several natural processes. Research aimed towards a better understanding of the individual natural processes has been developed by specific specialists such as seismologists, volcanologists and geophysicists, hydrologists, hydraulic engineers, oceanographers and coastal engineers, as well as by geologists, soil mechanics engineers and geomorphologists. Each discipline has studied actual process behaviour through extensive field investigations and tried to develop advanced process modelling techniques to understand the influence of specific factors on the overall process in more detail.

As a result of these studies, different approaches to natural hazard assessment have been developed, and different disciplines apply slightly different meanings to the key term natural hazard. In general, natural hazard is defined as the probability of occurrence of a potentially damaging natural process, of a specific magnitude, with a given recurrence interval, in a certain place. Consequently, an inherent demand in all approaches is that a comprehensive natural hazard assessment requires prediction of how often, when and ultimately where dangerous events are likely to occur. It has to establish process variability in space and time, and to appraise the impact on natural and socio-economic environments. In particular, to answer the question of "how often" and "when", it is essential to have a

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PREFACE xv

detailed set of data containing as much information as possible on past events. Thus, a reliable assessment of hazardous natural events and their effects requires sound and comprehensive inventories and databases.

Historical data appear to be particularly important for frequency/magnitude analyses, useful to both scientists and economists, as well as for defining the spatial and temporal occurrence of catastrophic events. In working with historical data, various issues have to be addressed independently of investigated phenomena:

Strategy related to rmding, collecting and storing of reliable historical records. This includes:

the identification of different typologies of historical sources through centuries, the consideration of the various types of methodologies and techniques applied in different research studies,

- the establishment of a scheme for reporting and summarising the data, and the implementation of a data base for the management of relevant data and its distribution to end-users.

Validation of collected data. Of specific interest is hereby consideration of the contrast between available and desirable information, and evaluation of the completeness and accuracy of records.

Interpretation of the information supplied by historical data with the aim of satisfying the main research, environmental, and economic issues.

In recognition of the importance of these issues, a conference session (The Use of Historical Data in Natural Hazard Assessments) was organised to summarise current use of historical databases in research relating to different natural hazard processes. This session was embedded within the Natural Hazard and Hydrological Science Symposium of the XXIVth General Assembly of the European Geophysical Society (EGS). The conference was held in The Hague, The Netherlands from 19th to 23rd April 1999. The session was divided into three sub-sessions and focussed on (a) earthquakes, (b) floods, and (c) landslides; this volume is structured accordingly. Within each part, contributions dealing with each phenomenon are compiled in order to provide an overview of the use of historical data in each field. This book brings together 16 of the 50 selected contributions to the sessions.

Each selected contribution addresses one or more of the research topics summarised above and relates it to specific case histories in the field of earthquakes, floods and landslides. Unfortunately, some issues are not covered to the same extent and in as much detail as others. Despite this lack, we are confident that this book will provide an overview of the use of historical data in natural hazard assessment, with all its inherent limitations as well as its strengths, and that it will prompt research towards future projects aiming to include more extensively historical data in the analysis. We specifically want to encourage these research projects because we believe that historical data will increase the accuracy of any occurrence probability dramatically and hence, it will result in more reliable natural hazard assessments.

This book is of interest to researchers working in the field of natural hazard assessment including those from disciplines such as seismology, vu1canology, engineering geology,

xvi PREFACE

geomorphology as well as hydrological, geotechnical and environmental engineering, to name a few only. Institutions with involvement in natural hazards research and/or assessment range from universities and governmental agencies to private consultants. It is our belief that it is beneficial for all these groups to use historical data in natural hazard assessments. Suggestions for applications are given by the papers in these Proceedings.

Besides the organisers of the EGS conference, who made the sessions possible, we would like to thank in particular the session co-conveners Nick Ambraseys, Michel Lang and Fausto Guzzetti for their support in organising and carrying out the session. Numerous referees helped through their suggestions and comments to ensure the quality of individual papers. And fmally, we would like to thank the staff of Kluwer Scientific Publishers, in particular Petra van Steenbergen, for all their help and support during the preparation of this book.

