The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vo I. XXXVII. Part B4. Beijing 2008 
the area of Btiyukcekmece covers residential areas on low- 
levelled terrain that finally can affect 30,000 people by a Tsu 
nami since they live in the red coloured zone as shown in Fig 
ure 6. Such risk maps easily can indicate city planners where 
risk-factors must be taken into account or at least to define clear 
rules for constructing objects in these risky regions. Maps as 
shown above also support the Crisis Management Team to de 
tect sensitive parts of the city and assist them in defining ways 
to access these areas for helping the people. 
Figure 6. Areas of a certain run-up risk for Tsunamis overlaid with land-use data and population density of residential areas. 
[Kemper 2006] 
Many scientists in our discipline use GIS in combination with 
remotely sensed data and/or aerial photos to extract the land-use 
and analyze them, commonly in combination with spatial or 
non-spatial ancillary data. Terrain-models are used for the 
orthorectification process but as shown above, they can do more. 
There are various possibilities to contribute to risk mapping out 
of such data-sources. Risk-maps also help the decision makers 
to understand the needs for a sustainable planning and support 
an integrated Crisis management. Crisis Management and the 
needed reorganisation of a city can find acceptance in the popu 
lation more easily by presenting these risk-maps than any other 
arguments can do. Like that, these maps have a big importance 
to transport political decisions which are needed for a success 
ful crisis management and so finally for a better help for the 
people. 6 
6. ENGINEERING AND ARCHITECTURE 
Concerning the quality of architecture, Istanbul has to deal with 
difficult “heritage”. This heritage is, the so-called Gececondu 
areas. These Gececondus are illegally built-up areas with small 
but also bigger residential buildings. Usually after some years, 
they were legalized by the city administration. Owners and their 
relatives, means that they were not built by engineering rules, 
built-up these houses. Depending on the political situation, es 
pecially during election terms, they were legalized later and 
then often enlarged with additional stories, a extremely critical 
activity. In most cases, these buildings are weak and not stabile 
against earthquake shocks. Some building even collapsed with 
out any earth shocks. Often also the foundation of buildings is 
weak especially if the building where increased. The scientific 
knowledge in constructing shock-proven buildings is well 
known in Turkey but has only rarely applied to the real work. 
To validate all buildings in Istanbul on their stability causes an 
enormous work. Nevertheless already, the over-planning of the 
former Gececondu areas takes place, which can be seen as a 
good chance for planning new residential areas that consider the 
risk and make live more safety. Actually, there is a big need to 
get data of the buildings about their static-stability, their use and 
their internal infrastructure e.g. if there are heavy machines, 
lifts, gas-pipelines... It is also worth to know how many people 
in which daytime stay inside the building. Are Emergency ex 
ists available and do they really guide to a safer place? To col 
lect these data, field mapping is very limited since it accesses 
only the outside part of the building. Oblique imaging tech 
nologies e.g. pictometry, can assist in same way as they do for 
home security analysis in other parts of the world. Such images 
can help engineers and other specialists to validate the static of 
a building since they enable the view to typical constructive 
elements of the building.