Deep Ecology in the Venetian Lagoon

Deep Ecology in the Venetian Lagoon Design research and scenario construction in the context of sea level rise Ricardo Avella

Deep Ecology in the Venetian Lagoon Design research and scenario construction in the context of sea level rise

Ricardo Avella Fall Semester 2018-2019

IUAV - Università Iuav di Venezia EMU – European Post-master in Urbanism avella.ricardo@gmail.com

IUAV-EMU 2018-2019 Design Studio Course instructors

Paola Viganò IUAV-EMU Programme Director

Alvise Pagnacco Mariano Andreani Giambattista Zaccariotto Sybrand Tjallingii Qinyi Zhang Paola Pellegrini

Fig. 1  A road on top of a dike, separating the marshlands of the Venetian Lagoon with the productive fishing valleys of Cavallino-Treporti (Source: photograph taken by the author).

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Deep Ecology in the Venetian Lagoon

Introduction The following essay is the result of the IUAV-EMU studio project, aimed at exploring the consequences of sea level rise in the Venetian Lagoon at the broader scale, but shifting the attention from the much studied city of Venice to the peripheral peninsula of Cavallino-Treporti, at both the intermediate and local scales. The design studio took a prospective approach (Viganò, 2016), based on the construction of four different scenarios and exploring them in depth by following a coherent sequence of hypothesis through design. This essay will describe the construction of one of these four scenarios, and the subsequent design explorations.

To facilitate a better understanding of how this scenario was built, the first part of this essay will focus on the problem of sea level rise and its uncertainties. The questions raised around the efficacy of the MOSE project, and the study of other anthropic interventions that have negatively altered the hydraulic dynamics of the Venetian Lagoon over time, will also be briefly analyzed. Having framed the problem, the construction of the scenario will be explained in the second part of the essay.

The ideas behind the Deep Ecology movement will be presented, and from that ecological perspective a series of possible strategies for a transition towards a biocentric lagoon will be enunciated. In the following part, the consequences of this scenario will be explored at the intermediate scale in Cavallino-Treporti, putting particular attention to the interaction of culture and natural processes. Then, three zooms will be explored at the smallest scale. But in the search for a resilient strategy that could evolve into a pilot project, one of them was studied more in depth than the others. Finally, some conclusions are drawn that may prove useful for further research and policy-making.

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Fig. 2  The Venetian Lagoon and its relation with the Adriatic Sea, today (Source: made by the author, with data from the Geoportale Regione Veneto).

Sea and Lagunar Canals

Shallow Waters (Velme)

Marshlands (Barene)

Dry Land

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An egocentric lagoon against sea level rise The Venetian Lagoon is an enclosed bay of the Adriatic Sea, characterized by its brackish shallow waters (velme in Italian) and a rich ecosystem that depends on the existence of salt marshes (barene), intermittently revealed and submerged depending on tidal fluctuations that change by the hour. But this lagoon, compared to similar water bodies around the world, is far from being a natural environment.

It is an artificial construction shaped by the Republic of Venice, which understood that the relation between the city and the surrounding lagoon was of the utmost importance if the military and trading advantages they had were to be preserved.

For this reason, the territory became a project. Over centuries rivers were diverted to avoid sedimentation, canals and dikes were built to prevent flooding, and vast surfaces of marshlands were dried up to reclaim new land. Huge amounts of resources and energy were invested in this territory so that the city could be saved from the risks posed by the rivers that flowed into the lagoon, but also from those brought by the Adriatic Sea.

Deep Ecology in the Venetian Lagoon

Although the Republic of Venice came to an end in 1797 with the arrival of the Napoleonic invasion, this trend of controlling risks with forms of resistance persists to the present day. The Venetian Lagoon continues to be artificially managed in different ways and at different scales; but in the context of climate change, the risks posed by sea level rise could have a profound and definitive impact on the lagoon, making all these forms of resistance completely irrelevant. In 2001, the Intergovernmental Panel on Climate Change (IPCC) estimated a sea level rise of around 18 to 59 cm by the end of this century, a number that today is considered underestimated by many experts (Umgiesser et al., 2011). The current estimates for sea level rise by 2100 may change depending on the authors, but they are all significantly higher. In 2008, Horton et al. gave an estimate of 54 to 89 cm, acknowledging that this could be a lower limit; Grinsted et al. (2009) calculated a sea level rise of around 72 to 160 cm (or 96 to 215 centimeters, depending on the melting of the ice caps); the numbers given by Vermeer and Rahmstorf (2009) range from 75 to 190 cm; and Jevrejeva et al. (2010) estimate a sea level rise between 60 and 160 cm. In other words, the average sea level rise calculated by any of these scholars exceeds by far the highest cipher given by the IPCC in 2001.

Fig. 3 IPCC (2001) estimated a sea level rise of 18 to 59 cm by 2100, a number that today is considered underestimated​by many experts (Source: Umgiesser et al., 2011).

Fig. 4 Today, the estimates for sea level rise by the year 2100 are many and vary a lot depending on the author, but all of them more dramatic (Source: Umgiesser et al., 2011).

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To protect the Venetian Lagoon from high waters and extreme events such as sea level rise, the Consorzio Venezia Nuova launched the MOSE Project during the 1980s.

The final design of the MOdulo Sperimentale Elettromeccanico was completed in 2002, and construction began the following year. And even though the works are currently on hold, more than 85% of the project has already been built. Regardless of the scandals and the uncertainty surrounding its completion, what worries are the number of questions that have been raised by the scientific community regarding its efficacy in the long-term. Designers did consider the risks posed by sea level rise while elaborating the final version of the project, but the estimates acknowledged at the beginning of the new millennia were significantly lower than the ones taken into account by academics and experts today. In fact, the scenario that was recommended for the MOSE project only considered a sea level rise of 22 centimeters. In a report published by UNESCO in 2011 regarding the future of Venice and its lagoon, Georg Umgiesser argues that “these estimates were clearly given at a time when climate change and sea level rise were still highly debated” (Umgiesser et al., 2011). As described above, the most updated models estimate a sea level rise of 54 to 215 cm by the end of this century; so it can be said that the skepticism around the MOSE project is at least scientifically grounded.

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Fig. 5  Different images of the infrastructures built for the MOSE Project, which has the capacity to protect the Venetian Lagoon from tidal surges as high as 2.74 meters. Nevertheless, it was only engineered to handle a median of 22 centimeters of sea level rise in 2002 (Retrieved from: https://www. mosevenezia.eu).

The MOSE has the capacity to protect the Venetian Lagoon from occasional tidal surges as high as 2.74 meters (a peak event), but it was designed to handle a sea level rise of 22 centimeters. With those numbers in mind, the engineers involved in the project expected the MOSE to close its mobile gates 10 times a year. But Georg Umgiesser points out that with 50 centimeters of sea level rise, the MOSE will be closed once a day; and that with 70 centimeters the mobile gates will be closed more often than open at the three inlets of the lagoon (Goodell, 2017). The problem is that some scientists believe we could have 60 cm of sea level rise in less than 30 years, and that if the level goes beyond 80 cm, the Adriatic Sea will enter the lagoon from the north and from the south (Goodell, 2017), making the gates at the inlets a mere triviality.

According to the UNESCO report on the future of Venice in the context of sea level rise, the most plausible sea level by 2100 will be 80 centimeters (Umgiesser et al., 2011). This was the number used to construct a first scenario: a starting point to explore through design the consequences of sea level rise in the Venetian Lagoon. It must be said that 80 centimeters was considered as the median, so the tidal fluctuations that can make the sea level change by the hour needed to be contemplated as well for the design explorations. By analyzing the data on tidal fluctuations available at the website of the Venice Municipality, a level of 50 centimeters was considered as the average for low tides, and a level of 150 centimeters as the average for the high tides. By using topographical data available on the Geoportale Regione Veneto, a rough and approximate visualization of the consequences could be visualized in space with the aid of a geographic infrmation system.

