| dc.description.abstract | Land subsidence represents a complex global occurrence influenced by a blend of natural processes and human activities, posing significant risks to both the environment and infrastructure. Despite the growing recognition of its importance, various challenges persist in effectively monitoring land subsidence. To enhance our comprehension of the mechanisms driving land subsidence, this research endeavors to introduce an innovative experimental model involving Distributed Fiber Optic Sensors (DFOS) employing Brillouin Optical Time Domain Reflectometry (BOTDR). This model aims to gauge the relative change in each sinking ring of the fiber, connected in a sequence of polyvinyl chloride (PVC) catheters at uniform intervals, in order to delve into the deformation characteristics of the stratum. The experiment offers a meter-scale spatial resolution within boreholes situated in Taiwan, allowing for a comprehensive examination of subsidence mechanisms. In addition to that, Laboratory as well as field experiments have carried out to investigate the efficiency of the proposed monitoring system for land subsidence evaluation. During laboratory experiments standard deviation of ≤ 0.23 mm was observed in the monitored displacement. Moreover, the Brillouin optical time domain analyzer (BOTDA) system recorded maximum subsidence of 13.68 mm on April 11, 2023, While the Brillouin optical time-domain reflectometry (BOTDR) has been recorded a subsidence of 13.65 mm on April, 17, 2024. Furthermore, results have compared with the magnetic ring as well as the ground water level thoroughly. The findings reveal the distribution of deformation across the entire borehole, shedding light on the primary contributors to subsidence and the evolution of deformation processes. Moreover, the consistent and long-term monitoring performance displayed by the DFOS approach underscores its potential to provide valuable insights into subsurface deformation. Consequently, this study suggests that DFOS technology can serve as a valuable tool in comprehending land subsidence processes, particularly in coastal and deltaic regions, offering an innovative and beneficial addition to established monitoring approaches. | en_US |