Coast evolution | icgc

Coast evolution

ICGC with LiDAR data monitors the coastline and possible pollutants with airborne hyperspectral sensors and satellite images

Imatge aèria d'una zona costanera amb infraestructures viàries.

Coastal areas are fragile ecosystems, but at the same time they concentrate most of the population and economic and tourist activities, in such a way that the erosion produced by storms, aggravated by the existence of ports and breakwaters that interrupt natural transport sediments, and the urbanization of hydrographic basins, among other actions that reduce the contribution of material from rivers, can cause significant damage.

Less immediate but also serious effects are those caused by the increase in sea level, decreasing the coastline, expanding the areas at risk of flooding, introducing salt water, eliminating wetlands ...

All this implies a control of these areas that allows dimensioning the actions to be undertaken, observing more or less parameters depending on the objectives: volume of material to be handled in the regeneration of beaches, classification of habitats, etc.

This control is supported by some community and international policies on coastal management and its resources, which require the availability of data to make decisions.



One method to observe the evolution of the coast would be by aerial photography, and although it would allow delimitation tasks, it would be difficult to obtain 3D data in sandy areas due to a lack of stereoscopic vision (there is no texture).

Topographic (airborne) LiDAR can be considered optimal for calculating differences on shore, although it does not penetrate water.

The current bathymetric LiDARs allow data to be obtained simultaneously above and below the water, but it is necessary that it be clear (where the waves break it is not) and the depth of less than 50 m, and also its process is complex, it can affect the human eye, and the price is higher.

With the above, it can be concluded that, if you only want to study the emerged area, the use of topographic LiDAR is preferable.

Compatible with the previous methods, the use of hyperspectral and thermal sensors could be mentioned to know the evolution of polluting elements, but they would be basically limited to this aspect.


Solution description

The ICGC technique to analyze structural changes in the territory is based on conducting LiDAR flights on different dates. As the shoreline can usually be covered with a single pass, it is an economical technique and it expands the frequency of passage to have more data, for example at high tide and low tide.

It should be noted that the ICGC applies a pass adjustment specifically developed to correct height errors that LiDAR points may have and thus achieve high precision.

From these LiDAR points, the DTMs are generated that will allow the creation of the corresponding difference model (and hence the calculation of volumes, etc.), taking into account that the coastline is drawn manually because a good algorithm to do it automatically, the same thing happening with the classification of the points that belong to the water.

The same technique is used directly for the detection of new constructions, likely to be illegal due to the special protection of coastal areas.

In addition, all this information, related to data of other types (hydrography, structures, etc.), can be used in subsequent analyzes to know the impact of certain constructions on natural processes.

Representació d’una zona costanera a partir de dades de LiDAR en dues dates diferents


A. Ruiz et al., 6th European Congress on Regional Geoscientific Cartography and Information Systems, 2009.

Aportación del lidar aerotransportado al cálculo de cambios en las playas tras temporales
A. Ruiz, Revista Catalana de Geografia, 2009.


Fulfilled projects

  • Annual evolution of the Catalan coast. Generalitat de Catalunya.
  • Evolution of Pravia beach, Astúries. INDUROT.
  • Study of the coast of Guipúzcoa. Guipúzcoa Provincial Council.
  • Regione Emilia Romagna (Italy).


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