The result of this first exploratory process showed that with a sea level rise of 80 centimeters the Venetian Lagoon will be lost, at least the way we know it. A series of narrow and elongated islands will continue to act as a breakwater against the waves of the Adriatic Sea, but the internal shores will now have saline water instead of brackish water, since the lagoon will have become a branch of the sea. Of course, this will transform the flora and fauna of the lagoon. But we must remember that all the transformations made over centuries around the lagoon has already changed its ecology in a radical way (Foscari, 2014), since the inflow of freshwater from the rivers had been regulated. Sea level rise will also make the complex system of locks, canals, and diversions that used to control the hydraulic regime of the lagoon inconsequential, to say the least. Finally, the city of Venice will be flooded, with only a few parts of it remaining as they are.

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Negative Anthropic Impact on the Venetian Lagoon

Fig. 6 In a scenario with a sea level rise of 1.5 meters, in which the MOSE project will not be able to protect the Venetian Lagoon from flooding, the consequences will be dramatic. If nothing is done, the lagoon will dissappear and become a branch of the Adriatic Sea. The coast will change completely, and more than a half of Venice will be submerged (Source: made by the author, with data from the Geoportale Regione Veneto.

There are other anthropic causes that have created a negative impact on the dynamics of the lagoon. Sea level rise is only one of the problems involved, but since the debate has put so much attention to this particular topic, all the other factors have been minimized. As Luigi D’Alpaos has stated, the Venetian Lagoon will be lost to the sea if the other problems are not considered as well –especially the erosion processes that are currently taking place (D’Alpaos, 2010). The diversion of the tributaries, which took place between the XIV and the XVII centuries, had a profound impact on the lagoon. Its salinity augmented over time, since the discharge of freshwater came to an end; but its average depth also increased as the inflow of fluvial sediments from the rivers was stopped (D’Alpaos, 2010). These diversions initiated the erosion processes, but other man-made interventions made after the fall of the Republic have accelerated them. Particularly the construction of large jetties and breakwaters at the three inlets of the lagoon, which began by the end of the XIX Century; and the dredging of new canals to facilitate the entrance of big ships to the industrial port of Marghera, during the XX Century.

Sea and Lagunar Canals

Shallow Waters (Velme)

Marshlands (Barene)

Dry Land

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Indeed, the construction of long jetties and large breakwaters at the inlets of Chioggia, Malamocco and Lido-San Nicolò, built between 1872 and 1935 to facilitate the entrance of ships to the Venetian Lagoon, changed dramatically the hydraulic dynamics of the water body. The inlets became man-made funnels that drive out the sediments at the bottom of the lagoon and difficult the entrance of new sediments from the Adriatic Sea. Before the construction of the jetties, the exchange of sediments between the lagoon and the sea was in balance. Analyses of the current situation of these exchanges, during the regular tidal fluctuations, show that the outflow of sediments is much greater than the inflow from the sea (D’Alpaos, 2010).

A situation that is resulting in the acceleration of the erosion processes and in the subsequent deepening of the lagoon floor.

Fig. 7 The construction of long jetties and large breakwaters at the inlets of Chioggia, Malamocco and Lido-San Niccolò, changed dramatically the hydraulic dynamics of the lagoon (Retrieved from: https://www.mosevenezia.eu).

Over time, but especially after the construction of the jetties at the inlets and the dredging of the Vittorio Emanuele and Malamocco-Marghera canals, the lagoon has also been losing large surfaces of barene –a Venetian word for the salt marshes that are intermittently revealed and submerged with the tidal fluctuations. According to Luigi D’Alpaos, at the beginning of the XVII Century the surface of barene in the Venetian Lagoon was close to 255 km². By 1900, a third of those marshlands had been lost –around 170 km² in total; and finally, by 1970, this figure had shrunk to 64 km² (D’Alpaos, 2010). In other words, more than 60% of the total surface of salt marshes had been lost in less than 70 years. In absolute figures 106 km² of barene disappeared in 70 years, an alarming number if we consider that before the construction of the jetties at the inlets, the port, and the man-made canals, only 85 km² were lost in 300 years. If one conclusion can be drawn from all these trends, is that the Venetian Lagoon will cease to exist as we know it if nothing is done to prevent it. It will cease to be a shallow water body, and the characteristic landscape of marshlands will finally disappear along with the flora and fauna that depends on those habitats.

Fig. 8 Chart that shows the progressive loss of Barene, from 1600 to the present day (Source: D’Alpaos, 2010).

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Deep Ecology in the Venetian Lagoon

Fig. 9 A view of the Malamocco inlet, between the islands of Lido and Pellestrina (Retrieved from: https://www.mosevenezia.eu).

Fig. 10 The inlets have become funnels that drive out the sediments of the lagoon bed and difficult the entrance of new sediments washed by the sea currents. In this diagrams, we can visualize the input and output balance of the Malamocco inlet before and after the construction of the jetties (Source: D’Alpaos, 2010).

So, from a brief literature review, a list of some of the anthropocentric interventions that managed to have a negative impact on the dynamics of the Venetian Lagoon can be made: 1. The diversion of the tributaries that used to discharge into the lagoon –the Brenta, Sile, Dese and Piave Rivers, among many others–, made by the Republic of Venice between 1330 and 1642. This large project, acted at the scale of the territory, was strictly driven by military purposes. The goal was to prevent the lagoon from silting up with fluvial sediments –an idea that worried many, since it represented the loss of the defensive advantages that came with a city that is surrounded by water.

2. The construction of large jetties and breakwaters at the three inlets of the lagoon –Malamocco, Lido and Chioggia–, from 1872 to 1935. The goal was to reduce the intensity of wave action, leading to the creation of better conditions for ships that needed to enter the lagoon. Sand had to be dredged constantly around the inlets, particularly at the mouth of Lido-San Nicolò, since sediments tended to accumulate on the seabed of the Adriatic Sea. 3. The construction of the Vittorio Emanuele Canal in 1925, aimed to facilitate the entrance of big ships from the Lido inlet and through the Giudecca Canal to the docks of Porto Marghera, an industrial port that had been recently built in the internal part of the lagoon.

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Fig. 11 Chart that shows the progressive deepening of the lagoon floor, from 1800 to the present day.

The numbers reflected in the chart are the average depth of the whole lagoon (Source: D’Alpaos, 2010).

Fig. 12 Over time the lagoon has been loosing sediments to the sea. These dynamics, anthropocentric in nature, are deepening the lagoon floor and reducing the surface of barene -marshlands that are revealed or submerged in relation to the tidal fluctuations (Source: D’Alpaos, 2010).

4. The construction of the Malamocco-Marghera Canal in 1968, aimed to facilitate the entrance of big ships from the Malamocco inlet to the docks of Porto Marghera, through the central part of the Venetian Lagoon. This canal has been recognized as one of the most important contributors in the negative alteration of the hydraulic dynamics of the lagoon, since the erosion processes in the central part have increased greatly since its construction.

5. Wave action inside the lagoon has also accelerated the erosion processes. These waves are created mainly by the movement of big ships (mercantile and industrial vessels, but also the touristic cruise ships). This proves that the activity of the touristic and industrial ports are in conflict with the long-term preservation of the lagoon.

6. To a lesser degree, the abundance of fishing valleys that have been made since the Middle Ages in the north-eastern and south-western parts of the Venetian Lagoon. There is a debate among scholars as to the real impact these man-made fishing ponds may have in the hydraulic dynamics; but still, they have a water regime that is completely independent from that of the lagoon, their dikes block the natural exchange of sediments between the barene and the lagoon floor, and they occupy large surfaces that could help to mitigate flooding during high waters.

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Deep Ecology in the Venetian Lagoon

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Fig. 13  Besides SLR, there are many anthropic causes that have contributed to the negative alteration of natural processes in the Venetian Lagoon. SLR is only one of the risks involved in the long-term preservation of Venice and its lagoon, and the debate has put much of the attention to this topic. If the other problems are not considered, the lagoon will definitely be lost (Source: made by the author, with data from the Geoportale Regione Veneto).

