5.1 Coastal Protection Management
65
was not smooth and straightforward. On the other hand, current strategies differ not that
much from the way of thinking of some people around 200 years ago. The main difference
may be that today there is more and detailed knowledge available on natural processes.
Furthermore, technical development extended and improved the possibilities of protecting
people and assets against rising water levels.
5.1.2 Facts and Figures on Current Circumstances
Beforehand some facts will be shown which have been collated and published in recent
years. The intention is to spotlight the (current) situation, although it is under continuous
change. In Fig. 5.2 the flood-prone area
1 at the coast of the southern North Sea Region is
shown. The elevation along the coastal stretches of the UK, The Netherlands, Germany
and Denmark has been processed to visualize which area could be flooded if no protection
elements (e.g., dikes or barriers) would have been installed. Additional to this map in
Fig. 5.3 some figures have been collated to highlight how many people are living in the
area and how big the extension of the flood-prone area is per country.
In these countries the 5 m contour line is the main inland border based on the highest
(anticipated) water level for the extension of flooding, depending on specific circumstances
a higher contour line might be applicable. The real extension of an inundated area in case
of a dike failure would depend on the topography and on various other pre-conditions. For
example, two-thirds of the Dutch area is flood prone, and many areas which are up to 7 m
below sea level have been reclaimed from the sea by high efforts over the past centuries.
In Lower Saxony, Northwest Germany, approximately 14 % are prone to floods, if no
measures would have been taken. Storm surges in the Middle Ages extend the flood-prone
area far into the inland since men fought against the rising water. Today approximately
6000 km 2 is protected against storm surges by a dike length of approximately 1200 km in
total.
5.1.3 Historical Development
The first settlers (we don’t care why they decided to settle in an inhospitable and vulnerable area) built their houses whether on the ground or on dwelling mounds – see, for
example, Hallewas (1984); Reinhardt (1984) and van de Ven (1993). The reason why it
was possible to live on the ground in that time without any protective elements may differ,
but it is assumed that the regression of sea water enabled settling. With the experiences
1 Flood-prone area: The area at the coast which will be inundated if no infrastructure against flooding are in place, for example, dikes or sluices. The extension of the flood-prone area differs from
Member State to Member State. For example, in Germany the flood-prone area is bordered by the
5 m elevation line in the hinterland. At some coastal strips, the 10 m elevation line is the restriction,
it depends on the calculated water level the dikes should withstand.
65
was not smooth and straightforward. On the other hand, current strategies differ not that
much from the way of thinking of some people around 200 years ago. The main difference
may be that today there is more and detailed knowledge available on natural processes.
Furthermore, technical development extended and improved the possibilities of protecting
people and assets against rising water levels.
5.1.2 Facts and Figures on Current Circumstances
Beforehand some facts will be shown which have been collated and published in recent
years. The intention is to spotlight the (current) situation, although it is under continuous
change. In Fig. 5.2 the flood-prone area
1 at the coast of the southern North Sea Region is
shown. The elevation along the coastal stretches of the UK, The Netherlands, Germany
and Denmark has been processed to visualize which area could be flooded if no protection
elements (e.g., dikes or barriers) would have been installed. Additional to this map in
Fig. 5.3 some figures have been collated to highlight how many people are living in the
area and how big the extension of the flood-prone area is per country.
In these countries the 5 m contour line is the main inland border based on the highest
(anticipated) water level for the extension of flooding, depending on specific circumstances
a higher contour line might be applicable. The real extension of an inundated area in case
of a dike failure would depend on the topography and on various other pre-conditions. For
example, two-thirds of the Dutch area is flood prone, and many areas which are up to 7 m
below sea level have been reclaimed from the sea by high efforts over the past centuries.
In Lower Saxony, Northwest Germany, approximately 14 % are prone to floods, if no
measures would have been taken. Storm surges in the Middle Ages extend the flood-prone
area far into the inland since men fought against the rising water. Today approximately
6000 km 2 is protected against storm surges by a dike length of approximately 1200 km in
total.
5.1.3 Historical Development
The first settlers (we don’t care why they decided to settle in an inhospitable and vulnerable area) built their houses whether on the ground or on dwelling mounds – see, for
example, Hallewas (1984); Reinhardt (1984) and van de Ven (1993). The reason why it
was possible to live on the ground in that time without any protective elements may differ,
but it is assumed that the regression of sea water enabled settling. With the experiences
1 Flood-prone area: The area at the coast which will be inundated if no infrastructure against flooding are in place, for example, dikes or sluices. The extension of the flood-prone area differs from
Member State to Member State. For example, in Germany the flood-prone area is bordered by the
5 m elevation line in the hinterland. At some coastal strips, the 10 m elevation line is the restriction,
it depends on the calculated water level the dikes should withstand.