PAST, PRESENT AND FUTURE COASTAL CHANGES AND THEIR IMPACT OF
CULTURAL HERITAGE SITES: RISK MANAGEMENT AND MITIGATION
The early Holocene
retreat of the ice sheets led to an eustatic increase in sea
levels, while in Upper Holocene, the sea-level changes were
controlled by the tectonism. During the last 5000 years, the
first permanent settlements were developed and financial,
social, and cultural relations were evolved. The
geomorphological features and the physical advantages of
coastal areas were important factors for establishing
settlements. Sea-level changes often modified the
palaeomorphology of the coasts, resulting in submersion or
uplift of coastal constructions or even of entire
settlements. During the past decades, numerous of
archaeological issues, concerning the modern position of
ancient coastal settlements, have been resolved or
approached, contributing to the palaeomorphological
reconstruction of such areas.
In modern times, the
many factors that control the evolution and shaping of the
coastline are still active. These include the changing rates
in sea level rise, which, in turn, influence the nature and
the severity of coastal erosion, a key factor in
transforming the coastal landscape. Also, a wide range of
climatic conditions including atmospheric pressure,
temperature, wind speed and rainfall have influence upon the
geomorphology
of the coastline.
Climate change impacts
are functioning as risk multipliers to problems which are
already apparent. Climate stressors can directly affect
cultural heritage sites. Sea level rise threatens coastal
monuments with increased erosion and salt water intrusion.
More frequent and intense storms and flood events can damage
structures that were not designed to withstand prolonged
structural pressure, erosion and immersion.
Risks affecting cultural
heritage may stem from exposure to one or more hazards.
Therefore it is important to facilitate a holistic
understanding of risks affecting cultural heritage. This
implies that we understand the inherent link of physical
vulnerability of cultural heritage to that resulting from
social, economic and “development” processes.
Risk
is defined as “the probability of harmful consequences, or
expected losses, resulting from interaction between
vulnerability and exposure”. Therefore, the vulnerability of
the cultural heritage to climatic change and erosion is
estimated as the probability of risk. However, vulnerability
is not only a “product” but a “process” as well, resulting
from various factors, which contribute towards its change
over time. Therefore, it is needed to be assessed whether
vulnerability has increased, decreased or reinforced over
time. It is also important to understand the term “disaster”
and articulate its relationship to “risk”. Another related
issue is that human perspective for disasters is essential,
especially when dealing with cultural heritage at risk.
Comprehensive understanding of
risks can build a basis for taking proactive measures to
control these vulnerability processes so as to reduce the
anticipated risks in the future. In terms of Cultural Heritage
Risk Management, this implies a new paradigm for conservation,
which is proactive rather than being reactive and is aimed at
protecting the present of ‘the past’ by anticipating its
future.