Remote sensing-based deformation monitoring of pagodas at the Bagan cultural heritage site, Myanmar

As a World Cultural Heritage site with sacred landscape featuring an exceptional range of Buddhist art and architecture, much attention has been focused on the sustainable development of Bagan (Myanmar). Particularly, the monitoring of landscape surface subsidence and monument instability is of great importance to the protection and development planning of the Bagan heritage site. In this study, we applied high resolution TerraSAR-X imagery acquired from 2019 to 2020 for deformation monitoring based on the small baseline subset (SBAS) and persistent scatterer synthetic aperture radar interferometry (PSInSAR) approaches. We identified several hotspots and pagodas with displacement anomalies linked to land cover change and previous earthquakes. The cross comparison between SBAS and PSInSAR and the precision of height estimates derived by PSInSAR indicated a millimetric precision of the derived deformation products. The combination of the two multi-temporal SAR interferometry approaches satisfies the two-scale monitoring requirements from landscapes to monuments, particularly for large-scale World Heritage sites. The non-contact monitoring method has potential when traditional methods using field accessibility and surveillance are constrained.

Automated summary

In this study, deformation monitoring of the Bagan heritage site in Myanmar was conducted using high resolution TerraSAR-X imagery and multi-temporal SAR interferometry. The results revealed displacement anomalies in pagodas linked to land cover change and previous earthquakes. The method showed millimetric precision and is suitable for monitoring large-scale World Heritage sites.