Thomas Glade Bonn, Germany

Paola Albini Milano, Italy

Felix Frances Valencia, Spain

January, 2001

AN INTRODUCTION TO THE USE OF mSTORICAL DATA IN NATURAL HAZARD ASSESSMENTS

Abstract

T.GLADE Dep. of Geography, University of Bonn Meckenheimer Allee 166,53115 Bonn, Germany

P. ALBINI Istituto di Ricerca sui Rischio Sismico, CNR Via E. Bassini 15, 20133 Milano, Italy

F.FRANCES Dep. de Ingenieria Hidraulica y Medio Ambiente, Universidad Politecnica de Valencia, 46022 Valencia, Spain

Data supplied by historical sources are a basic element for natural hazard assessments and are highlighted with respect to rate of occurrence, duration of process and spatial extent. A review is proposed on how historical records of earthquakes, floods and landslides are being collected and used and how they can contribute in assessing the hazard relative to each phenomenon. Different approaches in the various disciplines are introduced and compared. Results indicate that same types of data are used differently within respective disciplines thus demonstrating the need of joint efforts to improve the access to and the availability of historical data, in particular for natural hazard assessments.

1. Introduction

Natural hazards have a significant impact on our environment, society as well as economy. Consequently, research on natural hazards has a long history focusing in particular on the process behaviour itself. Significant consequences due to natural hazard are induced by short-term processes (seconds to minutes) of lightnings, earthquakes and landslides, mid-term processes (hours to days) such as floods, hurricanes, storms, fIres, and volcanoes or long lasting processes (days to years) such as soil erosion, desertification, or droughts. Also spatial extent varies greatly. While lightnings or landslides occur on single locations only, earthquakes, fIres, hurricanes, volcanic eruptions or floods affect larger areas. In case of droughts or desertification, large regions are affected. Thus each process has to be studied according to different temporal and spatial scales.

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xviii T. GLADE, P. ALBINI AND F. FRANCES

Having natural disasters been recognised as "a threat to human life and development", the United Nations designed the period 1990-1999 as the International Decade of International Disaster Reduction (UNIIDNDR, res. 42/169/1987). In this framework numerous international projects have been launched and were focused on improving the approaches and techniques used to assess hazard related with natural disasters.

Traditionally, the particular natural hazard is examined by the respective discipline, which has developed its own research strategy and methodology to carry out the investigation (e.g. McGuire, 1993; Trimble 1998). This rises various issues. One consequent problem is, that the different disciplines are using the same sources but in different ways. In addition, same sources or similar methods have discipline-dependent terms, which vary greatly despite a similar meaning. In contrast, same terms might have different definitions in each discipline. All these problems cannot be solved within this contribution, nor can they be solved in the near future. However, it seems appropriate for this publication to defme the basic expression natural hazard before using it in the following as the common term.

In general, natural hazards are defined as the 'Probability of occurrence of a potential damaging natural process within a given period and a given region' (Varnes 1984; McGuire, 1993). The definition makes it obvious, that a natural process becomes a natural hazard only when humans or human capitaVmonetary asset is exposed to the respective process and might suffer from its consequences. Within this definition the probability of occurrence is also required. The most common type of deriving the probability is through process measurements. Examples are for floods stage heights, for earthquakes seismicity rates, for landslides movement rates, for droughts rainfall and so forth. The problem of the probability calculated from these actual measurements is obvious: they cover the measured period only. In order to get low magnitudelhigh frequency events as well as high magnitude/low frequency events, which are rarely measured within short measurement periods, it is necessary to include further sources of data previous to the period of systematic, instrumental recording. One of these sources are historical data. In this context, historical is defmed as the period, where human recorded information on specific events is available. This information is included in written and iconographic sources, that offer whatever evidence has been on purpose left to describe the effects of a natural disaster, from a letter to a friend to a scientific report. The intrinsic value of these sources has been independently recognised by different disciplines (e.g. Hooke and Kain, 1982; Ambraseys, 1983; Stedinger and Cohn, 1986).

Other specific methods of delineating non-systematic information of past occurrences of natural process include pollen analysis, Radio Carbon dating, dendrochronology, lichenometry, tephra and sediment stratigraphy, archaeological artifacts, to name a few only. However, the latter methods are not defmed as 'historical' data and are thus not considered within this book.

The previous paragraphs demonstrate the wide range of possibilities of using historical data for building up a chronology of natural process. It is evident, that these type of data are used in each discipline according to different methods. From the point of view of the hazard posed by earthquakes, floods and landslides, the use of historical data in natural hazard assessment is reviewed and set into perspective in this issue of 'Advances in Technological and Natural Hazard Research'.