Negative Anthropic Impact on the Venetian Lagoon Source: Geoportale Regione Veneto

Sea and Lagunar Canals

Negative Anthropic Causes

Shallow Waters (Velme)

Fishing Valleys

Marshlands (Barene)

Diverted Rivers

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Canals for Big Ships

Transformation

What if we transform the Venetian Lagoon into a freshwater reservoir?

What if we transform the Venetian Lagoon into a new archipelago in the sea?

Resistance

Resilience

What if we preserve the Venetian Lagoon by bringing back natural processes?

What if we preserve the Venetian Lagoon by controlling its flows and borders?

Preservation

What if we allow natural processes to regulate life once again?

The interventions described in the previous chapter have contributed negatively in the hydraulic dynamics of the Venetian Lagoon (D’Alpaos, 2010), but also in the loss of habitats and in the transformation of its flora and fauna (Foscari, 2014). It could be argued that the ecologies around the water body are as artificial as the lagoon itself, and that the role played by natural processes has been greatly minimized.

It is an egocentric lagoon, modified by humans over centuries to fit the purposes of a political project, and artificially controlled with an engineered approach and with little consideration for other forms of life. The future of Venice depends on the health of the Venetian Lagoon; but paradoxically, venetians themselves have been compromising their existence by shaping and reshaping the lagoon to meet their needs.

Fig. 14 Deep Ecology promotes Biocentric Egalitarianism, a non-anthropocentric concept that considers all forms of life as equally valuable (Retrieved and modified by the author from: https:// www.sydneylatinofilmfestival.org/deep-ecologyworkshop/).

Fig. 15 The Scenario Matrix built by the students of the IUAV-EMU Fall Semester, as part of the Studio project (Source: made by the EMU group: Lamberts, M., Pu, H., Sun, Y., & Avella, R., 2018-2019).

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But what if we take a different approach, and push towards a resilient scenario in which human occupation is not necessarily in conflict with the natural system? What if we find a way in which different forms of life can coexist while preserving –and maybe even restoring– the ecosystem of the Venetian Lagoon? Such a scenario goes beyond ecology and preservation, since it has strong political, social and economic implications. And from a theoretical perspective it is strongly connected to a philosophical school of thought commonly referred to as ‘Deep Ecology’, which states that ‘live and let live’ is always a more powerful ecological principle than ‘either you or me’ (Naess, 1973). It is an environmental worldview that recognizes “the values that inhere objectively in nature independently of human wants, needs or desires” (Nelson, 2008); and it finds its roots in the work of four western and anti-anthropocentric philosophers: George Sessions, David Rothenberg, Warwick Fox, and especially to Arne Naess (Nelson, 2008). In fact, it was Naess who coined the term ‘Deep Ecology’ in a famous essay published in 1973, where he distinguished his deep and long-range view from the shallow perspective of mainstream environmentalism.

Deep Ecology in the Venetian Lagoon

The Deep Ecology movement promotes two basic principles: Biocentric Egalitarianism and Metaphysical Holism. The first one considers that all organisms and entities have equal intrinsic value, as opposed to the anthropocentric worldview which reserves this respect and veneration mainly to other fellow men. As Naess states in his famous essay, “to the ecological field-worker, the equal right to live and blossom is an intuitively clear and obvious value axiom. Its restriction to humans is an anthropocentrism with detrimental effects upon the life quality of humans themselves” (Naess, 1973). The second principle states that by way of direct experience, humans can recognize their “own ecological interconnectedness with the lifeworld in all its plenitude”, and that “the biosphere does not consist of discrete entities but rather internally related individuals that make up an ontologically unbroken whole” (Nelson, 2008). In other words, Metaphysical Holism is about selfrealization: if one understands that all living beings have the same intrinsic worth, one finally recognizes that there is no divide between the human and non-human realms.

Fig. 16 Arne Naess (1912 - 2009) , the Norwegian philoshoper who coined the term ‘Deep Ecology’​ in 1973 (Retrieved from: https://www.telerama.fr/ sortir/arne-naess-etait-une-figure-rafraichissantedans-la-maniere-de-penser-l-ecologie,156853.php).

It must be said that there are many shades of green among deep ecologists, especially regarding the principle of biocentric egalitarianism. According to many environmentalists, Deep Ecology is useless once conflicts arise because of this principle. As Michael Nelson says in the Encyclopedia of Environmental Ethics and Philosophy, “if all organisms are of equal value, then there is no basis upon which to make prescriptions because the kind of value distinctions necessary for evaluating the moral situations of environmental ethics are deliberately disqualified” (Nelson, 2008). Paraphrasing an example made by American philosopher Bryan Norton, a silverback gorilla or a giant panda cannot be treated equally with the pigeon; “not, at least, on a reasonable environmental ethic” (Norton, 1991). This is why some philosophers and environmentalists like Norton, Baird Callicott, and Warwick Fox, have moved beyond this principle. However, Arne Naess had already recognized in 1973 that biocentric egalitarianism cannot become a dogma in itself, “because any realistic praxis necessitates some killing, exploitation, and suppression” (Naess, 1973). In any case, for the construction of the scenario and to frame the design explorations in the Venetian Lagoon, a non-dogmatic standpoint will be taken from and within Deep Ecology.

Flux and Reflux in the Venetian Lagoon

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Fig. 17 Nowadays, no sediments are brought in by the rivers because they were diverted by the Republic of Venice since the Middle Ages. In addition, the outflow of sediments from the lagoon is greater than the inflow that waves bring back from the sea, especially after the construction of the jetties at the inlets by the end of the XIX Century.

Fig. 18 In a business as usual scenario where nothing is done to change the existing sediment balance in the lagoon, it will inevitably become deeper over time. Sea level rise, along with the erosive processes that take out the sediments of the lagoon floor, will make the lagoon disappear. It will cease to be a recessed coastal body of shallow brackish waters, and will become a saltwater branch of the Adriatic Sea.

Fig. 19 If we renaturalize the diverted rivers, they will bring freshwater and sediments to the Venetian Lagoon once again. In addition, if we demolish the jetties and the breakwaters at the Chioggia, Malamocco and Lido-San Niccolò inlets, we will restore the balanced exchange of sediments between the lagoon and the sea.

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Fig. 20  A diagram that shows the Egocentric Lagoon as it is today, artifically controlled by man and with little consideration for other forms of life.

All the anthropic projects that have re-shaped the territory over centuries have altered the dynamics of natural processes in the Venetian Lagoon (Source: made by the author).

The Biocentric Lagoon To shift from an egocentric lagoon towards a biocentric one, a fundamental starting point consists in recognizing the intrinsic value of the lagoon ecosystem, of its flora and fauna, and of the role played by natural processes in the regulation of life. From the moment in which the Republic of Venice decided that the tributaries should be diverted to prevent the lagoon from silting up, human wants, needs and desires have prevailed over nature. Nowadays, no sediments are brought in by the rivers; and in addition, there are more sediments going out than those that the waves are able to bring back into the lagoon. In a business as usual scenario, where nothing is done to change the unbalanced sediment exchange, the Venetian Lagoon will inevitably become deeper over time. But if this trend is also combined with sea level rise, the lagoon will disappear. It will cease to be a recessed coastal body of shallow brackish waters, to become a saltwater branch of the Adriatic Sea. In other words, if this egocentric instrumentalization of non-human nature does not change, the flourishing of both human and non-human life will be radically compromised.

If we renaturalize the diverted rivers and allow them to discharge once again into the Venetian Lagoon, an input of freshwater and sediments could help counterbalance the effects of sea level rise. The construction of a series of hydroelectric dams in the Alps throughout the XX Century has constrained the volume of sediments carried further downstream; but there is still a considerable amount of fluvial sediments that could play an important role in the restoration of natural processes, and this can be proven by monitoring the constant growth of Cavallino-Treporti during the last century (Bozzato et al., 2014). Cavallino-Treporti has doubled its surface because the jetty at the Lido inlet blocks the sediments brought by the Sile River alone. If rivers discharge freshwater and sediments once again into the lagoon, siltation will inevitably take place. But this is precisely what is needed to counterbalance sea level rise, especially if the preservation of a brackish and shallow water ecology is desired.

