Thermal UAS survey of reactivated hot spring activity in Waiwera, New Zealand

摘要

Abstract. The utilization of geothermal reservoirs as alternativeenergy source is becoming increasingly important worldwide. Throughclose-range aerial photogrammetry realized by unmanned aircraft systems(UAS), this study investigates the surface expression of a leaking warmwater reservoir in Waiwera, New Zealand, that has been known for manycenturies but remained little explored. Due to overproduction during the1960s and 1970s the reservoir has suffered significant pressure reduction,which resulted in the loss of artesian conditions and led to the desiccationof the hot springs in close succession. However, shortly after the recentshutdown of the primary user (Waiwera Thermal Resort Spa) renewedartesian activity was reported by locals but no hot spring activity has beenobserved so far. Therefore, this study was carried out in October 2019 toassess the actual conditions of thermal activity in the area of the formerhot springs. UAS with coupled thermal infrared cameras were used for thermalmapping and the obtained data show renewed activity of the hot springs onthe beachfront of Waiwera. Faults and fractures were identified as importantfluid pathways, as well as individual fluid conducting lithologies.