Venice sustainability and the impacts of the flood protection barriers

Transcription

1 Venice sustainability and the impacts of the flood protection barriers Paul Linden & Cristina Nasci DAMTP, University of Cambridge Thetis SpA, Venice IUGG June 29, 2011 p.1/35

2 Venice and the Lagoon The historical city The industrial port IUGG June 29, 2011 p.2/35

3 Historical lagoon 16th Century IUGG June 29, 2011 p.3/35

4 Historical lagoon Vestri th Century IUGG June 29, 2011 p.4/35

5 Human intervention 19th 20th Centuries Reclamation of the rivers Sile and Dese ( ) Airport (1958) Bridge across the lagoon railway 1846 highway First industrial zone (1917) Second industrial zone ( ) Third industrial zone ( ) Fish farms (since 1900) Reopened fish farms ( ) Fish farms (since 1900) Lido-Marittima-Marghera Canal ( ) Lido jetties ( ) Malamocco-Marghera Canal ( ) Malamocco jetties ( ) Romea highway ( ) Chioggia jetties ( ) IUGG June 29, 2011 p.5/35

6 Local mean sea level Eustatic change and subsidence livello medio del mare nel mean sea level in Natural trend Eustasy Natural subsidence Man-induced subsidence trend naturale trend influenzato da sfruttamento artesiano rebound trend attuale Trend caused by the use of artesian wells Rebound Total reduction in the difference between ground level and sea level (cm) 23 perdita 24 totale di quota del suolo (cm) rispetto al livello medio del mare nel Actual trend IUGG June 29, 2011 p.6/35

7 Subsidence Canaletto (1730 ca) IUGG June 29, 2011 p.7/35

8 Lagoon habitats Fish farms Historical places - Island of Torcello (year 900) The littorals Barrier Island of Pellestrina Wetlands IUGG June 29, 2011 p.8/35

9 Intertidal habitat Loss due to subsidence and RSLR km km 2 60 km 2 IUGG June 29, 2011 p.9/35

10 Lagoon becomes a bay Changes to morphology Mainland Lagoon Sea IUGG June 29, 2011 p.10/35

11 Flooding 1 dicembre Flooding > 140 cm Increase in the frequency of flooding > 110cm IUGG June 29, 2011 p.11/35

12 Storm surge November, 4th 1966 IUGG June 29, 2011 p.12/35

13 Flooding VENICE, LAST HIGH WATER OF 01/12/2008 IUGG June 29, 2011 p.13/35

14 Adaptation Range of safeguards Protected beach nourishment cutting of creeks and ponds Salt marshes restoration Pioneer vegetation Biodiversity: 7 species Dune management Mobile tidal barriers IUGG June 29, 2011 p.14/35

15 Reinforcement of the litoral Intervention areas Works underway Works completed Works completed Cavallino Jesolo-Cortellazzo Eraclea Beach reconstruction 45 km Dune restoration 8 km Reinforcement of jetty 11 km Lido Pellestrina Sottomarina Isola verde IUGG June 29, 2011 p.15/35

16 Reinforcement of the litoral Coastline reinforcement new groynes submerged artificial reef new beach lagoon-side embankments S. Pietro in Volta Pellestrina IUGG June 29, 2011 p.16/35

17 Pellestrina littoral before Before After IUGG June 29, 2011 p.17/35

18 Recovery of morphology Intervention areas Works completed North lagoon Channel dredging 180 km Reconstruction of mudflats and salt marshes 1,430 hectares Central lagoon South lagoon Environmental restoration of islands 12 islands IUGG June 29, 2011 p.18/35

19 Environmental restoration RE-USE OF SEDIMENTS FOR SALT MARSHES IUGG June 29, 2011 p.19/35

20 Environmental restoration Salt marsh evolution 1 year 9 years IUGG June 29, 2011 p.20/35

21 MOSE Modulo Sperimentale Elettromeccanicon Location of the Mose Flood Barriers IUGG June 29, 2011 p.21/35

22 MOSE Each gate THE MOSE FLOOD BARRIERS rows of gates installed in the bed of the inlets; 78 gates (Lido 21+20;Malamocco 19; Chioggia 18) "mobile" gates because in normal tidal conditions they are full of water and rest in their housing structures "caissons" on the seabed; emission of compressed air empties the gates of water until they emerge box-like metal structure attached to the concrete caisson in which it is housed by means of two hinges 20 m wide with a variable height and width according to the depth of the inlet channel average inlet closing time is from 4 to 5 hours lagoon sea IUGG June 29, 2011 p.22/35