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Deep Ecology in the Venetian Lagoon

Fig. 23 As an environmnetal compensation project, the Consorzio Venezia Nuova has built over 1.600 hectares of new velme and barene in the Venetian Lagoon. These artificial marshlands will help to mitigate the erosive processes that are currently deepening the lagoon floor. But they will also compensate the large surfaces of barene that has been lost in the lagoon over centuries, especially after the construction of the inlets, the port, and the Vittorio Emanuele and Malamocco-Marghera canals (Retrieved from: https://www. mosevenezia.eu/my-product/recupero-morfologico-barene/#prettyPhoto).

Fig. 24 The restoration of salt marshes (barene) and shallow waters (velme) in the Venetian Lagoon will ensure the rich biodiversity that currently exists in the lagoon ecosystem. But the creation of these large artificial surfaces will also help to restore a balanced exchange of sediments between the lagoon and the sea without compromising the depth of the lagoon floor (Retrieved from: https://www.mosevenezia.eu/my-product/recupero-morfologicobarene/#prettyPhoto).

Fig. 21 Aerial view of an artificial marshland, already consolidated with endemic vegetation, in the southern part of the Venetian Lagoon. These large surfaces of barene are multi-functional by nature, since they create new space for flora and fauna, allow a balanced exchange of sediments between sea and lagoon, and mitigate the deepening of the lagoon floor. But they will also create the conditions to build on top a flexible system of dikes to protect Venice against sea level rise (Retrieved from: https://www.mosevenezia.eu/my-product/recuperomorfologico-barene/#prettyPhoto).

Fig. 22 A system of small dikes (such as this one in the outskirts of Lio Piccolo) separate the artifically-controlled waters of the fishing valleys from the surrounding salt marshes. Dikes like these were built to create more suitable conditions for the cultivation of fish, in man-made ponds that could be managed independently from the tidal fluctuations of the lagoon. If such a system of dikes is built on top of a green belt made of artificial barene, we may be able to protect Venice and the lagoon ecosystem -at the same time and in a resilient way (Source: photograph taken by the author).

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In addition, the jetties and breakwaters at the Chioggia, Malamocco and Lido-San Nicolò inlets should be demolished. As described above, these hard infrastructures have altered the exchange of sediments between the lagoon and the sea, a natural process that takes place with the tidal fluctuations every day. A ‘funnel-effect’ is making the outflow of sediments greater than the inflow that comes back from the sea, accelerating –along with many other factors– the deepening of the Venetian Lagoon. By demolishing these hard infrastructures, a balanced exchange of sediments will be restored. Furthermore, the perpendicularity of the jetties and the groins vis-à-vis the shoreline towards the sea is an obstacle to the formation of a natural dune succession (McHarg, 1971). So it is fair to imagine that by demolishing these infrastructures we are also creating better conditions for dunes to defend life inside the lagoon. As for the fishing valleys, it has been said that there is a debate among scholars regarding their real impact on the hydraulic dynamics of the lagoon.

Nevertheless, a biocentric approach should consider the possibility of giving back to nature some of these artificially-controlled and productive surfaces, if further analyses deem it necessary.

In a biocentric lagoon, the existence of Porto Marghera and the touristic cruise terminals should to be banned. The sensitivity around this topic is comprehensible because it has strong political, economic and social implications. But the wave action of the big ships that enter the lagoon has been accelerating the erosion processes of the lagoon floor; and in combination with the ‘funnel effect’ of the inlets, the existence of big ships is contributing to the disappearance of the lagoon (D’Alpaos, 2010). The Port of Trieste is an alternative for the port activities, and there are plenty of choices for the cruise ships along the shores of the Adriatic Sea. It is clear that these actions will have a tremendous impact on the economy of the city and the whole region. But then again, Deep Ecology fosters the coexistence of different forms of life, and will never encourage an activity that entails the inevitable destruction of the natural environment.

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Fig. 25 Diagram of an unbuilt proposal made in 1566 by Alvise Cornaro, which aimed to build a wall around Venice to defend it. Cornaro was in favour of letting the rivers silt-up the lagoon, so that new land could be created for agriculture (Retrieved from: https://pages.shanti.virginia.edu/Venice_11Sp_ ALAR/research/water-walls-water/).

Fig. 26 A diagram that visualizes the possibility of a Biocentric Lagoon, in which natural processes regulate life once again in the Venetian Lagoon.

Rivers are renaturalized and discharge both sediments and freshwater into the lagoon, the port has been moved out, the jetties and the breakwaters at the inlets have been demolished, and large surfaces are given back to nature to allow the creation of new velme and barene (Source: made by the author).

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Finally, the topic of Venice needs to be addressed. During the design explorations it became evident that Venice cannot be saved with a resilient approach, nor by making use of natural processes alone. Venice can only be saved with resistance.

If a dogmatic Deep Ecology approach is taken –in other words, one in which all organisms and entities have the same intrinsic value– Venice will be lost to sea level rise. But as Warwick Fox argues, this egalitarianism is useless in any realistic praxis once conflicts arise (Fox, 1984), and for this reason it is more helpful to look beyond this restrictive and normative standpoint. Paraphrasing Bryan Norton – once again–, the 120.000th Italian village cannot be treated equally with the city of Venice. The question is: can we protect Venice with a resistant strategy that could also contribute to the flourishing of non-human life? Following this line of thought, the idea of protecting Venice with a green belt of artificial islands and marshlands was born. Inside this green belt a number of historic islands that have always been associated to Venice –such as Murano, La Certosa and Sant’Erasmo–could also be protected with small and flexible dikes built on top of this green belt. They would be connected with one another, and a system of locks and pumps will help to control the level and the quality of the water inside.

Compared to other forms of resistance, the artificial green belt will create the conditions for a ‘softer’ dike system that could be very similar to the one that has been implemented in the fishing valleys. But more importantly, this system of dikes, locks and pumps will not only be useful for the preservation of Venice. These large surfaces of barene are multi-functional by nature: they will create new space for endemic flora and fauna, they will compensate the loss of barene caused by man over centuries, and they will mitigate the deepening of the lagoon floor by improving the conditions for the exchange of sediments between marshlands and the lagoon floor. The quantity –and the quality– of the ecosystem services delivered by the green belt is extensive; but the important aspect that should be highlighted is that it will be useful for man but also for many other forms of non-human life. The problem of how to protect Venice from sea level rise has been reduced from the scale of the lagoon to the scale of the green belt. And even though it is a resistant strategy, it comes from an ecological understanding of the problem.

We could summarize the Deep Ecology strategies that can be implemented in the Venetian Lagoon in the following list: 1. External sediments and greater amounts of freshwater should be brought once again into the Venetian Lagoon.

2. The diverted tributaries must be renaturalized in order to let them discharge once again into the lagoon.

3. The jetties and breakwaters built at the Malamocco, Lido and Chioggia inlets must be demolished to allow a balanced sediment exchange between the lagoon and the sea. But also to create better conditions for a natural dune succession.

4. Some surfaces occupied by fishing valleys could be given back to the Venetian Lagoon.

5. Porto Marghera and the touristic cruise terminals need to be banned from the Venetian Lagoon.

6. Venice and other important areas can be protected with a green belt of artificial islands, connected by small and flexible dikes built on top of the new land.

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Fig. 27  The peninsula of Cavallino-Treporti as it is today, in between the Adriatic Sea and the Venetian Lagoon (Source: made by the author).

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What are the consequences of this scenario in Cavallino-Treporti?

