Earthquake damage detection using watershed segmentation and intensity-gradient orientation approaches

Download
index.pdf
2004
Sümer, Emre
Show full item record
190
views
84
downloads
Earthquake is one of the most destructive natural disasters on earth. Rapid and reliable post-quake damage assessment has an important role to reduce the drastic effects of an earthquake by setting the responsible agencies in motion. In this study, the collapsed buildings due to earthquake were detected from post-event aerial images. Two approaches were proposed to detect the collapsed buildings. These approaches were implemented in a selected urban area of Golcuk. The first approach was based on the analysis of shadow casting edges. First, the shadow casting edges of the buildings were identified and a buffer zone was generated for each building polygon along these edges. Then, the shadow regions were detected using the watershed segmentation algorithm. This was followed by measuring the agreement between the shadow producing edges of the buildings and their corresponding shadows. Of the 284 buildings analyzed, 229 were successfully labeled as collapsed or un-collapsed providing an overall accuracy of 80,63%.In the second approach, a two-branch method based on building light intensities and the gradient orientation was used. In the first branch, an intensity threshold was determined and applied to building image patches. Then, a pixel ratio was computed to categorize the buildings. In the second branch, a series of processings were carried out including the smoothing of the building image patches and the determination of the magnitude and the orientation of the gradient. Then, an optimum angle threshold was determined to label the buildings. The final decision about the condition of a building was made by integrating the two branches. Of the 284 buildings analyzed, 254 were correctly labeled providing an overall accuracy of 89,44%. The same assessments were repeated after generating a one-pixel wide buffer zone around the building polygons and an overall accuracy of
Computer software.
http://etd.lib.metu.edu.tr/upload/12605485/index.pdf
https://hdl.handle.net/11511/14436
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

Estimation of dynamic soil properties and soil amplification ratios with alternative techniques
Şişman, Fatma Nurten; Askan Gündoğan, Ayşegül; Özacar, Atilla Arda; Department of Earthquake Studies (2013)
Earthquakes are among the most destructive natural disasters affecting urban populations. Structural damage caused by the earthquakes varies depending not only on the seismic source and propagation properties but also on the soil properties. The amplitude and frequency content of seismic shear waves reaching the earth’s surface is dependent on local soil conditions. It is well known that the soft sediments on top of hard bedrock can greatly amplify the ground motion and cause severe structural damage. When ...
Seismic retrofitting of reinforced concrete buildings using steel braces with shear link
Durucan, Cengizhan; Dicleli, Murat; Department of Engineering Sciences (2009)
The catastrophic damage to the infrastructure due to the most recent major earthquakes around the world demonstrated the seismic vulnerability of many existing reinforced concrete buildings. Accordingly, this thesis is focused on a proposed seismic retrofitting system (PSRS) configured to upgrade the performance of seismically vulnerable reinforced concrete buildings. The proposed system is composed of a rigid steel frame with chevron braces and a conventional energy dissipating shear link. The retrofitting...
Relationships between felt intensity and instrumental ground motion parameters for Turkey
Bilal, Mustafa; Askan Gündoğan, Ayşegül; Department of Civil Engineering (2013)
Earthquakes are among natural disasters with significant damage potential; however it is possible to reduce the losses by taking several remedies. Reduction of seismic losses starts with identifying and estimating the expected damage to some accuracy. Since both the design styles and the construction defects exhibit mostly local properties all over the world, damage estimations should be performed at regional levels. Another important issue in disaster mitigation is to determine a robust measure of ground m...
Seismic response of hunchbacked block type gravity quay walls
Yuksel, Z. Tugce; YÜKSEL, Yalçın; Çetin, Kemal Önder; ÇEVİK, Esin (2017-10-01)
Earthquakes near major cities may cause big social and economic impacts. Damages to port facilities may cripple the economy. The past twenty years' experience has proven the high vulnerability of the port facilities. This fact, along with the economic importance of port structures, indicates the need for better seismic design approaches for berth structures and cargo handling facilities. In the recent decades, there have been many incidences of failure of gravity type quay walls. These failures have stimula...
Satellite Remote Sensing and Hydrologic Modeling for Flood Inundation Mapping in Lake Victoria Basin: Implications for Hydrologic Prediction in Ungauged Basins
Khan, Sadiq I.; Hong, Yang; Wang, Jiahu; Yılmaz, Koray Kamil; Gourley, Jonathan J.; Adler, Robert F.; Brakenridge, G. Robert; Policelli, Fritz; Habib, Shahid; Irwin, Daniel (2011-01-01)
Floods are among the most catastrophic natural disasters around the globe impacting human lives and infrastructure. Implementation of a flood prediction system can potentially help mitigate flood-induced hazards. Such a system typically requires implementation and calibration of a hydrologic model using in situ observations (i.e., rain and stream gauges). Recently, satellite remote sensing data have emerged as a viable alternative or supplement to in situ observations due to their availability over vast ung...
Citation Formats
E. Sümer, “Earthquake damage detection using watershed segmentation and intensity-gradient orientation approaches,” M.S. - Master of Science, Middle East Technical University, 2004.
METU IIS - Integrated Information Service open@metu.edu.tr