Assessment on geoarchaeological sensitivity value of the almost forgotten ancient river relocation in Prambanan Temple Complex, Indonesia

Prambanan Temple is one of Indonesia's UNESCO World Heritage Sites. Its construction in the 9th century AD required a series of geoecological prerequisites. To meet these requirements and protect the temple complex from erosion, the course of the Opak River was relocated and the third temple’s courtayard fence was repositioned by ancient javanese people in the context of anthropogenic relocation of landform. However, the relocation of Opak River course has received relatively little attention in discussions about the anthropogenic landform relocation on Prambanan Temple construction. Consequently, the relocated river course faces risks of damage and is increasingly disconnected from its archaeological context. This research aims to (1) conduct a geoarchaeological significance assessment; (2) conduct a threat assessment based on the probability and impact of possible disasters; (3) conduct a vulnerability assessment on the Prambanan-Opak river relocation geoarchaeological heritage attributes; (4) assess the geoarchaeological sensitivity index based on geoarchaeological significance, threats, and vulnerability in the Prambanan-Opak river relocation geoarchaeological heritage attribute. The findings reveal that the relocated segment of the Opak River that flows through Prambanan Temple can be considered a geoarchaeological attribute of Prambanan Temple and has high significance values, yet it faces low threats and medium vulnerability. The geoarchaeological sensitivity index shows a low value. However, attention to its existence needs to be considered given its intrinsic and extrinsic values, even though the geoarchaeological sensitivity index shows a low value.