Cavallino-Treporti lies in a vulnerable position in the context of sea level rise, in between the Venetian Lagoon and the Adriatic Sea. Two different ecosystems meet in this peninsula and merge into a landscape that has been shaped by the interaction of natural processes and human occupation over centuries. For the construction of the scenario at this intermediate scale, several visualizations were made to understand the spatial consequences of different sea levels. These explorations evidenced that in general, the territory of Cavallino-Treporti is more or less prepared to cope with a sea level rise of 50 centimeters. But they also showed that the impact of higher sea levels may be dramatic, submerging half or more than two thirds of the entire peninsula. With a sea level rise of 80 centimeters, but also considering the tidal fluctuations that can make the level rise up to 150 centimeters on a regular basis, the peninsula will disappear and give way to a renewed archipelago of islands connected by a landscape of salt marshes. The visualization of this scenario may be shocking, but curiously it is very similar to the landscape that existed before the construction of the jetty at Punta Sabbioni in 1888.

Deep Ecology in the Venetian Lagoon

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Fig. 29 Towards the sea, the dunes are the main element of the landscape.

Towards the lagoon, marshes were dried up and occupied with a complex system of dikes, protecting the land from the high tides and connecting one village with the next. Controlled surfaces of water -the fishing valleys- were integrated to the occupied land, forming a series of productive units. In between the dikes and the dunes there farms that struggle to survive and large camping villages. Sandy soils, high levels of salinity, and the lack of freshwater make agriculture difficult and expensive. And the camping sites along the dunes are in conflict with the health of a natural system that may be decisive for the future of Cavallino.

Fig. 30 If the sea level rises 0.5 meters, only 5% of the buildings in Cavallino Treporti will be lost. The dike system that was built over centuries in the island to resist the tidal variations of the Venetian Lagoon can cope very well with such a rise of the sea level. Still, some parts need a reinforcement to adjust themselves to the new permanent pressures. The landscape has changed in a very subtle way. Even though Cavallino is still connected to the main land and its people remain very much dependent to car mobility, the ancient fishing valleys inside the lagoon have disappeared. The hamlet of Lio Piccolo, once connected to Treporti by a long dike, has become an island.

Cavallino-Treporti - 1.0 m SLR

Cavallino-Treporti - 1.5 m SLR

Fig. 28 In Cavallino, 55% of the built fabric will be lost if the sea level rises 1 meter. The historical towns of Cavallino and Treporti will now be underwater, but they will remain visible and livable to a certain degree, because they are standing on top of shallow salt marshes. Many of the small centralities that spurred in the 20th century on top of the sandy deposits brought by the Sile River still stand on dry land. Ca’ Savio, Ca’ Pasquali, parts of Ca’ Ballarin and most of the camping sites are now the ‘prime land’ for real estate development. People can only move by water, because the connection with the main land has been lost.

In Cavallino, 80% of the built fabric will be lost to a 1.5 meter sea level rise. Only a small part located over the higher features of the sandy deposits will remain, becoming enclaves on small islands on the Adriatic Sea. A new landscape of salt marshes will also exist, becoming visible and connecting the islands only when the tides are low. Once again, boats become the most important mode of transportation for the people of Cavallino-Treporti. They maintain a strong relation with the inhabitants of Lido and with the remnants of old Venice, the closest islands they have since the main land is now further away.

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Understanding the Interaction between Culture and Nature

Fig. 31 Bathymetric chart of the Venetian Lagoon by 1809-1811, made by the napoleonic captain Augusto Dénaix (Retrieved from: http://www. silvenezia.it/?q=node/56).

Fig. 32 The jetty of Punta Sabbioni, at the northern part of the Lido inlet, has blocked the sediments brought by the Piave and Sile rivers since its construction. This has doubled the surface of the territory of Cavallino-Treporti in 130 years (Source: photograph taken by the author).

Towards the sea, the succession of dunes becomes the main element of the landscape. By 1866, before the jetty that shapes the northern part of the Lido inlet was built, the villages of Cavallino and Treporti were separated from one another by large surfaces of marshes and grassy fields behind this natural sandbar. In fact, this long stretch of dunes was the element that linked both human enclaves together (Bozzato et al., 2014). The sandy sediments brought by the Piave and the Sile rivers where constantly washed away and pushed once more towards the shoreline by the currents and the winds of the Adriatic Sea, creating a natural succession of dunes.

But the construction of the dike in 1888 changed the landscape forever by blocking the conveyance of these sediments, creating new land, and doubling the surface of the territory over the course of 130 years (D’Alpaos, 2010; Bozzato et al., 2014). A man-made infrastructure, along with natural processes, created the conditions for an agricultural economy that did not exist before.

Towards the lagoon, marshes were dried up and made habitable with a complex system of dikes already since the Middle Ages, protecting the land from the high tides of the lagoon but also connecting one village with the next. This timeconsuming and labor-intensive process of constructing the territory finally created an archipelago of human enclaves within the Venetian Lagoon. Controlled surfaces of water –the fishing valleys– were integrated to the dried and occupied land to form a series of productive units. The hamlet of Lio Piccolo, to the north of Treporti, may very well be the most evocative of these man-made landscapes. By the end of the XIX Century, the construction of a long and robust dike along Canale Pordelio also improved the conditions for the inhabitation of an extensive stretch of land, all the way from Treporti to the town of Cavallino (Bozzato et al., 2014).

In between the dikes of the lagoon and the dunes of the littoral, there are many small-scale farms that were once very productive but that today are struggling to survive. The flourishing of this agricultural economy is closely linked to the construction of Via Fausta, inaugurated in 1929. This infrastructure –a major road over a dike that connects the peninsula with the mainland– marked an important benchmark in the shaping of Cavallino-Treporti. It integrated the scattered villages, fought the spread of malaria and created new land for agriculture (Bozzato et al., 2014). In other words, it created the spatial conditions for the occupation of the sandy soils that up to the present day continue to accumulate after the construction of the jetty. But over time it has become evident that sandy soils, high levels of

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Deep Ecology in the Venetian Lagoon

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Fig. 33  Diagrams that illustrates the evolution of Cavallino-Treporti over time, especially after the construction of the jetty at Punta Sabbioni (Source: made by the author).

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salinity, and the lack of freshwater make agriculture difficult and expensive in Cavallino-Treporti, to say the least. These may be some of the reasons that explain the decline of agriculture in recent decades –along with other factors more related to the global economy of course. They may also explain the shifting of an agricultural economy in the municipality towards a touristic one, very dependent on camping villages along the shoreline that bring over six million tourists during the summer season. But then again, the camping sites along the dunes are in conflict with the health of the dune succession. And this natural system may be decisive for the future of Cavallino-Treporti in the context of sea level rise. It is evident that this is a territory full of contradictions and in a very vulnerable position; one in which design research and scenario construction may be useful to better understand the possibilities for a more sustainable future.

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Fig. 34 Three zooms were studied in depth to understand the consequences of this scenario in Cavallino-Treporti, and to learn from the design explorations (Source: made by the author).

The description of the territory that will follow may seem dystopian to many, but in truth it is nothing more than the result of a coherent sequence of hypothesis that began at the scale of the Venetian Lagoon. As Paola Viganò states in Territories of Urbanism, “the scenario is a collection of hypotheses that investigate the future and allows us to address and discuss the future” (Viganò, 2016). In Cavallino-Treporti no one is discussing the risks that climate change will bring –much less the possibilities or potentialities. So it is fair to imagine that the lessons we may learn from these explorations at the local scale could be useful in the future for further research.

Three zooms were studied to understand the consequences of this scenario in Cavallino-Treporti: one will be located on the dry and sandy ‘highlands’ along the MOSE, close to Punta Sabbioni; another on the new shallow marshlands of the back bay, close to Ca’ Savio; and a last one on the grounds of the Camping Village Marina di Venezia, along the shoreline. This last zoom was chosen to be explored more in depth, since the actors and the conflicts they pose are unquestionably the most important in the territory.

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Fig. 37 Zoom 1 - The Back Bay. The first zoom focuses on a residential area behind a natural dune succession, close to the Amalfi Battery and between the Camping Village Marina di Venezia and the Camping Ca’Savio (Source: Google Earth imagery).

Fig. 35 Zoom 1 - The Back Bay. If the sea level rises 1.00 meter, the dry land of the backdune will become a back bay with shallow marshlands. Some buildings could be retrofitted to remain habitable in these extreme conditions (Source: developed by the author).

