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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXX V, Part B7. Istanbul 2004 
10 minutes. The numerically simulated run-up elevations 
showed that the maximum positive tsunami amplitudes near the 
shore can exceed the 3-m level on some parts of the coast, even 
reaching the 5-m level at some localities depending on the 
source and the coastal topography. Temporal histories, i.e. 
sequence and relative height of tsunami waves, showed similar 
appearances. 
The results should be considered as important risks for the 
shores of the Sea of Marmara where the coastline is densely 
populated and widely used for many purposes. 
3. MAPPING METHOD AND INLAND PENETRATION 
The inundation map was produced by numerically simulating 
the resulting tsunami waves due to scenario underwater failures, 
and mapping the maximum inland flooding limit. The first part 
was done by computer methods. The last step was 
accomplished chiefly by prior conclusions about inland 
penetration depending on the circumstantial characteristics of 
the inundation area and available topographic data (Priest, 
1995). 
Tsunami flooding or the volume of water carried onshore is 
directly related with the size of tsunami and its wave period. On 
the other hand, the cross-sectional area of coastline flooded by a 
tsunami is almost equal to that of water under the tsunami wave 
crest close to shore (Hills and Mader, 1997). The limit of 
landward incursion is the maximum distance that run-up can 
penetrate inland and can be given the following formula; 
Xn (Hs) n?k (1) 
where k is a constant and taken as 0.06 for many tsunamis. The 
term n is another constant and depends on the characteristics of 
the inundation area. It is 0.015 for smooth terrains such as 
grasslands or tidal plains, 0.03 for areas covered in buildings 
and 0.07 for landscapes densely covered with forest. 
Dry-land inundation distance across relatively flat ground was 
inferred by extrapolating the run-up elevation at the shoreline 
inland until a barrier was encountered or until a lateral distance 
was reached that conforms approximately to the above 
equation. A tsunami 2.6 m high can penetrate 950 m inland for 
smooth plains. However, since the study area is a developed 
land on flat coastal plains, such a tsunami can only penetrate 
250 m inland. 
3.1 Mapping Tsunami Inundation 
For definition of the inundation limit, a Digital Terrain Model 
(DTM) with a vertical resolution of + 1.2 m was used. On the 
basis of elevation data of the surface, a DTM creates 
topography by geometric surfaces in a computer environment. 
This method provides best approach to a 3D terrain surface 
using elevation points which were defined on a horizontal 
plane, from various data sources such as measured data, 
topographic maps, bathymetric data and images. Our DTM was 
produced from 1:25,000-scale topographic maps and has a cell 
size of 50 m. In order to define the environmental condition of 
the inundation area (smooth terrain, areas covered in buildings 
or forest), we have merged the DTM with respective IKONOS 
699 
  
with 1 m resolution. Finally, calculated inundation limits based 
on some assumptions were drawn on these maps (Figure 1-4). 
  
  
Figure 1. Inundation map drawn for the coastal area in front of 
Kücükcekmece lagoon. The line shows how far inland and 
uphill a tsunami caused by an underwater failure is expected to 
go. Taking into consideration the simulated tsunami waves due 
to scenario underwater failures, topographic elevations, 
settlement conditions and geographic characteristics of the 
inundation area, the maximum inland flooding limits were 
developed for the wave heights of 2 m at shore. 
  
  
Sea of Marmara 
Figure 2. Inundation map drawn for the coastal area of Yesilkoy 
airport, Ayamama creek and Atakóy Marina. Each line shows 
how far inland and uphill a tsunami caused by an underwater 
failure is expected to go. Taking into consideration the 
simulated tsunami waves, the maximum inland flooding limits 
were developed for the wave heights of 2, 2.5 and 3.0 m at 
shore, respectively.