Il sistema MOSE: Integrazione fra la difesa dalle acque alte e la protezione dell ambiente lagunare dall erosione.

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1 Enrico Marchi Lecture 31 maggio 2013 Politecnico di Milano, Aula Rogers Via Ampère 2, Milano Il sistema MOSE: Integrazione fra la difesa dalle acque alte e la protezione dell ambiente lagunare dall erosione. Giovanni Cecconi Consorzio Venezia Nuova Thetis SpA

2 A COMPLEX SYSTEM VENICE PORT LAGOON

3 Fish farms Historical places Torcello year 900 Salt marshes Barrier Islands

4 Buildings and Rooftop Terraces by Vittore Carpaccio1494

5 16th Century

6 Ecotourism : 1908 Hotel Excelsior Post Card

7 LAND / WATER COOPERATION- COMPETITION: XVII CENTURY IDEA OF CO-EVOLUTION

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9 From a footprint to a salt-marsh A protected place open to the natural flow of matter and solar energy

10 SELF-STRUCTURING COMMUNITIES: MICROBIAL MATS

11 AN EVOLVING LANDSCAPE : FROM 50 YEAR OLD SALT- MARSH (on the right) TO 5 YEAR OLD NEW SHOALS (on the left) ARTIFICIAL LANDSCAPE BY COMPACTION OF SEDIMENT FILLS

12 EU Priority List Habitat 1150 Coastal Lagoon 1510 a limonieto Habitat of EU Importance 1310 a salicornieto 1320 a spartinion 1420 a sarcocornieto 1410 a giunco Salt Marsh Habitat Lost salt marshes Remaining salt marshes YEAR AREA Loss (km2) km , ,5

13 INTERTIDAL HABITAT LOSS DUE TO R.S.L.R km km 2 60 km 2

14 Erosion due to R.S.L.R YEAR WATER DEPTH (m) increase in harmouring , , , ,

15 ENVIRONMENTAL EFFECTS of R.S.L.R STATE OF REFERENCE PRESENT STATE No waves Low turbidity High turbidity High waves Light Penetration Shoals No shoals, Re-suspension Eel Grass and Benthic Species on well Oxidized Layer Self-Mantained Tidal Flow Channels Siltation of Channels Opportunistic Species in anoxic sediment (less biodiversity)

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17 November, 4th 1966

18 November, 4th 1966

19 VENICE R.S.L.R

20 1 DEC Flooding > 140 cm

21 Limits to Urban Adaptation

22 ADAPTATION of SALT MARSH to R.S.L.R. 0.5 cm/year of NATURAL ACCRETION

23 THE VENICE SOLUTION IMPORT OF LARGE VOLUMES OF SAND TIDAL FLOW CONTROLL IMPORT OF LARGE VOLUMES OF MUD

24 PROTECTED BEACH NOURISHMENT

25 PELLESTRINA ISLAND 12 YEAR AFTER SAND NOURISHMENT

26 WIND DRIVEN SEDIMENT FENCES

27 RE-USE OF DREDGED SEDIMENTS FOR CONSTRUCTING SALT MARSH HABITAT

28 During 26 years a volume of m 3 of sediment from maint. dredging has been re-used on 15 km 2 for constructing n. 120 inter-tidal habitats: - salt marshes - tidal flats

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30 CONSTRUCTED SALT-MARSH HABITATS Limonieto Salicornieto Sarcocornieto

31 Catching of Crangon crangon, a delicious Venetian grey scrimp. < 20% < 40% < 60% < 80% <100%

32 Endangered Breeding Species at Constructed Salt-Marshes (years ) Avocet (39-44 pairs) Redshank (94-136) Black-winged Stilt (96-69) Kentish Plover (34-71) Oystercatcher (31-38) Shelduck (12-17) Little Tern ( ) Yellow-legged Gull ( )

33 Venice Conservation and Development as the Regulation of C onfined O ntic O pen S ystems C.O.O.S. Prof. E.Tiezzi, Space,sediments,tidal controll for hydro-morphological and biological stabilization driven by: - Wind, Wave, Tidal Energy: water and sediment transport - Solar Energy: organic production carbon sequestration biodiversity

34 Restoration of Six Self-Structuring Habitats: Oyster and Mussels. tidal flushing and wave protection Microbial Mats.. accretionary shoals Eel-grass. tidal flats Fragmites... vegetation at river oulets Alophitic vegetation... salt marshes Ammophila litoralis. dune plants to protect beaches. Ecological Services: Self-adaptation to R.S.L.R. Development and conservation of tidal network Motor boat and wind wave protection Sequestration of sediments, pollutants, CO2 Support for benthic species, juvenile fish, insects, birds

35 Coastal Management Motto From: Land reclamation Strong defense structures Low impact planning and design To: Sustaining ecosystem services Ecosystem approach and eco-dynamic design Earlier integration of nature conservation and economic development Examples: UK : Realignment NL : Growing with the sea (NL)->Space to the water -> More Space to More Water (NL)->Hand in Hand -> Building with Nature Japan, Louisiana..: Resilient flood protections Venice: learning from nature

36 Urban mounds: Tokyo-Edogawa super-levee

37 Building with Nature: Nourishment of the coastal sand-river Netherlands

38 Offshore islands as a building with nature coastal protection Source: West 8