Fig. 36 A section that illustrates how the existing structures may be recycled, allowing people to adapt and to continue living there under new conditions (Source: made by the author).

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Fig. 38 Photomontage that shows the possible coexistence of some buildings inside the new oak and manna ash forest (Source: made by the author).

Fig. 39 Permacultural practices between the MOSE barrier and the new endemic forest, on the sandy ‘highands’ of Punta Sabbioni (Source: made by the author).

Fig. 40 The new marshlands of the back bay will be permanently flooded with at least 50 centimeters of brackish water. But the tidal fluctuations can make this level rise on a regular basis, making the ground floors of most buildings unhabitable. But life in the upper floors is still possible, and clam and oyster cultivation can take place in this renewed landscape (Source: made by the author).

Zoom 1 - The Back Bay In Cavallino-Treporti, more than half of the built fabric will be lost if the sea level rises 1 meter. Only 30% of the population will be able to keep living there, and the territory will become an island since the connection with the main land has been lost. Most of the built fabric will now be underwater, but certain buildings will continue to remain livable because they will be standing on top of shallow salt marshes -especially the tall ones. This barene landscape towards the renewed lagoon will fluctuate with the tidal movements, so retrofitting will be needed in the existing structures to resist salinity if people are to continue living under these conditions. The ground floors will become storages, and exterior staircases will connect the upper floors to a network of elevated walkways and common public spaces that now stand over the shallow waters.

Zoom 2 - The Highlands Many of the small centralities that spurred in the 20th century will also remain habitable, as they were built on the sandy ‘highlands’ of the peninsula. Nevertheless, the dynamics will change completely, forcing everybody to think beyond their individual plots and to engage in a more collective and sustainable way of life.

Common effort will be needed to harvest water, produce food and energy, manage wastewater, garbage, etc. People will only move by bicycles, boats or by foot. One of the best examples of how the individual logics of parcelation will change can be seen on the permaculture terraces built along the slopes of the highlands. They are the most suitable land for all.

Zoom 3 - The Sandbar The dune succession along the littoral will structure and defend what is left of the territory, maybe even creating new land over time. The people of Cavallino-Treporti will need to adapt and live their lives in an ever-changing landscape that depends on natural processes, and for this reason human presence will need to be seriously managed along the shoreline. By doing so, the dune succession will be able to develop and protect those who will stay. The structures of the camping villages will be recycled to give way to new and more sustainable economies like agroforestry, suitable for a territory where land is scarce and valuable. The former touristic peninsula will become the nursery for Venice.

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Fig. 42 Zoom 2 - The Highlands. The second zoom focuses on the built fabric along the Lungomare Dante Alighieri and the old jetty recently reinforced by the MOSE project. These are the ‘highlands’ of Cavallino-Treporti, since some features can reach even 4.00 meters above sea level (Source: Google Earth imagery).

Fig. 41 Zoom 2 - The Highlands. Even if the sea level rises 1.00 meter, the sandy ‘highlands’ along the MOSE will remain dry and safe. But life and the spatial character of this area will probably change nevertheless, since food and basic services like water and energy must be self-supplied by the community in a decentralized way (Source: developed by the author).

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Fig. 43 The different stages of a natural dune succession, according to Ian L. McHarg. In the Venetian Lagoon, the removal of the jetties at the inlets and of the perpendicular groins along the shoreline, will allow this natural process to take place once again and without constraints (Source: made by the author, by retracing and modifying the diagrams published in Design with Nature by Ian L. McHarg).

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The Dune Succession along the Littoral As described above, the structuring element of the littoral is constituted by the natural dune succession. These dunes have been formed over time, with sandy deposits brought by the Sile River (Bozzato et al. 2014) and pushed towards the shoreline by natural processes that are under the control of waves and wind. Today, but also in the new landscape that is being explored in this scenario, the dune succession represents the first and most important system of defense towards the sea, “accepting the waves but reducing their velocity and absorbing the muted forces” (McHarg, 1971). But it must be understood that the sandbar is a natural system of defense, and therefore it is not unalterable nor unbreachable. As Ian McHarg states in Design with Nature, the configuration of the sandbar will change in response to hurricanes and heavy storms; and the sea will sometimes cross over the dunes, flooding and filling the backdune area (McHarg, 1971). In the new archipelago of Cavallino-Treporti, the knowledge that the remaining islands are not a certain land mass is particularly important. The shape of the archipelago will be unstable and dynamic, “continuously involved in a contest with the sea” (McHarg, 1971). Moreover, the relative stability of the land behind the dunes will depend on the health of the whole succession.

Deep Ecology in the Venetian Lagoon

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Fig. 45  Zoom 3 - The Sandbar. The third zoom focuses on the dune succession along the shoreline and on the infrastructure of the largest camping site of the littoral: the Camping Village Marina di Venezia (Source: Google Earth imagery).

Fig. 44  Zoom 3 - The Sandbar. If the sea level rises 1.0 meter, the health of the natural dune succession along the shoreline becomes more important than ever. It will be decisive for the protection of what is left in Cavalino-Treporti, and it may be able to create new land over time. But for this to happen, some sacrifices must be made in the grounds of the existing camping sites (Source: made by the author).

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Fig. 46 Some photographs that illustrate the different habitats of a natural dune succession.

From the primary dunes with their grasses to the inter-dune wetlands with their saltwater reeds; from the secondary dunes covered with moss, shrubs and small trees, to the tertiary ones consolidated with a woodland of endemic species (Source: photographs taken by the author).

Fig. 47 The flora and fauna of a healthy dune ecosystem is very rich. Vertebrates and invertebrates coexist in different habitats along the transect, vegetated by a variety of grasses, reeds, shrubs and trees (Source: made by the author).

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But the presence of large camping sites along the shoreline is in conflict with the health of the dune succession. In fact, the width of the primary and secondary dunes in front of the camping villages seem narrow and fragile when compared to the natural formations that exist along the shoreline. The reason lies in the fact that human presence is only tolerated in certain parts of the succession. If we make a section across the dunes a number of environments will be revealed, each one with a different role. Opportunities, limitations and even prohibitions will vary from the beach to the embryonic dunes, from the primary dunes to the inter-dune wetland, and from the secondary dunes to the woodlands of the backdune. Mainly because of the differences among plant associations, as a result of their exposure to winds and salt-water over time. A primary dune will never stabilize nor protect the land behind if the pioneer grasses that rise from the sand cannot thrive. They need to extend their roots below the ground in order to grow and entrap the sand that is blown by the wind to enlarge the dunes. But as McHarg strongly emphasizes, “sedge and marram succumb to man” (McHarg, 1971). So if tourists from the camping sites must go to the beach, they need to get there with elevated walkways that do not interfere with the dynamic processes of dune formation.

In the new littoral of Cavallino, especially in the context of sea level rise, it becomes indispensable to strengthen the dune succession. This means that the conditions for dunes to grow and thrive need to be created, and that some changes need to be made. Ian McHarg reminds us that groins –or any other tangential constructions along the shoreline for that matter– interrupt the littoral drift and limit the volumes of sand that supplement the dunes (McHarg, 1971). This only adds to the list of reasons that justify the demolishing of the jetties at the three inlets of the lagoon, and of the smaller groins that are perpendicular to the shorelines of Cavallino, Lido and Pellestrina. Their removal will finally allow for the natural process of dune formation to take place without constraints, making the dunes wider and higher over time. But this intervention must be accompanied by the construction of elevated bridges across the primary and secondary dunes, which are very vulnerable to trampling and human occupation. Otherwise, the growth of marram grass and the subsequent accumulation of sand will not take place.

Deep Ecology in the Venetian Lagoon

Fig. 48 A photograph that illustrates the state of the camping sites within the backdune woodlands during the winter season (Source: photograph taken by the author).

