Here is the coastline I know best. Bathymetric data is still that of the General Bathymetric Chart of the Oceans , by the British Oceanographic Data Center, with depth contours in meters. Contour zero comes from a generalization of the digital elevation model, and it is into the current sea when compared to the real coastline, so I render it to show the precision level of the data source, which is enough given the visible scale.
The Galician rias are considered in Spain an example of the way the sea and the land can relate. The sea, but what would happen if the sea were to disappear (an unlikely event) mark the landscape?. Here a substantial part of the landscape that can be seen east of Monte de San Pedro, a belvedere over La Coruña (A on map) would be at a depth lower than Hercules Tower, the Roman lighthouse of the city, inscribed in the UNESCO world heritage list.
The elevation of the tower over the current sea level is already substantially higher than the surrounding depths. On the image, you can see an approximate rendering of depth 25 m contour, as well as the height of the tower. The landscape of the area would change if the sea receded, but not just due to the absence of water, that unifies the image, as there would also be shipwrecks, rubbish and other signs of the human presence in the city over the centuries.
Every sanitation system in the world somehow ends at sea. Some systems are more sophisticated, others are less. But if your underwater pipe gets far enough from the shore, you don’t see the results… at least at first sight. It is like hiding something under the rug…
How thick the rug? On the next image, generated using the General Bathymetric Chart of the Oceans published by the British Oceanographic Data Center, you can see the depth (in meters) of the underwater spaces under the Iberian peninsula. The dark brown hues are areas less than 200 m deep (the height of the highest buildings in the peninsula). It is also a dimension previously used in a game here at metrhispanic, albeit in the opposite sense…
Metropolitan Toulouse would be underwater, just west of the new Labastide d’Anjou straits, separating the new Iberian landmass (relief shading) from the European landmass (blue contour line)
Tarbes would be the capital of the new fjord land…
Some metropolitan ranks would change… metro Barcelona would be known as metro Terrasa, and Oviedo would become the only remaining element of the large Asturian metropolitan core.
Zaragoza (upper image) and Mérida (lower image) are two historic cities with a strong roman heritage that happen to be near contour 200m, so they would be new seaports at the mouth of the Ebro and the Guadiana. In both cases the old cities would be dry… just a lucky end… but in both cases the agricultural plains of the current rivers would be largely lost.
Most of the coastal metro areas would simply dissapear under water (upper image, Lisbon). For some, the new coastline would be just a handful of islands with no links, but for others (lower image, the Artabrian gulf between La Coruña and Ferrol) the new shore would be even a bit simpler than the existing one. The summits of the coastal hills would remain, not being necesarily the most interesting thing.
Planning is somehow a narrative thing: you have to create a story that can be of interest to your audience, as to make sure they can become involved in a project that, finally, is theirs as they are the ones living there. But it can become a narrative on its own, or just a way to rediscover a space you have known for a long time, just by getting conscious of features are not aparent every day. And this is clear when you talk about large scale planning.
I once read “The stone raft”, by the portuguese Nobel writer José Saramago, a book in which the Iberian Penninsula gets cut from Europe following precisely the political borders to go for walk around the Atlantic: the Pyrennées get sharply cut along the border line, and in a given moment Andalusians flock to Malaga to see Gibraltar Rock pass along, as it keeps in its original place (well, that also happened somehow in “Hector Servadac” by Jules Verne). So I decided to think about a less violent cut (sort of…). I downloaded SRTM elevation data for the Iberian Penninsula and Europe-wide data from the European Environmental Agency. If the whole world was to see a rise in the sea level of 200 m (for whatever reason, be it climate change -whose forecasts are way inferior to this figure- or any other you can think of), the whole of Iberia would be an island… albeit a quite different in outline from what we know now.
Being coherent, this hypethesis means most of Europe would get under the sea. The Netherlands and Denmark would be mere memories, Paris, London, Berlin and Rome would also be under water, the Ruhr valley would be a great lake and most of Hungary would be a large bay.
Spain, Switzerland and Austria would be the countries in the least bad situation, as most of their territory would be untouched. What is under the 200 m contour?
In southern Malta you are told to visit the Marsaxlokk harbor, with picturesque traditional boats. On the background you can see the Delimara power station, a strategic energy asset for the islands. It may see an eyesore to many, but Malta is a book case on the issues raised in a place where the land is so scarce you cannot hide needed big infrastructures (an equivalent solar array or a group of wind turbine would be equally visible in such a small island).
The new urban harbor in Hamburg (Haffencity) is a large renewal program in which the coast transfoms, but does not reduce its artificial condition. Altough there is a will to reintroduce nature, and in some areas there are no more moored ships, the shore is still a concreteline (it probably would be quite difficult to avoid that as new buildings need some security it will stay…)
Comillas, in the northern Spanish coast. Coastal erosion can be a problem, but it can also create impressing landscapes.