Coastline
The ICGC maps the coastline within the set of products for the coastal environment of Catalonia.
The coastline is the line that marks the intersection between land and sea at a given time. This line can vary due to natural phenomena such as tides, erosion or sedimentation, as well as human interventions.
The coastlines are drawn following the land-sea boundary that is visualized in the orthoimages of the periodic photographic flights carried out by the ICGC over the coast of Catalonia. These photographic flights of the entire coastal area have been carried out annually since 2008 and biannually since 2022. The scope of these flights is the entire Catalan coast.
Coastlines are also generated from orthoimages of photographic flights that the ICGC has been carrying out since 2017, in coastal areas affected by storms
These data are used to evaluate changes in the coastline over time or due to the effects of storms, and to determine areas of sediment loss or gain to adapt coastal management to the changes.
The coordinate system adopted is the official one in Catalonia: ETRS89 reference system and orthometric heights using the EGM08D595 geoid model..
Imatge
| Geoinformation from the Cartographic and Geological Institute of Catalonia subject to a Creative Commons International Recognition 4.0 license More information |
What do we mean by coastline?
The coastline defines the boundary between surface and submerged land for a given date that approximately coincides with the origin of the altimetric reference system. In sandy areas it coincides with the limit of wet sand and more stable dry sand and in areas of rocks or breakwaters it coincides with the sea level observed at the time of capture. The swell, tides and changes in the terrain throughout the same data capture mean that this line must necessarily be an approximation, especially in areas of shallow depth and sediment accumulation such as the Ebro Delta.
The coastline is drawn through photointerpretation of the boundary between land and sea, using high-resolution orthoimages (10 or 15 cm) generated by the ICGC. These images are obtained from periodic coverage flights of the coast, allowing a detailed and precise representation of the coastline.
Resulting product
The "coastline" product is a vector file that represents the contour of the coast. Each section includes information on the type of terrain that is described by indicating one of the following typologies:
- Sand: sand on beaches regardless of grain size.
- Rock: natural rocks.
- Breakwater: Artificial rock constructions.
- Pier: port construction.
- River: line of the river's mouth into the sea.
Each section is also associated with the date on which the image used to draw it was captured. This allows the user to easily know the date associated with each segment of the coastline.
Featured use cases
Coastline - Periodic
Coastal dynamics are constantly evolving due to multiple factors, such as sediment transport, waves, changes in ocean currents, wind and human interventions, such as the construction and modification of ports, breakwaters and artificial beach regeneration. These elements directly influence the layout of the coastline, causing it to shift over time.
Having an updated coastline is essential for efficient land management, as it allows informed decisions to be made in areas such as urban planning, the conservation of coastal ecosystems and protection against extreme phenomena, such as storms and sea level rise.
Coastline - storms
Having coastlines from different periods allows us to analyze the evolution of the coastline over time. This is especially useful for studying sediment dynamics in the surface area after a storm, as it facilitates the identification of areas where sediments have accumulated or been lost. This type of analysis is essential for coastal management, as it helps to plan protection measures, beach regeneration and adaptation to the effects of climate change, such as accelerated erosion and sea level rise.
The availability of coastlines from different periods helps us to conduct studies of sediment dynamics in the surface area after a storm to evaluate areas with sediment contributions or losses.
