As ruínas da cidade romana de Altinum foram localizadas em imagens aéreas graças a um período de estiagem em julho de 2007, que permitiu "ver" abaixo do solo. A cidade foi abandonada a partir do século 5º da Era Cristã por causa de invasões bárbaras. Seus habitantes moveram-se para a mais protegida posição em meio à laguna, fundando a atual Veneza.
Altinum está enterrada sob culturas de milho e soja. O estresse hídrico provocado pela seca pode ser detectado graças à radiação infravermelha próxima, sensível a mudanças no crescimento da vegetação.
A diferença na reflexão permite criar imagens com cores falsas. Cores mais claras indicam locais onde há pedras, tijolos ou mesmo solo compactado sob as plantas. As cores mais escuras revelam onde há depressões no terreno, indicando poços e canais, mesmo que cheios de sedimentos. "Nós descobrimos o mapa da cidade. Nós agora sabemos como era o tecido urbano, onde estavam os edifícios principais, monumentais, onde era a cidade, suas portas e a existência, que não se suspeitava, de um canal que cruzava a cidade e a conectava à laguna e aos rios no interior. Também achamos algumas estruturas do porto, que devia ser provavelmente o porto da cidade romana", afirma Paolo Mozzi, um dos quatro autores da pesquisa, do Departamento de Geografia da Universidade de Pádua.
Rome, July 31, Ansa - The ancient coastal town of Altinum, the forefather of Venice, has been mapped out for the first time ever by an Italian team of geographers from Padua University.Using infrared aerial photography and a 3D reconstruction method, the team has created an incredibly detailed map of the town's sophisticated architecture, picking out bridges, walls, canals and houses as well as its large public buildings such as the theatre and the forum.Altinum, now located inland 15 kilometres south-east of Treviso, was already inhabited in the first millennium BC and grew in the second century BC when it was annexed to Rome.''Until now we only knew that Altinum was there, we didn't know what it was like,'' said team leader Paolo Mozzi.''In size it's comparable to Pompeii, and Altinum is the only large Roman city in northern Italy and one of the few in Europe that wasn't buried by modern and medieval cities that rose up later. That's the reason we can see the Roman age structures of the city so well,'' he said.Mozzi said the study, published in Science, indicates the existence of a ''complex urban structure'' with ''spectacular architecture'', but most importantly shows that the ancient inhabitants had adapted to the demands of living on the lagoon.''These results show that the Romans successfully managed to exploit the watery environment many centuries before the city of Venice began to emerge on the archipelago in the middle of the lagoon,'' he said.The aerial photos of the area were taken in 2007 during a drought, which has increased the visibility of the remains of the city that lie under the ground.''We see a walled city, a theatre, an amphitheatre outside the walls, the basilica, the forum with its market, then a principle road connected to the Via Annia (the Roman road through northern Italy),'' said Mozzi.''You can also see a canal that divides the city in two and heads towards the lagoon. Considering the sea level in Roman times, that canal must have been connected to the lagoon as well as with nearby rivers,'' he said, adding that the map also suggests a protected port that would have been used by merchant ships.Altinum was destroyed by Attila the Hun in 452 AD and many of its inhabitants fled to the lagoon islands that later grew into the city of Venice.Work is under way to assess the state of the structures under the ground, although the city is thought to have been dismantled' and its precious materials removed to construct the island town of Torcello and Venice.Mozzi said excavations would be complicated but that the ongoing research will help researchers understand how much of the city is still intact.
Photo: Altinum map