International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B4, 2012
XXII ISPRS Congress, 25 August - 01 September 2012, Melbourne, Australia
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UNDERSTANDING THE PAST, MANAGING THE FUTURE
Remotely sensed analysis of the urban sprawl of Istanbul for supporting decision making for a sustainable future
Orhan Altan Gerhard Kemper 2
1: Istanbul Technical University / Turkey
2: GGS - Geotechnik, Geoinformatik & Service GmbH, Speyer / Germany
KEY WORDS: Human Settlement, Change Detection, Understanding, GIS, Multitemporal, Geography
ABSTRACT:
The GIS based analysis of the land use change of Istanbul delivers a huge and comprehensive database that can be used for further
analysis. Trend analysis and scenarios enable a view to the future that highlights the needs for a proper planning. Also the
understanding via comparison to other cities assists in order not to copy errors from other cities. GIS in combination with ancillary
data open a wide field for managing the future of Istanbul.
l. BACKGROUND
A number of megacities have been analysed to quantify their
growth in various international research projects. One of them
was the “Moland” (Monitoring Landuse Dynamic) Project. Its
aim was to compare more than 30 urban areas of Europe to
understand common and specific key-actions that influence the
how’s and why’s of the urban growth. The use of a standardized
legend with more than 60 classes and the selection of a similar
times window enabled a direct correlation of the results. Also
the city of Istanbul has been selected for a project to detect and
understand the growth of the city within the last 60 years. The
years 1945, 1968, 1988 and 2000 were selected and aerial
photographs, satellite photographs and satellite data evaluated
in combination with ancillary data as maps, statistics and many
more.
To achieve these results, image georeferencing, orthorcctifi-
cation, pansharping and many other tools of photogrammetry
where used to get a geometric reliable data basis. Accuracy
investigations are part of the quality management. The final
extraction of homogenise land use pattern was done by manual
digitizing and interpretation. However, also automatic
classification methods have been tested and compared with the
manual interpretation. A difficult task was the combination of
spatial land-use data with ancillary data sources e.g. census
information. Some interesting additional results were generated
from this step.
The results show both, the sprawl in common and the class
specific changes within the city. In combination with census
data and other data, a complex special and semi special
understanding of the reasons for Istanbul’s sprawl was
performed.
As a first result, Istanbul is compared with other cities within
the Moland Project. This shows how different European cities
developed within this period. Then also a wider analysis was
done to compare Istanbul in a worldwide context. Not just the
validation of the analysed data, also scenarios derived from
trend analysis are made in order to compare Istanbul in a world
wide context of mega cities.
Te results, however, must become part of decision making and
planning and management of Istanbul’s future. For what can
these information and data be used?
First of all, as followed on the derived spatial database in GIS
environment, city planning with the establishment of
sustainable master plans is the logic next step. The trend
analysis and the estimation of sprawl axis assist to prevent
Istanbul against an uncontrolled grow.
But also infrastructural development especially transport
facilities is extremely important. Still, the construction of a
public transport is far behind the actual needs. The trend of the
urban sprawl gives information where and when infrastructural
facilities are needed.
As a social aspect, the development inside the city is important
to prevent Istanbul against social conflicts like ghettos, high
contrast of poor and rich areas and slope of the social balance.
We already can detect social misbalance in the urban structure.
Istanbul is placed on a tectonically risky zone, earthquakes and
tsunamis can hit the city and therefore a Disaster Management
System is to be established. The actual urban structure, the
information of the infrastructure, social aspects must become
part of a crisis preparedness plan, a well trained disaster alert
system and the final disaster management.
To have a good urban climate in Mega cities is a problematic
task today. As a part of a sustainable development, most
industrial plants have been moved to the suburb areas, however,
they are again surrounded today by residential areas with high
buildings that hamper the exchange of fresh air. The
development trend, the urban structure in combination with
meteorological models can assist to better the situation in
future.
Cultural heritage is an important factor of Istanbul’s tourist
business. The urban sprawl influences the environment of
cultural heritage sites and can increase the risk of such objects.
Changes of the silhouette already shows negative very clearly
but also infrastructural facilities and air pollution create a
negative influence on such objects. The risk that buildings
create to damage on cultural objects due to bad construction in
combination with earthquakes is another important factor.
There are several more applications that can be presented to
show, how GIS analysis on urban dynamics assist to understand
the mechanism of urban sprawl and their influence on various
activities of the cities development.
2. LANDUSE DYNAMIC OF ISTANBUL
The project MOLAND for Istanbul has been a co-operation
between the technical university of Istanbul (ITU), the company
GGS in Germany and funded by the European commission
through the JRC in Ispra / I. The first goal was the detection of