INTRODUCTION TO THE USE OF HISTORICAL DATA xix

This book demonstrates through various case studies the varieties and possibilities of assessing and analysing historical data and how to apply and implement these sources to natural hazard assessments. The papers are organised in three parts according to the underlying process: earthquakes, floods and landslides. In the following, the respective papers within each part are discussed briefly within the context of their contribution to natural hazard assessments.

2. Seismic Hazard Assessment

Historical records of earthquakes have been recognised as one of the main ingredients for the assessment of seismic hazard, in the Global Seismic Hazard Assessment Program (GSHAP) - 1992-1999 (Giardini and Basham, 1993; Guidoboni and Stucchi, 1993). The method preferably employed in Europe and world wide to assess seismic hazard is the probabilistic one, supplying a probabilistic measure of ground shaking associated to earthquake recurrence in a period of 475 years. Thus, the importance of extending as far back in time as possible the series of infonnation on seismic activity has led to an increasing quantity, quality and reliability of historical methods and records collected and used in Europe and throughout the world in the last twenty years (Ambraseys, Vogt).

Parametric earthquake catalogues and databases have been implemented (e.g.: Boschi et al., 1997; Levret et aI., 1996; US Earthquake Intensity Database, NGDCINOOA); they supply mostly data already interpreted in a seismological perspective, that is the parameters of the seismic events only or associated with macroseismic intensity data points. Together with an evaluation of their "incompleteness" in time and space distribution, these fonnalised data are used to assess seismic hazard, though they represent just the distillation of the wealth of infonnation, on the earthquake both as a natural phenomenon and as a disaster with serious social impact, which is contained in the historical sources and records.

If new perspectives are being considered towards different approaches in assessing seismic hazard (see paragraph 5 of this introduction), the same applies for new suggestions on how the "original" records historical sources could be emphasised to further extend their contribution to hazard assessment methods.

In proposing the session on earthquakes, of which Part A of this volume presents the results, authors have been asked to focus their contributions on previous achievements and on discussing whether and how end-users could benefit of a different processing and more direct use of historical data on earthquakes.

Combining different disciplines such as palaeoseismology, archaeology and historical seismology, Galadini et al. propose to associate the destructive 1117 earthquake in Northern Italy to a seismogenic system located east of Verona. The discussion of this case history highlights the contribution of each set of independent data, from the geological to the historical records, towards a better definition of the seismogenic source which originated the event.

After numerous papers produced in the past thirty years on the seismicity of the Euro-Mediterranean area, Jean Vogt has chosen the case of the Lesser Antilles to demonstrate how a systematic investigation of the historical records of an area can

xx T. GLADE, P. ALBINI AND F. FRANCES

significantly improve the completeness and the reliability of the earthquake catalogues today available for seismic hazard assessment.

The earthquake sequence of 1828-1829 in Southeastern Spain was chosen by Albini and Rodriguez de la Torre as a case history to present the full process of historical investigation of a seismic sequence, from the collection of the sources coeval to the earthquake to their interpretation in terms of the new European Macroseismic Scale 98. The result is a homogeneous set of intensity data points which can be used for a more stable evaluation of the earthquake parameters.

Barbano et al. focus on the place of Nicolosi (Catania, Italy) to detail on the earthquake effects it experienced through the last five centuries. The seismic history of this place, destroyed three times and seriously damaged many other times, is delineated by means of the information supplied by historical records. The site catalogue obtained has then been processed to compute on a probabilistic basis the hazard at the site. The wealthy descriptions found in the sources for the 20111 century earthquakes have resulted also in three damage scenarios.

Susagna et al. report on the state-of-the-art of macroseismic studies in Catalonia (Spain). They describe how data have been col1ected and interpreted for earthquakes which have affected Catalonia since the 12111 century to today. The catalogue shows a recent approach to the description of past seismicity, as it supplies not only earthquake parameters but remarks on the quality of the data sets upon which they rely, and a series of maps of effects distribution as well.

Mucciarelli and Stucchi describe a new method to produce a seismic damage scenario by making use of macroseismic intensity data of past earthquakes. The technique they propose implies to simply superimpose the information on damage contained in the macroseismic database for Italian damaging earthquakes to a map showing today demographic and insediative distribution. The discussion concern three Italian cases (Garfagnana, 1920; Asolo, 1695; Cagli, 1781) and explain pros and cons of this method.