In some cases, the downsizing of the camping villages will also be required to create more room for the dunes. But it must be said that most of these camping sites have been built on the backdune area, behind the second line of defense constituted by the belt of secondary dunes. And that in general their presence can be tolerated under certain conditions, since the backdune “reveals a more permissive location and this is perhaps the most suitable environment on the sandbar for man” (McHarg, 1971). It is the flattest and widest environment of the sandbar, as well as the oldest.

Over time, the embryonic dunes along the beach grow marram grasses, entrap sand, and turn into primary dunes. But as the forces of wind and waves extend the beach and create new dunes in front of them, these primary dunes keep growing and are vegetated with mosses, shrubs and small trees. As time passes, this natural process of sand accumulation keeps extending the beach. As a result the first dune belt has been distanced from the sea, and its exposure to wind and groundwater salinity has also changed. Conditions have finally been created in this backdune area for trees to grow in a more hospitable environment. Here the camping villages have long benefited from “the most delightful, diverse, safe and tolerant environment” of the dune succession (McHarg, 1971).

But the woodlands on which some of these camping sites are located have been planted by humans with invasive species. Although the acceleration of the stabilizing processes may be positive, it should be done with the appropriate vegetation.

In The sustainable tourist’s guide to the coastal environment –a document made by the Veneto Region for SHAPE, a pilot project framed inside the Natura 2000 network– “the coastal pine forests of Cavallino Treporti are not endemic and were planted by man in past decades to protect crops planted on recently reclaimed land against the negative effects of sea spray. This is also proven by the pine species that were used to create the plantations (the Italian stone pine - Pinus pinea, the cluster pine - Pinus pinaster and the Aleppo pine - Pinus halepensis), all of which are non-local species” (Regione Veneto, 2014). In a biocentric scenario, it is the sandbar that structures and regulates life. And if humans must coexist in this renewed environment, they must adapt to the natural system instead of forcing it to meet their needs. Woodlands may protect the crops, but this should not happen at the expense of other forms of life. “While the coastal pine forests may be very valuable from a landscaping perspective, from an environmental perspective they are rather shoddy (...). The extensive accumulation of pine needles on the forest floor, which do not decompose, suffocates and trivialises the undergrowth. The end result is that the pines stand alone and become a kind of monoculture” (Regione Veneto, 2014).

For this reason, the invasive species that have been planted in the camping villages should be progressively replaced with the endemic shrubs and trees that grow in this particular plant association –oak trees and manna ash, among others.

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Fig. 49  The different stages of the transformation of the Camping Village Marina di Venezia over time. The character of the existing camping site will change, and its size will be reduced (especially along the shoreline and in close proximity to the secondary dunes). There will be more space for the dune succession to take place without constraints, and the forest will be replaced with endemic species little by little (Source: made by the author).

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Evolution in Time To rethink the shoreline means to create the spatial conditions for dunes to grow without constraints, for the free passage of fauna from one habitat to another, and the restoration of the endemic vegetation that exists in other successions of the Adriatic Basin. This requires the construction of soft and flexible structures, so that humans can enjoy the highly tolerant beach without endangering the evolution of vulnerable habitats; but also the reconceptualization and the downsizing of the camping sites. All forms of life can coexist in this renewed landscape, from the woodlands of the backdune to the white dunes along the beach, but for this to happen the shoreline must be managed properly. Naturally, new questions arise from this scenario. If the camping villages are in conflict with the health of the dune succession, and if the sandbar has a major role in the defense of the territory, should they even exist? And knowing tourism is the main economic activity in CavallinoTreporti today, what will the inhabitants do if the camping sites disappear?

Deep Ecology in the Venetian Lagoon

2020 Today, the presence of the Camping Village Marina di Venezia creates a number of problems to the natural dune succession of littoral. Human presence, and the value humans put to the beach over other habitats like the white and grey dunes, has narrowed the existing sandbar to half of its natural width (from 150 meters to less than 70 in average). The grey dunes –another name given to the secondary dune belt, because of the greyish color that characterizes the nutrient-rich mosses that grow on top– are constantly managed by the owners of the camping village to avoid the intrusion of sand into their facilities. This has made the secondary dunes look like an artificial dike, when in truth they are natural sand hills artificially controlled by humans. On the backdune, the woodland under which roulottes park and tents are installed is constituted by species of trees that are not endemic to a dune succession. Pines and other invasive trees substitute the manna ash and the mixed oak forest that would naturally grow there.

2030 In this first stage, a strip of the camping village is given away for the dunes to bury.

In addition, one third of the invasive species of trees that used to exist have been cut-down and replaced with a first generation of endemic trees –white oaks, holm oaks, english oaks, and manna ash. This has created more than 150 meters of free space for the dunes to grow in width and height over time. The line of trees that has remained in the front, towards the beach, blocks and traps the sand blown away by the wind and strengthening the dune formation. What used to be a narrow primary dune and a very fragile secondary dune will finally merge to become one enlarged dune. Elevated walkways will be built over them to allow humans to get to the beach from the camping sites –which have also been reduced in size.

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Fig. 50 Schemes that illustrate the different stages of the transformation that could take place in the Camping Village Marina di Venezia. From an egocentric type of tourism that is in conflict with the dune succession, to an eco-friendly tourism scenario that can coexist with productive uses such as agroforestry (Source: made by the author).

In this second stage, new areas of the agro-camping village are left for the dunes to bury over time. This will be done by cutting-down another third of invasive trees and replacing them once again with a second generation of endemic species. Logging will be done in a non-linear way, to facilitate the connection of the woodland of Punta Sabbioni with the one of Ca’ Savio (westward and eastward of the Camping Village Marina di Venezia). The first generation of endemic trees has grown, giving way for the spontaneous growth of endemic shrubs and new trees. Primary dunes will be formed once again in front of the previous ones, and the beach will probably grow by reclaiming new land from the sea. Shrubs and small trees will begin to grow over the secondary dunes. And some parts of the elevated walkways will need to be rebuilt, since the landscape and the form of the dunes has changed.

2050 In this third stage, the endemic vegetation planted on earlier stages of the process has grown considerably, consolidating the backdune woodland and improving the health of the entire succession. The camping village doesn’t exist anymore, but sustainable tourism can still be done inside the mixed oak forest among other activities and forms of life. In the renewed territory of Cavallino-Treporti, land is scarce and needs to be managed efficiently. So integrative land uses that encourage forms of coexistence will be always preferred, especially if they enhance the natural system and create better conditions for non-human life as well. For this reason, agroforestry has become the main economic activity of Cavallino-Treporti. It has replaced tourism and is practiced inside the backdune woodland, where ecology, silviculture, agriculture and tourism can all take place at the same time.

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Fig. 52  By 2020, the existance of the Camping Village Marina di Venezia will still be in conflict with the health of the dune succession along the shoreline. The existing situation is completely egocentric, puts nature to the service of man, and endangers the life of other forms of life in the dune ecosystem. (Source: made by the author).

Fig. 51  By 2030, the dune succession has been strenghtened. The first stage of the transformation should be completed, and a strip of the camping village has been sacrificed to give more room to the dunes, allowing the succession to take place.

A third of the invasive trees behind the dunes has been replaced with endemic species, and elevated walkways have been built to get to the beach across the dunes (Source: made by the author).

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Fig. 54  By 2040, there is a sustainable camping in an oak woodland. The second stage of the transformation has already taken place, and a smaller strip of the camping site has been sacrificed once again to give even more room to the dunes.

Parts of the elevated walkways have taken a new shape, since the dunes are constantly being reshaped by the winds. The first generation of endemic trees is already bigger, and a new part of the invasive forest has been replaced with manna ash and oak trees. The transition from a touristic economy towards an agroforestal one has begun (Source: made by the author).

Fig. 53  By 2050, agroforestry dominates the backdune, on the site of the former camping village.

In this third and final stage, the new endemic vegetation has grown considerably, consolidating the dune woodland. Eco-friendly tourism can still take place inside the forest, in coexistence with other productive uses. In the backdune, ecology, silviculture, agriculture and tourism can all take place at the same time and on the same ground (Source: made by the author).

