Browsing by Author "Huang, Mong-Han"

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A growing structure near the deformation front in SW Taiwan as deduced from SAR interferometry and geodetic observation
(2006-06-30)
Huang, Mong-Han
;
Hu, Jyr-Ching
;
Hsieh, Chia-Sheng
;
Ching, Kuo-En
;
Rau, Ruey-Juin
We apply the D-InSAR technique to monitor the active growing structure on the Tainan Tableland near the deformation front in SW Taiwan using ERS SAR images in the period of 1996 - 2000. Interferometric processing of six SAR images reveals the average slant range displacement (SRD) to be similar to 12.5 mm/yr, and it increases from the west edge of the Tainan Tableland and decreases across the Houchiali fault. The GPS campaign data indicate an average horizontal movement of 12 +/- 4 mm/yr in the direction of N44 degrees W for the Tainan Tableland with respect to the western coastline. Five precise leveling surveys across the Tainan Tableland over two years show an uplift rate of similar to 14 mm/yr for the benchmarks on the Tableland. By combining the horizontal velocity of GPS data and the SRD of D-InSAR we transfer the SRD into vertical deformation and discuss the deformation pattern and seismic hazards in the Tainan area.
Active deformation of Tainan tableland of southwestern Taiwan based on geodetic measurements and SAR interferometry
(2009-03-10)
Huang, Mong-Han
;
Hu, Jyr-Ching
;
Ching, Kuo-En
;
Rau, Ruey-Juin
;
Hsieh, Chia-Sheng
The D-InSAR technique is applied to detect the active fault-related folding structure of the Tainan tableland near the deformation front in SW Taiwan by using ERS SAR images during 1996-2000. The Tainan tableland is located in-between a blind fault in the west and the Houchiali fault in the east, thus the Tainan tableland is interpreted as a pop-up structure in a fold-thrust belt at active tectonic margin. Interferometric processing of six SAR images reveals the average slant range deformation (SRD) as similar to 12.5 mm/yr. The uplift rate is higher in eastern Tainan tableland than that in western Tainan tableland, and it increases from west edge of Tainan tableland and decreases across the Houchiali fault. The campaign-mode GPS data set from 1999 to 2003 indicate an average horizontal movement of 12 +/- 4 mm/yr in the direction of N44 degrees W for the Tainan tableland with respect to western coastline. Furthermore 5 precise leveling surveys across Tainan tableland over a period of 2 years show an uplift rate of similar to 14 mm/yr for the benchmarks on the tableland. Based on the 2-D analytical solution with the constraint of he inferred fault geometry, the slip rate along the inferred Tainan fault is similar to 16 mm/yr, similar to 10 mm/yr along the Houchiali fault, and similar to 25 mm/yr along the inferred Chungchou fault. Consequently we propose that active deformation of the Tainan tableland is likely resulted from the freely slipping of the Tainan fault and the Houchiali fault. The locking depth should be located on the deeper part of decollement, eastern of the Chungchou fault. In addition, the combination of D-InSAR, GPS data and the precise leveling data reveals that the short-term deformation rate is larger than long-term deformation rate, which implies that a destructive seismic event could occur in the eastern Tainan area. (c) 2007 Elsevier B.V. All rights reserved.
Using differential SAR interferometry to map land subsidence: a case study in the Pingtung Plain of SW Taiwan
(2011-09-01)
Hsieh, Chia-Sheng
;
Shih, Tian-Yuan
;
Hu, Jyr-Ching
;
Tung, Hsin
;
Huang, Mong-Han
Synthetic aperture radar (SAR) interferometry (InSAR) is a geodetic tool widely applied in the studies of earth-surface deformation. This technique has the benefits of high spatial resolution and centimetre-scale accuracy. Differential SAR interferometry (DInSAR) is used to measure ground deformation with repeat-pass SAR images. This study applied DInSAR and persistent scatterers InSAR (PSInSAR) for detecting land subsidence in the Pingtung Plain, southern Taiwan, between 1995 and 2000. In recent years, serious land subsidence occurred along coastal regions of Taiwan as a consequence of over-pumping of underground water. Results of this study revealed that the critical subsidence region is located on the coast near the estuary of Linpien River. It is also found that subsidence was significantly higher during the dry season than the wet season. The maximum annual subsidence rate of the dry season is up to -11.51 cm/year in critical subsidence region and the vertical land movement rate is much slower during the wet season. The average subsidence rates in wet and dry seasons are -0.31 and -3.37 cm/year, respectively. As a result, the subsidence rate in dry seasons is about 3 cm larger than in wet seasons.