Far from being considered exhaustive, this set of contributions is anyway widely representative at least of two aspects strictly related with seismic hazard assessment. On the one hand, they show recent achievements of historical seismology both in improving its methodology to interpret the primary sources on earthquakes and in supplying end­users of increasingly reliable sets of macroseismic intensity data. On the other hand, they suggest that new approaches (e.g. Giardini, 1999; Gasperini et al., 1999)for making fully available in seismic hazard assessment these robust data are in the process of being experimented with encouraging results.

3. River Flood Hazard Assessment

River floods result from heavy rainfall or/and fast snowmelt events which produce an increase of the river hydrograph. These floods are a natural hazard, but only when affect humans or human properties are considered as a significant episode as it was defined previously. This human threshold for flood perception can change along time, but always can be related with the natural or artificial drainage capacity of the area.

Catastrophic floods have occurred along the history with a high social and economic impact. Just to give one example, the city of Valencia, on the Mediterranean coast of

INTRODUCTION TO THE USE OF HISTORICAL DATA xxi

Spain. has been flooded 22 times from the XIII century to nowadays. Despite large investments in structural flood protection measures in developed countries, also in recent years catastrophic floods continue happening: with an enormous economic impact as the Rhine floods in 1993 and 1995, or flash-flood with a high number of deaths as in Vaison-La-Romain (France) in 1992 with 42 casualties or in Biescas (Spain) in 1996 with 87 deaths.

Because the implications with humans, Flood Hazard Assessment must be done with the maximum precision. And this is not the traditional situation. The usual length of the systematic flood record is approx. 50 years, with flow gauge stations installed after the II World War. In some special cases the flood data length can be 100 years, and in the case of daily precipitation, it is possible to find rain gauge stations with more than 100 years, starting in the XIX Century. But in any case, the use of the systematic information alone to estimate quantiles of high return period (500 years or more) will clearly produce estimates with a low reliability.

The best way to increase the flood quantile estimate reliability is to increase the amount of information used in the parameter estimation process. One way to do this is with the incorporation of historical information. In most cities with a long history, it is easy to find traces of historical inundations of the city for a period starting in the XVI Century, which means a 500 years information period. Even more, in some places in China there are flood information periods with 2 000 years length.

The first time historical information was used for Flood Frequency Analysis was done by Benson (1950), but it was not until the 80's when the scientific community started to focus on this topic. In particular, it must be underlined the works of Stedinger, who succeeded in proving the value of this information.

Basically, the use of historical information to improve the Flood Hazard Assessment must be done in three steps: historical information acquisition (maximum water levels), conversion of this information into the appropriate data (discharges), and the final assignment of the corresponding probability trough an statistical analysis. Five papers are presented in this book covering these three aspects of the Flood Hazard Assessment using historical information.

i) Two papers presented by Llasat and Barriendos and Naulet et al. focus on the acquisition of historical data and its potential use, describing the different documentary sources and the type of information can be found in Spain and France respectively. Llasat and Barriendos propose a magnitude classification as a function of the reported damages, and as an initial result, they found for the Iberian Peninsula three climatic oscillations for the last five centuries. On the other hand, Naulet et aI. establish historical data acquisition must be done in a first steps by a General State of Sources, followed by the Data Collection.

ii) The paper by Fernandez de Villa/ta and Benito deals with the use of a specific database for this type of information. They describe the database structure and the interface with the user using a Geographic Information System. They present an application to the Tagus river in Spain, and also they found a non-stationarity behaviour of the flood frequency at historical time scale.

iii) The reconstruction from historical flood data of the historical discharges needs the use of the appropriate hydraulic model. One example is presented by Pagliara for the Versilia river in Italy. He uses a 2D unsteady model and stresses

xxii T. GLADE, P. ALBINI AND F. FRANCES

the important role of the evolution of the hydraulic characteristics of the floodplain, mainly due to human structures.

iv) Lastly, Frances describes the different types of historical information from the statistical point of view and how to use historical and systematic information together in the frequency analysis using the Maximum Likelihood framework. The value of the historical information is also analysed.

4. Landslide Hazard Assessment

The potential of historical data to increase reliability of landslide hazard assessments has long been recognised. However, a conceptual background for applying collected historical data to landslide hazard assessments is missing. This is due to a number of factors:

• Data on historical events are not complete, in particular from these events having been occurred in the previous centuries.

• Different types of investigations lead to results difficult to compare, e.g. personnel mapping landslides in the field may recognise failures differently.

