Differential SAR inteferometry for rapid earthquake detection and damage assessment | |
| Author | Nopphawan Tamkuan |
| Call Number | AIT Diss. no.RS-17-02 |
| Subject(s) | Earthquake damage --Assessment Interferometry |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Remote Sensing and Geographic Information Systems |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation;no. RS-17-02 |
| Abstract | Earthquake s are one of the most devastating natural disasters that happen with little to no warning around the world . It can cause major damages and fatalities in populated areas . Timely and accurate damage assessments can help to reduce adverse impacts on communities after earthquakes. Differential SAR interferometry ( DInSAR ) is the remote sensing technique , used in this study for measuring earthquake deformation rapid ly in all kind of weather s and large coverage . This technique was applied in two study areas for rapid damage detection mapping base d on interferometric coherences . Single polarization mode was analyz ed for Kumamoto earthquake occurred in 2016. Dual polarization mode was used for Nepal earthquake in 2015. On 14 April 2016, a foreshock occurred in the central Kyushu region of Japan . After only one day, main - shock hit Kumamoto again with 7 . 0 Mw (Moment magnitude ) . This study demonstrated that ALOS - 2 provided quick near real - time mapping to observe and evaluate damage area after few days of the event . The results showed the trend of fault line occurred by the interferogram of few fringes for foreshocks and more than ten fringes after the mainshock . Moreover, interferometric coherences between pre - and during the earthquake was examined to evaluate the d amage d area and compared to reconnaissance fieldwork . Normalized difference (ND) change index presented the hig h est accuracy for urban damage and landslide areas among all indices. Furthermore, this study combined Landsat - 8 and interferometric ALOS - 2 coher ence data without training area techniques by classifying the remote sensing ratios of specific features for damage assessment . The results presented three damage types; namely, damage to buildings caused by ground motion, liquefaction, and landslides. The overall accuracy ( 94 %) of the confusion matrix was excellent . Results for urban areas were divided into three damage levels ( e . g . , none – slight, slight – heavy, heavy – destructive ) at a high (90 % ) overall accuracy level . Moreover, data on buildings damaged by liquefaction and landslides were in good agreement with field survey information . DInSAR technique was used for detecting Nepal earthquake 7 . 8 Mw occurred on 25 April 2015 by ALOS - 2 images . DInSAR detected pre - and co - seismic line of sight ( LOS ) displacement by different polarization and time intervals . Pre - seismic LOS showed subsidence area in central part of Kathmandu with the maximum subsidence about 8 centimeters that subsidence was possible due to ground water consumption . Co - seismic LOS indi cated that surface displacement in the north of Kathmandu district was higher than the southern part . The maximum LOS was approximately 150 cm . DInSAR Polarizations of different time baseline were examined . The results indicated that short time baseline of HV (Horizontal transmission and vertical reception) images could process higher precision and coherence of interferogram pairs . The interferometric coherence of pre - seismic and co - seismic was used for potential mapping of urban damage. Average of HH (Hori zontal transmission and horizontal reception) and HV coherence changes obtained more accurate and precise for urban damage assessment than only single polarization. Classified l and cover s from dual polarization image presented with damage level by an average of HH and HV coherence change . The map result s showed good agreement with ground truth data by visual interpretation. DInSAR was a very effective technique for preliminary detection of Nepal and Ku mamoto earthquakes displacement. Moreover , the dam age assessment approaches of tw o study areas accurately assessed earthquake damage area s . This research provided rapid response to observ e the wide area and could be adaptable for supporting future disaster management . |
| Year | 2017 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation;no. RS-17-02 |
| Type | Dissertation |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Remote Sensing (RS) |
| Chairperson(s) | Nagai, Masahiko |
| Examination Committee(s) | Nakamura, Tai ;Miyazaki, Hiroyuki ;Pennung Warnitchai |
| Scholarship Donor(s) | Government of Japan |
| Degree | Thesis (Ph.D) - Asian Institute of Technology, 2017 |