Simulation der Siedlungsflächenentwicklung als
Teil des Globalen Wandels und ihr Einfluß auf den Wasserhaushalt im
Großraum Berlin
B. Ströbl, V. Wenzel, B. Pfützner (April 2003)
Possible
impacts of Global Change on the regional water balance is one of the
aspects studied in the project GLOWA-Elbe, funded by the German Federal
Ministry of Education and Research.
This study focusses on the corresponding peculiarities of Greater Berlin as an example of an
urban agglomeration. Especially regions of this kind are affected by the process of urban
sprawl accompanied with accelerated consumption of land and sealing, processes that are very
crucial for the rain-water runoff in the region.
Thus, the most relevant Global Change phenomena to be considered in this respect are changes
in climate and therewith in precipitation and evaporation on the one side and the dynamics of
socioeconomic driving parameters for the mentioned urban sprawl process on the other side.
This process can be observed and must be considered even in a country like Germany with a
more or less stable population.
The study identifies and analysizes three different regional trends of
urban development, each following a certain guideline assumption. The
trends are quantified and spatially allocated. For this purpose a
landuse simulation tool was created and implemented into a commercial
GIS package. It is described here in detail and includes a two-step
procedure: In the first step rules are defined stating each locations’s
suitability for a land use change to take place. Next a stochastic
process allocates the desired amount of change within the area of
highest suitability.
A digital landuse map for the region was compiled from different sources with special attention
to the grade of sealing and type of sewer system for urban areas. It is merged with the urban
development simulation results to serve as input for the hydrological modelling system ArcEGMO.
First modelling results show that the impact of urbanisation on the mean runoff is minor
compared to the impact of the assumed climatic changes. However, one catchment mainly affected
by the urbanisation process shows considerable changes in peak runoff figures compared to the
status quo landuse.