• Recorded data is classified in non-comparable ways. • Accuracy of historical data is difficult to validate. • Changing environmental conditions are generally not considered.

The minimum information available, however, is the date and possibly the location of occurrence. Although it seems trivial, this information is of particular importance to calculate temporal and spatial probability of occurrence. Therefore, this data is mostly applied in landslide hazard assessments which consider historical data.

These general issues are also reflected by the papers presented in the landslide part of this book based on examples from various locations in the world. The following paragraph summarises these papers.

For Northern Italy, Rizzo et al. use already published reports, State Archives and bibliographic sources and compare the compiled landslide inventory with daily rainfall data. They are able to differentiate first failures from reactivated landslides and demonstrate that most landslides were triggered by intensive storms or prolonged wet periods. In addition, damage caused by landslides and floods is summarised. It is envisaged to apply these results to forecasting and hazard evaluation.

Calcaterra and Parise search inventories in Southern Italy of the Ministry for Public Works, the archive of the Italian A VI-Project (refer to Guzzetti et al. 1994 for more details), newspapers, scientific publications, and other local sources (private archives, homeowners, etc.) for relevant landslide data. Various levels of reliability of the different data sources have been established: high to moderate for scientific publications, low to moderate for newspapers and for local administrative and management agencies respectively, and low for other sources. Despite these limitations, they are able to compile an inventory including date and location of event, slope movement typology, caused damage, and triggering factors. It is noted that environmental changes such as deforestation in particular in the last century might have a strong influence on landslide data, however it was not possible to quantity this input.

INTRODUCTION TO THE USE OF HISTORICAL DATA xxiii

Glade reviews results from landslide hazard research in Rheinhessen, Southwest Germany and in Hawke's Bay, New Zealand. In both studies, historic landslide data for a specific region were compiled. Sources include newspapers, scientific and government reports, and other archives. Both inventories are based on collections of preliminary, already published landslide data which are extended to more spatial and temporal detail. It was possible to add information on further events through landslide locations and magnitudes, triggering conditions and related damage. However, temporal landslide information was used for spatial landslide assessment for Hawke's Bay only.

The landslide susceptibility map for Rheinhessen gives the spatial probability of occurrence based on 240 landslides triggered by a rainfall event in winter 1981182 with 50 year return period. For New Zealand, the temporal probability of landslide occurrence was calculated with a spatial rainstorm probability surface for a 10 year recurrence interval. 10,893 landslides have been mapped and used within this analysis. The final map gives approximate locations of hazardous areas. In the latter hazard assessment, however, a spatial probability of rainfall magnitude over a given period has been included. This allows to calculate landslide hazard scenarios for other periods, thus is a valuable tool for planners and practitioners. Maps of both regions give spatial distribution of potentially hazardous areas within a predefined region, however, the New Zealand landslide hazard assessments includes temporal probability surfaces, which can be changed for specific scenarios. But they both reflect preliminary results only, validation has to be undertaken before they can be used for official governmental planning procedures.

For the United States, Alger and Brabb have undertaken a huge effort to summarise landslide data distributed throughout the US in order to compile a landslide database available for further use in the beginning of the 1980's. Various data sources have been accessed: available library database services, own systematic library studies, and reference collections from individual researchers. As one of the outputs, a debris flow inventory and susceptibility map has been published in 1984 indicating areas prone to landslides. A reconnaissance performed in 1998 and 1999 added further data to this inventory and a map showing debris flow locations for the US is presented.

All publications show the methodology involved in collection historical landslide data, mention the different sources to be accessed, and the difficulties involved in such a research. Each presentation gives examples of applications of such historical landslide information and demonstrate the preliminary origin of this research.

Future research should focus in particular to extend already existing data bases, increase accuracy of data, validate data, and develop an overall conceptual framework on various applications of such data to landslide hazard assessments.

5. Conclusion and Perspectives

Current methodological approaches of natural hazard assessment are aiming a reduction of the limitations presented by various contributions to this volume. Indeed these limitations are not the same in different parts of the world. Previous three chapters summarise various approaches and methods used in different disciplines for including historical data into natural hazard assessments. Indeed, some studies are strongly discipline dependent, however, most demands to undertake such approaches reflect

xxiv T. GLADE, P. ALBINI AND F. FRANCES

general requirements. These general issues addressed by the presented contributions are focussing on:

• parametric catalogues and data bases; • acquisition of historical data; • reliability assessment of historical sources; • influence of temporal and spatial changes of geosystem to historical data; • introduction of probabilistic analysing methods; • modelling approaches including both modelling historical events ('back­

analysis') and compiling historical and systematic data into frequency analysis; • potential applications and benefits for end-users; and • develop a methodology or general recommendations to be used by technicians in

practical studies.

