Coastal erosion Croatia
Vulnerabilities - Current situation
The Croatian coastline is 5,835 km long. Data on the length that is artificially protected or modified is scarce. The coastline mostly consists of carbonate rocks. These rocks are more prone to karst processes that mechanical weathering. The hinterland carbonate composition influence development of karstic relief with a poorly developed river network with a small or restricted discharge. Amounts of terrigenous material (potential beach sediments) are negligible (2).
The Adriatic Sea is microtidal with a tidal amplitude between 0.22 and 1.2 m (5). Wave heights are usually between 0.5 and 1.5 m while wave higher than 5 m rarely occur.
There are numerous gravel pocket beaches all along the coast, often serving as ports and recreational centres. The only real hazards for these beaches are the projected sea-level rise and increased storminess. Erosion of natural beaches shows that the sedimentary deficit is a general problem in some regions. Artificial beaches are created by sporadically hauling in truckloads of crushed stone. In order to prevent erosion, numerous groins have been built, which cause selective erosion (1).
About 6% of the coastal rock is flysch (alternating marls, siltstones and sandstones). This rock stretches along the entire Slovenian coast and along parts of the coast of Croatia and Montenegro. Badlands are a common erosional landscape on the flysch, and cliffed coasts evolve under destructive wave impact and subaerial weathering and erosional processes. In these rocks, rock falls occur frequently, endangering the road and beaches. These events are mitigated by constructing artificial drainage systems, stone walls and concrete sills, or utilizing protection by wire mesh and concrete. Most of these protection structures are not planned but randomly built (1).
Vulnerabilities - Future situation
The vulnerability of the Croatian coastal zone to erosion has been assessed for a sea level rise of 20 cm and 86 cm, respectively (4). At a sea level rise of 20 cm, the Croatian coast is not exposed to erosion processes. In the predominant part of the coast, the coast flooding due to the sea level increase will be experienced only in the low-lying areas, which includes the majority of small beaches. These changes will as a whole have a relatively small impact on the economic activities such as agriculture, fishery, tourist industry and the residential sector. … It is highly probable that the increase in the sea level and the resulting increase in groundwater table will not affect the agricultural activity in the low-lying coastal areas. … The sea level increase could cause saline water intrusion into the ground and surface waters in the coastal belt, and this could negatively affect the potable water supply and agriculture. The impact on groundwater and increase in intrusion are difficult to evaluate because of insufficient data, but it is realistic to expect that they will not be high.
The effects on coastal erosion and existing pocket beaches is expected to be negligible because the majority of the pocket beaches are relatively steep sand and gravel deposits and are therefore, along with most of coastline, resistant to erosion (3).
At a sea level rise of 86 cm, the increase in the sea level will have the strongest effect on erosion in the territory of the city of Nin. There is a high probability that such sea level increase will cause erosion in some other zones as well.
At a sea level rise of 86 cmexisting pocket sand and gravel beaches would be inundated, but a significant number of them would be re-established further landward under wave activity and erosion where slopes permitted. In addition, artificial beaches could be constructed within tourist complexes. Therefore, in the long term, beach inundation would probably only have minor effects on tourism (3).
The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Croatia.
- Pikelj et al. (2013)
- Sondi et al. (2008), in: Pikelj et al. (2013)
- Baric et al. (2008)
- Republic of Croatia, Ministry of Environmental Protection and Physical Planning (2001)
- Lambeck et al. (2004), in: Pikelj et al. (2013)