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Transition towards New Economies In this scenario, land is scarce and valuable. Land plots, monocultures, zoning, and any other form of land-use that encourages the use of the territory in an individual or non-multifunctional way, will become even more unsustainable. Sea level rise will have devastating effects in the connectivity of Cavallino-Treporti with the highly centralized infrastructures that provide the most basic needs for everyday life. As a result the provision of freshwater, energy and food, but also the management of wastewater and garbage will need to be decentralized. Communities will need to become self-reliant, and this will force them to think beyond the privileges of the individual property. A biocentric approach promotes the coexistence of different forms of human and non-human life, understanding that all of them have an intrinsic value. In this sense, agroforestry becomes an interesting alternative for Cavallino.

Fig. 55  In its most basic, agroforestry is defined as the interaction of agriculture with trees in the same space. This includes trees on farms and agricultural landscapes, but also farming in forests or along forest margins like the ones we will have in the backdune of the Littoral of Cavallino (Source: made by the author).

Fig. 56  The coexistance of eco-friendly tourism and agroforestry could be managed by a system of hedgerows, creating degrees of intimacy over a continous green carpet (Source: made by the author).

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In its most basic, agroforestry is defined as the interaction of agriculture with trees within the same space. This includes trees on farms and trees in agricultural landscapes, but also farming in forests or along forest margins like the ones that will exist in the backdune of the littoral. This intentional combination of agriculture and forestry has varied benefits, including the increase of biodiversity, carbon sequestration, soil enrichment and remediation, the support of sustainable agriculture, the optimization of rain harvesting in water-scarce contexts, and the reduction of erosion. Agroforestry could become the new economy of Cavallino, replacing progressively the tourism industry that has always been in conflict with the dune succession, and which occupies vast surfaces of land that are closed and vacant for more than seven months every single year. And since the construction of the green belt needs plenty of logs for the construction of the artificial barene, it can be said that Cavallino-Treporti will become the nursery of Venice.

Deep Ecology in the Venetian Lagoon

Looking Forward The construction of this scenario and the design explorations made by the author could seem dystopian to many at first sight, but in truth they are the result of a coherent sequence of hypothesis that began at the scale of the Venetian Lagoon.

As Luigi D’Alpaos has suggested, most of the debate around the lagoon has been centered on sea level rise, putting aside other issues that are as important and that need to be considered in an integrative way. If a resilient strategy against climate change is to be found, all the factors need to be examined altogether. But it could also be said that most of the public attention has been put on the problem of Venice, even if the repercussions of sea level rise will have a dramatic impact on many other areas within and around the Venetian Lagoon. This is why the results of this design research made in the IUAV-EMU studio, which explored the consequences of sea level rise in the context of the entire lagoon, but putting special attention on the territory of Cavallino-Treporti at the intermediate and local scales, may prove to be useful for researches and policy-makers in the future. Some lessons can be drawn from this research, and we could list them in relation to their scale:

Fig. 57  A tent with a view, illustrating the coexistence of eco-friendly tourism with agroforestry and the endemic species of a dune ecosystem (Source: made by the author).

1. The first conclusion is that in the search for a resilient strategy against climate change, and in the context of the Venetian Lagoon, sea level rise should always be considered along with the erosion processes that are currently taking place inside the lagoon. Otherwise the proposals will surely be irrelevant in the long-term.

2. The second conclusion is that Venice can only be saved with a resistant strategy.

But the search for such a strategy from a Deep Ecology standpoint showed that it is possible to reduce the scale of controlling the lagoon with artificial means, while creating more and better conditions for the preservation of other non-human forms of life. Venice can be saved without sacrificing the lagoon and its ecology.

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3. The third conclusion is closely related to the contemporary debate around engineered and natural infrastructures. The design explorations evidenced how most of the problems in the Venetian Lagoon, regardless of the scale, are associated to the construction of hard infrastructures that aimed to create better conditions for certain economic activities, and to manage them artificially to meet the needs of men. It is uncertain if humans will always be able to maintain the artificial constructs that have enabled them to occupy certain territories, and the peninsula of Cavallino-Treporti is one good example regarding this matter. Without forms of resistance, vast surfaces of land will be lost and the peninsula will become an archipelago between the lagoon and the sea. But curiously, this dramatic image is similar to the landscape that used to exist before the construction of the hard infrastructures at the three inlets. In other words: the land that man gained from nature by manipulating the territory, sooner or later will be reclaimed by nature.

4. The fourth and final conclusion has to do with coexistence –among humans but also between them and nature. In the future, and especially in coastal contexts such as the one that has been explored, land will be more scarce and valuable with sea level rise. This is a fact with strong implications, at a societal and individual scale. Land plots, monocultures, zoning, and any other form of land-use that encourages the use of the territory in an individual or non-multifunctional way, will become even more unsustainable. Forms of coexistence at the level of the community will be needed and should be promoted. This becomes an opportunity for pilot projects in many fields: from rain harvesting to energy production, from permaculture to agroforestry and eco-tourism. But coexistence also has to do with the flourishing of multiple forms of human and non-human life that share the same landscapes. The conflict between the camping villages and the natural dune succession is the best example at the local scale; but the same problem could be up-scaled, and the conflicts between the port activities and the preservation of the lagoon will come to the front. A reflection around the system of values –egocentrism as opposed to biocentrism for example– is urgently needed in the context of climate change.

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Deep Ecology in the Venetian Lagoon

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Umgiesser, G. et al. (2011). The future of Venice and its lagoon in the context of global change: From Global to Regional: Local Sea Level Rise Scenarios - Focus on the Mediterranean Sea and the Adriatic Sea (Workshop Report No. 1). Retrieved from the UNESCO Office in Venice website: http://www.unesco.org/new/en/ venice/special-themes/venice-its-lagoon/ Vergano, L., Umgiesser, G., & Nunes, P. (2010). An economic assessment of the impacts of the MOSE barriers on Venice port activities. Transportation Research Part D, 15(6), 343-349.

Grinsted, A., Moore, J., & Jevrejeva, S. (2010). Reconstructing sea level from paleo and projected temperatures 200 to 2100 ad. Climate Dynamics, 34(4), 461-461.

Bozzato, G., Busarello, S., & Santostefano, P. (2014). Cavallino Treporti: Atlante delle trasformazioni di un territorio tra mare Adriatico e laguna di Venezia: 1552-2010. Cavallino-Treporti, Venezia: Associazione Culturale Tra Mar e Laguna & Comune di Cavallino-Treporti.

Naess, A. (1973). The shallow and the deep, long-range ecology movement. A summary’. Inquiry, 16(1), 95-100.

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Fox, W. (1984). Deep Ecology: A New Philosophy of Our Time? The Ecologist 14(5,6): 194–200 MacHarg, I. (1971). ‘Sea and Survival’, in: Design with nature. Garden City, N.Y.: Published for the American Museum of Natural History [by] Doubleday & Natural History Press.

Regione Veneto & Direzione Progetto Venezia. (2014). The sustainable tourist’s guide to the coastal environment: the coastal biotopes of Cavallino Treporti. Mestre, Italy: Genesi Edizioni. Retrieved from the SHAPE pilot project website: http://www.shape-ipaproject.eu/download/listbox/WP3%20action%203.2/ The%20Sustainable%20Tourist’s%20Guide%20-%20Veneto%20Region.pdf Scarton, F., Baldin, M., & Valle R. (2009). L’avifauna acquatica nidificante nelle barene artificiali della Laguna di Venezia. Boll. Mus. civ. St. Nat. Venezia, 60, 127-141.

Goodell, J. (2017). The water will come: Rising seas, sinking cities, and the remaking of the civilized world.

Boston, MA: Little, Brown and Company.

Foscari, G. (2014). Elements of Venice. Baden, Switzerland: Lars Müller Publishers.

Viganò, P. (2016). Territories of urbanism: the project as knowledge producer (First ed.) (S. Piccolo, Trans.).

Lausanne, Switerland: EPFL Press.

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Deep Ecology in the Venetian Lagoon