Geological Hazard Potential at the Baltic Sea and Its Coastal Zone: Examples from the Eastern Gulf of Finland and the Kaliningrad Area - The Baltic Sea Basin - page 339

increased by 1.5 times (from 16 to 24 km and from 37.5 to 55 km, respectively;
Bitinas et al. 2005 ) during the same period.
Three types of coasts are distinguished in Poland, depending on morphology and
geological structure: cliffs (101 km), barriers (380 km), and coasts similar to wet-
lands (salt marshes) (17 km). Cliff coasts suffer from mass movements; serious risks
are related to erosion of low and narrow barriers, which could be easily broken dur-
ing storm surges (Uscinowicz et al. 2004 ) . In the Pomeranian Bight, the average
shoreline retreat is in the range of 0.1 m/year along Wolin Island, 0.2 m/year along
Rügen Island, and 0.4 m/year along Usedom Island, despite huge areas of accumu-
lation between the headlands of Rugen Island, at both ends of Usedom Island and
the southeastern part of Wolin Island (Schwarzer et al. 2003 ) .
The frequency of occurrence of storm surge events along the nontidal German
Baltic coast shows a significant linear increase of 1-3 events/100 years for the last
decades. At the same time, a simulation of the last 30 years of the twenty-first cen-
tury results in only small changes in the frequency of occurrence of extreme storm
events with increased high water (Baerens and Hupfer 1999 ) .
It has been suggested that the main reason for the more intense coastal erosion
is an increase of storm events, which have caused severe damages both in the Gulf
of Finland and in the major part of the southern and the eastern Baltic Sea (Raukas
and Huvarinen 1992 , Orviku et al. 2003 ) . In many cases, detailed analysis of the
nearshore zone structure and processes gives the key to understanding of the coastal
problems (Schwarzer et al. 2003 ) .
Recent increase of construction works within the offshore areas and the coastal
zones of the Baltic Sea (new harbors, oil and coal terminals, oil and gas pipelines,
cables, and different hydrotechnical constructions) may transform common geo-
logical processes and phenomena into hazard potentials. Growing anthropogenic
activity makes the geological hazard problem very important for spatial planning
and sustainable development of the Baltic region.
16.1.1 Approaches and Methods of the Geological Hazard
Classification and Typology
The European Spatial Planning Observation Network (ESPON) requested an assess-
ment of spatial patterns and territorial trends of hazards and risks (Schmidt-Thomé
2006 ) .
The German Advisory Council on Global Change (WBGU) suggests that a prob-
ability of hazard occurrence, the extension of its damage (with the certainty of their
assessment), its location, persistency, irreversibility, delay effect, and mobilization
potential are the basis for hazard classification and characterization (Fleischhauer
2006 ) . On these grounds, it is possible to distinguish several different types of risks.
A large proportion of geological hazards and the natural processes that can
provoke them are classified as the so-called Cyclops-type risk with an unknown
probability and high extent of damage (earthquakes, volcanic eruptions, river
floods, storm surges, tsunamis, avalanches, landslides, etc.). Phenomena like the