Discovery Guides Areas


Venice and the Environmental Hazards of Coastal Cities
(Released December 2006)

  by Carolyn Scearce  


Key Citations



Venice: The city on the lagoon


Venice is located on Italy's northeastern coast at the northern terminus of the Adriatic Sea. The Adriatic forms a long, narrow, semi-enclosed section of the Mediterranean Sea between the eastern coast of Italy and the Balkans. Historic Venice rests on a cluster of central islands in the shallow waters of the Venice lagoon. The Venice lagoon is an inlet of the Adriatic Sea, with access to sea waters largely restricted by a series of sand bars at the lagoon's entrance. Formerly, substantial freshwater inputs flowed through the lagoon as well, but over the past several centuries most of the freshwater has been diverted to the Adriatic. Today the lagoon's water possesses a salinity level nearly as high as that of the Adriatic. Waters from the Adriatic Sea circulate through the lagoon, currently providing the primary source of lagoon waters. Without continuous exchange with the Adriatic, the lagoon's waters would stagnate and become uninhabitable for many of the organisms now residing within the lagoon.

Italian Coast
Image of Venice Lagoon; the three inlets are circled in red
The city of Venice has expanded beyond its historic boundaries and currently nearly two thirds of the region's inhabitants live on the mainland next to the lagoon. Still, slightly over a third of the city's population are spread over 118 islands within the lagoon. Lagoons, shaped as they are by opposing forces of land and sea, are changeable, geographically ephemeral landscape features. When unhampered, river flows carry sediments to their outlet and fill in lagoon areas. From the ocean side, wave forces tend to carve out the sediments and in the process transform lagoons into bays. Only when these two forces can be held in relative equilibrium can the lagoon maintain its form.

For centuries, the inhabitants of Venice have waged war on natural processes of change, in order to shape the city to their needs. Rivers, including the Brenta, Bacchiglione, Muson, Marzenego, Dese, Zero, Plave, and Sile, historically emptied into the lagoon. As early as the twelfth century, technicians diverted the lower course of the Brenta River for strategic reasons (Caniato, 2005). Over the centuries, repeated interventions with a number of the rivers followed. By the 16th and 17th centuries, city planners actively made alterations within the lagoon and surrounding environment, including building canals to help facilitate shipping and further river diversions, and building sea barriers. During the 18th century, work continued in order to improve navigability and a sea wall was built to protect the lagoon. The last couple of centuries have seen work to enhance Venice's port and commercial capacity as well as additional efforts to reduce erosion, enhance industry, reclaim land, and promote aquaculture (VWA, 2006).
map of Venice
Illustration of human alterations made to the Venice Lagoon c. 1900. Website shows major alterations to the lagoon from approximately 1300-2000

Go To The lagoon habitat

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