“Acqua Alta” and the need for the Mo.S.E. project Managing the coastal flood in Venice May 14, 2020 Preface “Acqua Alta” and the need for the Mo.S.E. project Managing the coastal flood in Venice University: TU Delft Course code: CIE4061-09 Date of submission: May 14, 2020 Supervisors: Prof. Dr. Ir. S.N. Jonkman Dr. Ir. A. Antonini Dr. Ir. M.A. Diaz Loaiza Dr. E.J. Houwing Author names and student numbers: G. Godlewski 5009839 L. Caporalini 5157765 B. Deuss 4480902 Disclaimer: This report is the result of an independent student research project at TU Delft for educational purposes. The findings in this report do not necessarily reflect the positions of the University and/or supervising staff members involved. Preface The SAFElevee project at Delft University of Technology focuses on levee performance and failure, and analyses the interrelated processes of (initial) failure of a levee and breach development, both at a system-macro scale as well as for individual failures. To support the different work packages of this project an international levee performance database has been developed. A second section provides more details on the database and the type of information provided by the database. This report is the product of a multidisciplinary project we conducted as part of our M.Sc. program at the faculty of Civil Engineering and Geosciences of the Delft University of Technology. The multidisciplinary project is performed on behalf of Prof. Dr. Ir. Bas Jonkman. It is part of a fact-finding research for the flooding of Venice in November 2019, conducted by the Delft University of Technology. The report focuses on the meteorological and physical description of the flood event, the protection of the lagoon surrounding Venice and the impact the flood event had on the area. We hope that this report will contribute to the fact-finding research of the Venice flooding in 2019 and to water safety of Venice in general. We also want to address a special word of thanks to our supervisors Dr. Ir. Manuel Diaz Loaiza, Dr. Ir. Alessandro Antonini, Dr. Erik- Jan Houwing and Prof. Dr. Ir. Bas Jonkman, who have supported us during the process and were always happy to help. The report was developed in collaboration with Dr. Ir. Giovanni Cecconi, director of the Venice Resilience Lab and former director of the Control Room, who granted us with an interview, providing precious information, vital to write the report. Also Dr. Ir. Peter van Westendorp, civil engineer professional at Strukton Civiel Projecten B.V., collaborated proving information about Strukton’s experience within the Mo.S.E. project and CNR- ISMAR Venice helped providing precious data and information about the lagoon hydrodynamics. Gabriela Godlewski Luisa Caporalini Bram Deuss Delft, May 2020 Acknowledgments: This research was supported by the NWO project SAFElevee No. 13861. Special thanks and mention to Dr. Sandra Fatorić for her help with the cultural heritage assessment and guidance, to Ir. Giovanni Cecconi for sharing literature, organizing the failed field trip (not executed due to coronavirus crisis) and the interview performed. Many thanks also to CNR- ISMAR, particularly to Dr. Christian Ferrarin and Dr. Alvise Benetazzo for the provided data and detailed information on the lagoon hydrodynamics. Finally, to Dr. Sebastiano Carrer (Thetis S.p.A.), Ir. A. Scotti, Dr. Alessandra Crossato (IHE), Ir. Peter van Westendorp (Strukton) for their priceless comments and experience with the MoSE project, to Prof. G. Seminara (University of Genoa) for his detailed reconstruction on the development of the studies that interested the Venice lagoon and to the Comune di Venezia - Centro Maree for making the sea level data available. Acknowledgments Index CHAPTER 1: INTRODUCTION 3 1.1 About the report 3 1.2 Objective 3 1.3 Structure of the report 4 CHAPTER 2: SYSTEM OVERVIEW 5 2.1 Venice Lagoon 5 2.1.1 Configuration ......................................................................................................................................5 2.1.2 Ecology ................................................................................................................................................5 2.1.3 Morphologic History ...........................................................................................................................6 2.2 The History and Heritage of Venice 7 CHAPTER 3: HYDRAULIC CONDITIONS OF THE VENICE LAGOON AND ANALYSIS OF THE NOVEMBER 2019 STORM SURGE 9 3.1 Introduction 9 3.2 Atmospheric and Meteorological Tides 11 3.2.1 Tidal Components of the Venice Lagoon ....................................................................................... 12 3.2.2 Analysis of Tidal Data ...................................................................................................................... 13 3.3 Meteorological Summary of 12 November 2019 Event 13 3.4 Return Periods of Venice Lagoon 18 3.5 Hydrologic criteria pertaining to Mo.S.E. operation 21 3.6 The influence of climate change on return periods 24 3.7 Conclusion 27 CHAPTER 4: IMPACT AND DAMAGES 28 4.1 Introduction 28 4.2 Online literature and news articles 28 4.2.1 The flood .......................................................................................................................................... 29 4.2.2 Flooded areas .................................................................................................................................. 29 4.2.3 Impact .............................................................................................................................................. 30 4.2.4 Damages .......................................................................................................................................... 30 4.2.5 Heritage ............................................................................................................................................ 30 4.2.6 Local measures ............................................................................................................................... 31 4.2.7 Summary Priced and Unpriced Damages ...................................................................................... 32 4.2.8 Relation to earlier floods ................................................................................................................. 32 4.3 Flooded Area and Damages Model 33 4.3.1 Bathtub Model ................................................................................................................................. 34 4.3.2 Surface Level and Water Level Elevation ...................................................................................... 35 4.3.3 Comparing the Data ........................................................................................................................ 35 4.3.4 Geographic Information System ..................................................................................................... 36 4.3.5 Open Street Maps............................................................................................................................ 36 4.3.6 Analysis of Results .......................................................................................................................... 38 4.4 Validation of the Model 39 4.5 Flooded objects 43 4.6 Cost of Damages 44 4.6.1 Damage numbers ............................................................................................................................ 45 4.6.2 Damages to houses ......................................................................................................................... 47 4.6.3 Damage to industry ......................................................................................................................... 47 4.6.4 Damage to health services ............................................................................................................. 48 4.6.5 Damage to education ...................................................................................................................... 49 4.6.6 Damage to sports facilities ............................................................................................................. 49 4.6.7 Damage to roads ............................................................................................................................. 50 4.6.8 Damage to churches ....................................................................................................................... 50 4.6.9 Total Damages ................................................................................................................................. 51 4.7 Cultural heritage 51 4.7.1 Amount of flooded cultural heritage .............................................................................................. 52 4.7.2 Damages to cultural heritage ......................................................................................................... 53 4.8 Flooded area 53 4.8.1 Approach .......................................................................................................................................... 53 4.8.2 Statistics flooded area .................................................................................................................... 56 4.9 Closed Mo.S.E. barrier 57 4.9.1 Damages with closed Mo.S.E. barrier ............................................................................................ 59 CHAPTER 5: THE MO.S.E. PROJECT AND ITS DELAY 61 5.1 Introduction