23 MOSE Gates IUGG June 29, 2011 p.23/35

24 MOSE Operation < a < Lagoon Sea > b c d e IUGG June 29, 2011 p.24/35

25 MOSE Hinge system The male element raised above the female element IUGG June 29, 2011 p.25/35

26 MOSE Lido inlet - new construction The new lay-out after realization of the Mose System lagoon Cavallino - Treporti Refuge haven with lock Row of gates (Lido - Treporti) New island between the rows of gates Row of gate (Lido - S. Nicolò) New configuration of the south bank Breakwater Lido - S. Nicolò sea 6 IUGG June 29, 2011 p.26/35

27 MOSE Lido inlet titolo Venice new configuration of the south bank new island refuge haven (sea-side basin - temporary work site for the gate caissons) lock Cavallino - Treporti IUGG June 29, 2011 p.27/35

28 Arsenale Control centre IUGG June 29, 2011 p.28/35

29 Arsenale Restoration IUGG June 29, 2011 p.29/35

30 Climate change Sea level rise Seattle San Francisco San Diego 2 cm/decade consistent with estimates of global SLR IUGG June 29, 2011 p.30/35

31 High tide + storms Winter 1983 storms High tide levels vary by about 1 m Highest storm-forced level = 28 cm IUGG June 29, 2011 p.31/35

32 Sea level rise predictions San Francisco hourly sea level cm mb Under projected global warming, such as in the GFDL A2 simulation sea level rises considerably by 2100, in this scenario by approximately 0.9m. IUGG June 29, 2011 p.32/35

33 Venice tides Water Level (cm) Observed Water Level Predicted Astronomical Tide Punta Salute - December Day of Month IUGG June 29, 2011 p.33/35

34 Vulnerability chart A tool for assessing vulnerability IUGG June 29, 2011 p.34/35

35 Science-based management Assessment IUGG June 29, 2011 p.35/35

36 Science-based management Assessment monitoring of physical, chemical properties IUGG June 29, 2011 p.35/35

37 Science-based management Assessment monitoring of physical, chemical properties monitoring of biological components IUGG June 29, 2011 p.35/35

38 Science-based management Assessment monitoring of physical, chemical properties monitoring of biological components Decision map for MOSE operation IUGG June 29, 2011 p.35/35

39 Science-based management Assessment monitoring of physical, chemical properties monitoring of biological components Decision map for MOSE operation impacts on Lagoon IUGG June 29, 2011 p.35/35

40 Science-based management Assessment monitoring of physical, chemical properties monitoring of biological components Decision map for MOSE operation impacts on Lagoon public information IUGG June 29, 2011 p.35/35

41 Science-based management Assessment monitoring of physical, chemical properties monitoring of biological components Decision map for MOSE operation impacts on Lagoon public information Re-assessment IUGG June 29, 2011 p.35/35

42 Science-based management Assessment monitoring of physical, chemical properties monitoring of biological components Decision map for MOSE operation impacts on Lagoon public information Re-assessment commit to regular schedule IUGG June 29, 2011 p.35/35

43 Science-based management Assessment monitoring of physical, chemical properties monitoring of biological components Decision map for MOSE operation impacts on Lagoon public information Re-assessment commit to regular schedule include ecosystem services IUGG June 29, 2011 p.35/35

44 Science-based management Assessment monitoring of physical, chemical properties monitoring of biological components Decision map for MOSE operation impacts on Lagoon public information Re-assessment commit to regular schedule include ecosystem services Impacts of climate change on all of the above IUGG June 29, 2011 p.35/35

45 Science-based management Assessment monitoring of physical, chemical properties monitoring of biological components Decision map for MOSE operation impacts on Lagoon public information Re-assessment commit to regular schedule include ecosystem services Impacts of climate change on all of the above The Venice Conference: Improving the capacity to assess and to adapt to climate change in urban coastal regions September 12 15, 2011 Venice, Italy IUGG June 29, 2011 p.35/35