Modelling Coastline Change of the Darss-Zingst Peninsula with Sedsim - The Baltic Sea Basin - page 295

significant feature is also common in the Fischland area. An intense water exchange
can be expected with remarkable effects for hydrography and biology. The rising sea
level also prevents the formation of a spit at the Darsser Ort. There is no sediment
accumulation visible, but a retreat of the coast. The northern forefront is smoothed.
The vertical movement of the earth's crust acts contrary to the sea level rise
in the study area, mostly. With a maximum value of 0.4 mm/year (Fig. 14.5 ) this
process has a low influence on the system. Summed up for the next 840 years, this
culminates in a maximum uplift of 0.34 m, valid for the most northeastern parts.
The results for experiment C, that includes this uplift, is shown in Fig. 14.8c .
In experiment D (Fig. 14.8d ) the extreme conditions of the storm surge from 1872
are added to the set of inputs so far. Now, the recent coastline cannot be recognized
any longer onshore but is visible as a sharp submarine ridge. From the peninsula,
only some islands remain. The Alt-Darss and a part of Fischland are still above sea
level as well as the area south of the Bock.
The comparison of the different experimental results points out a major con-
trolling effect of sea level rise for the development of the coastline, even on the
local scale. A shift of sea level not only has a direct impact because of morpholog-
ical adjustments but also influences the sediment transport system by changing the
exposure of terrain to waves.
14.6 Summary
For the area of the Darss-Zingst peninsula, experimental scenarios for the devel-
opment of the coastline during the next 840 years have been calculated with the
sediment transport modelling software Sedsim. Climate-driven parameters taken
into account are sea level change, wave regime, and extreme storm events. The
parameterization of the sea level aligns to IPCC CO 2 concentration scenarios, while
for the waves data from past decades have been extrapolated. On the geological
side, vertical movement of the earth's crust and the distribution of different sedi-
ment types are included into the modelling. These parameters have been adjusted
according to most recent maps and investigations from the study area. A digital
elevation model with a spatial resolution of 150 m serves as the structural frame.
Different parameterization set-ups have been tested. In a first approach, the
impact of waves in combination with biannual storms has been simulated. The
results of this experiment show a continuation of the recent sedimentation regime
with sediment longshore transport fromwest to east. This pattern changes drastically
if the module responsible for the simulation of sea level rise is activated. A formation
of the spit at the Darsser Ort cannot be recognized anymore, and the consolidated
coast breaks apart into some small islands. Now, the former isolated Bodden chain
is connected to the open sea by channels. By the integration of the module for
vertical movement of the earth's crust, these model results are not modified sig-
nificantly. In a worst-case scenario the sea level height from the storm surge in 1872
is superimposed. Only some areas remain above sea level, while the majority of the