Assessments of serious anthropogenic land subsidence in Yunlin County of central Taiwan from 1996 to 1999 by Persistent Scatterers InSAR

Anthropogenic ground subsidence due to massive pumping of groundwater is one of the severe environmental hazards in Taiwan. The Yunlin County located in the southwestern coastal region of Taiwan is one of the most counties with serious land subsidence because of the agricultural needs. In certain areas of the region, the subsidence rate reaches as much as 14.3 cm/yr. The severe land subsidence gives rise to the risk of flood hazard and damage of infrastructures in this area. We represented a Persistent Scatterers InSAR (PSInSAR) results deduced from 1996 to 1999 time span for monitoring of land subsidence in this area. The PSInSAR results show that Baojhou, Tuku and Yuanchang Townships reveal a maximum subsidence rate of about 7.8 cm/yr along the LOS and Lunbei Township located on the northern Yunlin reveals a subsidence rate of 3.5 cm/yr, which is quite coincident with the precise leveling result. This result has proven that the effective reduction of labor and cost could be achieved by using this technique on monitoring land subsidence in Yunlin County.

► We characterize ground subsidence of 7–8/cm in Yunlin County of central Taiwan.
► We figure out the potential damage of Taiwan High Speed Rail due to land subsidence.
► We use PSInSAR technique for the detection of shift in land subsidence from 1996 to 1999.