Distance from the sea and coastal erosion

What we use

The 2020 coastline from ISPRA (the Italian Institute for Environmental Protection and Research), from its Coasts Portal (Portale Coste). It maps the Italian coast, 14,858 kilometres split into 99,229 stretches, from aerial photos taken between 2017 and 2020. For each stretch it says what type of coast it is (low, high, port, defence structure), whether there are defence structures such as breakwaters and groynes, and how the shoreline has moved since 2006:

• eroding: the shoreline retreated by more than 5 metres between 2006 and 2020;
• advancing: the shoreline advanced by more than 5 metres;
• stable: the shoreline moved less than 5 metres.

Licence CC BY 4.0.

How we use it

The report measures the distance between the address point and the nearest coastline. If the sea is more than 10 kilometres away the section does not apply and says so, with the distance.

Then it looks at the natural coast, low like beaches or high like cliffs, leaving ports and defence structures aside:

• the trend of the stretch of natural shoreline nearest to the property;
• how the natural coast within 1 kilometre of the nearest coastal point breaks down: how much is eroding, advancing, stable or without information, in metres and as a percentage, with a chart;
• the coastal defence structures along that stretch, for example breakwaters, groynes and reinforced river mouths.

When the nearest stretch of natural shoreline is eroding and less than 1 kilometre from the address, the section is marked "Worth considering"; otherwise it is for information. The report does not redistribute the coastline: it only shows distances and shares.

An example: in Rimini, in Via Castagnevizza, the sea is about 410 metres away and the nearest stretch of shoreline is eroding, but within the surrounding kilometre most of the shoreline is advancing (40%) or stable (36%). The report shows both.

The strip along the coast protected for its landscape is in a separate section: Landscape, wildfires and noise.

Limits

• The trend is a measure of the past, from 2006 to 2020, not a forecast. It does not account for storms or beach replenishment (sand brought back onto beaches) that came afterwards.
• For more than two thirds of the coastline ISPRA gives no trend: there the report says the trend is not indicated.
• Movements of less than 5 metres count as a stable shoreline.
• Constraints and setback zones along the coast are set out in the regional coastal plan and by the Comune (the local council).

Official page: ISPRA's Coasts Portal.