Status : Verified
| Personal Name | Bauzon, Ma. Divina Angela I. |
|---|---|
| Resource Title | Shoreline change and ground deformation analysis of post-2013 earthquake in Bohol, Philippines |
| Date Issued | 02 July 2021 |
| Abstract | After the 2013 Mw 7.2 earthquake that occurred in Bohol, the shoreline specifically in Loon and Maribojoc was observed to shift seaward due to ground uplift. This study analyzes the shoreline change along 12 km of coastal strip from Loon to Maribojoc using threshold-based method. Sentinel-1 Ground Range Detected (GRD) images each year from October 2014 to April 2018 were processed to extract shorelines using land cover classification technique. The linear regression shoreline rate from DSAS (Digital Shoreline Analysis System) was computed to be -4.36 m/yr in Loon and -1.69 m/yr in Maribojoc. The negative sign indicates a landward shift of shoreline with 91.4% and 88.8% of shoreline transects in Loon and Maribojoc, respectively. Results showed that there is a revert of shoreline suggesting a possible elastic rebound after the earthquake. Ground deformation rates were estimated using the Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) technique. Sentinel-1 Single Look Complex (SLC) images from October 2014 to December 2018 were processed for line-of-sight (LOS) velocity. The LOS velocity was converted to vertical velocity to determine the rate of vertical land motion (VLM). Results showed varying rates in the study area with Loon and Maribojoc exhibiting a subsidence rate of -2 to -8 mm/yr. The correlation between the shoreline retreat and the land subsidence is 87%. This suggests that the landward shoreline movement is due to ground subsidence. Tagbilaran City was also analyzed to determine if the tide gauge installed in the said area was affected by ground movement. The portion of Tagbilaran City on its northern side exhibits land subsidence of -2 to -6 mm/yr while its southern side exhibits land uplift of 0 to 2 mm/yr. The relative sea level fall from tide gauge sea level (TGSL) measurements is indicative of an uplift in the location of the tide gauge. |
| Degree Course | MS Geomatics Engineering |
| Language | English |
| Keyword | shoreline changes; ground deformation; Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR); Digital Shoreline Analysis System (DSAS); elastic rebound |
| Material Type | Thesis/Dissertation |
Preliminary Pages
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Category : P - Author wishes to publish the work personally.
Access Permission : Limited Access