Monitoring of the Common Indicator 16 focuses on measuring the length of artificial coastline and its share in total country’s coastline, on a proper geographical scale. An example of artificial vs. natural coastline can be seen in example on breakwaters in Figure 2.
The monitoring of this Common Indicator entails an inventory of:
(i) the length and location of manmade coastline (hard coastal defence structures, ports, marinas. Soft techniques e.g. beach nourishment is not included.
(ii) land claim, i.e. the surface area reclaimed from the 1980’s onward (ha); and
(iii) the Impervious surface in the coastal fringe (100m from the coastline).
With regard to the coastline to be considered: the fixed reference official coastline as defined by responsible Contracting Party should be available throughout monitoring (initial, and all consequent monitoring should use the same official coastline). The optimal resolution should be 5 m or 1: 2000 spatial scale. The monitoring should be done every 6 years, and so every CP should fix a reference year in the time interval 2000-2012 in order to eliminate the bias due to old or past manmade infrastructures and coastal processes such as coastal erosion.
The length of artificial coastline should be calculated as the sum of segments on reference coastline identified as the intersection of polylines representing manmade structures with reference coastline ignoring polylines representing manmade structures with no intersection with reference coastline. The minimum distance between coastal defence structures should be set to 10 m in order to classify such segments as natural, i.e. if the distance between two adjacent coastal defence structures is less than 10 m, all the segment including both coastal defence structures is classified as artificial.