DINSAR APPLICATION FOR DETECTING THE SOIL LIQUEFACTION CAUSED BY MEINONG EARTHQUAKE IN TAINAN CITY, TAIWAN

On 6 February 2016, the Mw=6.4 Meinong earthquake occurred in Kaohsiung, southern Taiwan. This earthquake ruined a lot of buildings and caused the deaths of 117 people in Tainan City. Besides, many residents face the soil liquefaction problem and the house structure damage. In this study we use the Sentinel-1A SAR images from ESA to analyze the distribution of soil liquefaction in Tainan City after Meinong earthquake. Two image pairs 20160202-20160214 (ascending orbit) and 20160204-20160216 (descending orbit) are processed with DInSAR technique. According the geometry between the surface and satellite (look angle and flight direction) we assume the N-S directional movement does not offer into the LOS (line-of-sight) displacement, and calculate the E-W directional movement and vertical movement. The preliminary result shows the inversion displacement is similar with GPS results, and the middle/high potential area of soil liquefaction matches the subsidence area. Furthermore some subsidence area not including in the middle/high potential area is related to old ponds or farms. In the future we will collect the drilling core, groundwater level and PGA to model the vertical displacement of soil liquefaction.