Based on presented approaches in addressing and partly solving these topics, research perspectives for the use of historical data in natural hazard assessments include aspects on:

• improvement of quantity and quality of chronological data series; • reduction of the uncertainty associated with the incompleteness of the nOD­

instrumental records; • new methods on how validated historical data could further contribute to natural

hazard assessment; • compilation of multi-hazard data-bases and approaches; • development of a non-probabilistic method of calculation of natural hazard; • validation of resulting hazard maps; • application of natural hazard assessments for scenario modelling; and ultimately • relevance of historical data within early warning systems for defmition of

triggering thresholds as well as for preventive measures through natural hazard maps.

These perspectives direct towards potential research issues aiming to improve data bases and inventories, to suggest analysis methods and approaches, and to encourage application of natural hazard assessments to practical planning and management procedures. The use of historical data for future natural hazard assessments is highly encouraged.

6. References

Ambraseys, N.N. (1983) Notes on historical seismicity, BSSA, 73 (6), 1917-1920. Benson, MA (1950) Use of Historical Data in Flood Frequency Analysis. Eos, Trans. AGU, 31 (3), 419-424. Boschi, E., Guidoboni, E., Ferrari, G., Valensise, G. and Gasperini, P. (eds.) (1997) Catalogo dei forti

te"emoti in [talia dal461 a.c. a11980, vol 2. lNG-SGA, Bologna, 644 pp. Gasperini, P., Bernardini, F., Valensise, G. and Boschi, E. (1999) Defining Seismogenic Source from

Historical Earthquake Felt Reports, BSSA, 89, 94-110. Giardini, D. (1999) ) The Global Seismic Hazard Assessment Program (GSHAP) - 199211999, Annali di

Geofisica, 42 (6), 957-974.

INTRODUCTION TO THE USE OF HISTORICAL DATA xxv

Giardini, D. and Basham, P.W. (1993) The Global Seismic Hazard Assessment Program (GSHAP), in GSHAP Technical Planning Volume, edited by D. Giardini and P.W. Basham, Annali di Geofisica, 36 (3-4), 3-13.

Guidoboni, E. and Stucchi, M. (1993) The Contribution of Historical Records of Earthquakes to the Evaluation of Seismic Hazard, in GSHAP Technical Planning Volume, edited by D. Giardini and P.W. Basham, Annali di Geofisica, 36 (3-4), 201-215.

Guzzetti, F., Cardinali, M. and Reichenbach, P. (1994) The A VI Project: A bibliographical and archive inventory oflandslides and floods in Italy. Environmental Management, 18(4): 623-633.

Hooke, 1.M. and Kain, R.I.P. (1982) Historical change in the physical environment: a guide to sources and techniques, in K.1. Gregory (ed.), Studies in Physical Geography, Butterworth Scientific, London.

Levret, A., Cushing, M. and Peyridieu, G. (1996) Etude des caracteristiques de seismes historiques en France. Atlas de 140 cartes macrosismiques. Institut de Protection et de Surete Nucleaire, Departement de Protection de I'Environnement, Bagneux, 399 pp. + 140 maps.

Mc Guire, R.K. (1993) Computations of seismic hazard, in GSHAP Technical Planning Volume, edited by D. Giardini and P.W. Basham, Annali di Geofisica, 36 (3-4), 181-200.

Stedinger, J.R., and Cohn, T.A. (1986) Flood Frequency Analysis with Historical and Paleoflood Information. Water Res. Res., 22 (5),785-793.

Trimble, S.W. (1998) Dating fluvial processes from histoncal data and artifacts, Catena 31, 283-304. U.S. Earthquake Intensity Database (1638-1985) NGDClNOOA.

http://www.ngdc.noaa.gov/seglhazardlegint.html Varnes, DJ. (1984) Landslides hazard zonation: a review of principles and practice, UNESCO, Paris. Vogt, 1. (1989) Historical seismology. Some notes on sources for seismologists, in M. Stucchi (ed.), Materials

of the CEC project "Review of Historical Seismicity in Europe", CNR, Milano, vol. I, 15-24.