International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B7. Istanbul 2004 
  
3. CONCLUSION 
The 17 August 1999 earthquake has revealed that reliable and 
rapid information about the effects and affected areas is one of 
the vital issues. Photogrammetry and remote sensing methods 
and means provide rapid and reliable information sources. On 
the other hand, scientific activities on earthquake research can 
be classified based on geodesy-geology, photogrammetry- 
remote sensing and geographic information systems. Of these, 
geodesy and geology deals with plate motion and soil 
mechanics. And GIS based methods provide information for 
rescue, determination of damaged structures and rebuilding. 
Photogrammetry and remote sensing based methods, in that 
aerial photographs, satellite images and SAR laser profiling data 
are used, provide wide opportunities for determination of 
ground displacement depending on resolution and measuring 
accuracy. Aerial photographs can be used especially both in 
detailed analysis studies of the limited comprehensive 
earthquake affected areas and as a reliable data source for the 
reconstruction applications by means of orthophoto maps 
produced in the wide comprehensive affected areas. 
The main components, which affect reliability and accuracy, 
are; 
- The images have to be taken in a limited time range and in the 
same part of the year, 
- Aerial photographs pertaining to pre- and post-situation of 
earthquake have to be in large scales (such as 1:5.000, 
1:10.000). 
Based on the aerial photogrammetric evaluations conducted 
along the southern coast of the Sapanca Lake, displacement 
vectors determined show a liquefaction movement and confirm 
the site observations, which were done at liquefaction areas. It is 
also noted that towards the south part of Sapanca town, where 
liquefaction has not been observed, some displacement vectors 
were also determined. These vectors indicate some 
displacement contributing to the main deformations due to 
liquefaction induced lateral spreading along the coast of the 
lake. On the contrary to these, displacement vectors at the 
northern part of Sapanca Lake - Esme, at the northern part of 
left corner of Sapanca Lake are parallel to the fault, which 
caused the earthquake. At this part of the site no liquefaction 
has occurred, and therefore, it can be concluded that the 
permanent ground deformation is highly associated with the 
movement of the fault. 
Photogrammetric evaluations conducted along the southern 
coast of the izmit Bay and in the Sakarya city center, 
displacement vectors determined show a movement of 
liquefaction and faulting together. But the dominant factor in 
this movement is faulting. 
And a different technique was applied in the measurements 
done in Avcilar area. In these measurements different scaled 
and dated aerial photographs were used. The displacements 
indicate not a standard movement and show different 
characteristics between the years. 
This part of the study is considered to be valuable for further 
geotechnical assessments which will be carried out at the next 
phases by the geo-technical group. 
REFERENCES 
Aksu, O., Bardet, J.P., Atak, V.O., Ónder, M., Aydan, O., 16-18 
December 2002, Measurement of Ground Deformation Induced 
by Liquefaction and Faulting in the Earthquake Area of the 
1999 Kocaeli Earthquake, The Eight U.S.-Japan Workshop on 
Earthquake Resistant Design of Lifeline Facilities and 
Countermeasures against Liquefaction, Tokyo, Japan. 
Atak, V. O., Aksu, O., Onder, M., Aydan, O., Toz, G., 8-10 
October 2003, Zeminlerde Sivilagsmaya ve Faylanmaya Bagh 
Yer Degistirmelerin Yón ve Büyüklüklerinin Fotogrametrik 
Yontemlerle Belirlenmesi, Kügükgekmece ve Yakin Gevresi 
Teknik Kongresi ‘Deprem ve Planlama’, istanbul, Türkiye. 
Aydan, Ó., and Hamada, M., 1992, The site investigation of 
Erzincan (Turkey) Earthquake of March 13, 1992. 4th Japan-US 
Workshop on Earthquake Resistant Design of Lifeline Facilities 
and Countermeasures Against Soil Liquefaction, Honolulu, pp, 
17-34. 
Aydan, Ó., Ulusay, R., Hasgür, Z. and Taskin, B., 1999, A Site 
Investigation of Kocaeli Earthquake of August 17, 1999, 
Turkish Earthquake Foundation, 180 p. 
Hamada, M., 1992, Large Ground Deformations and Their 
Effects on Lifelines: 1964 Niigata Earthquake. "Case Studies of 
Liquefaction and Lifeline Performance During Past 
Earthquakes", Vol.1: Japanese Case Studies. Tech.Rep. NCEER 
—92-0001, M.Hamada and T.D.O'Rourke (eds.), National Center 
for Earthquake Eng. Research, Bufallo, N.Y. 
Youd, T. L., 1992, Liquefaction, Ground Failure, and Con- 
sequent Damage During the 22 April 1991 Costa Rica 
Earthquake, Effects on Soils and Structures, Oakland, 
California, Earthquake Engineering Research Institute. 
ACKNOWLEDGMENT 
The authors thank to Prof. Dr. Resat ULUSAY and laboured 
personnel of Department of Photogrammetry in General 
Command of Mapping for their significant contributions to this 
project. 
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