Japan Geoscience Union Meeting 2021

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[J] Oral

M (Multidisciplinary and Interdisciplinary) » M-GI General Geosciences, Information Geosciences & Simulations

[M-GI34] Earth and planetary informatics with huge data management

Thu. Jun 3, 2021 10:45 AM - 12:15 PM Ch.03 (Zoom Room 03)

convener:Ken T. Murata(National Institute of Information and Communications Technology), Susumu Nonogaki(Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology), Rie Honda(Department of Science and Technology, System of Natual Science, Kochi University), Keiichiro Fukazawa(Academic Center for Computing and Media Studies, Kyoto University), Chairperson:Susumu Nonogaki(Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology), Rie Honda(Department of Science and Technology, System of Natual Science, Kochi University)

11:50 AM - 12:05 PM

[MGI34-11] Detection of geothermal fluids paths in highly vegetated area through a vegetation stress index using hyperspectral satellite imagery

*Taiki Kubo1, Hiroaki Gonnokami1, Mohamad Nur Heriawan2, Katsuaki Koike1 (1.Graduate School of Engineering, Kyoto University, 2.Institut Teknologi Bandung)

Keywords:geothermal resource exploration, Hyperion, Indonesia, remote sensing, spectral unmixing

Detection of geothermal fluids paths including steam and gas from a geothermal reservoir is a major target of geothermal prospecting. Remote sensing analysis is one of the low-cost and effective methods to detect fractures distribution that have a function as fluid flow paths. However, vegetation cover is an obstacle for prospecting when the geothermal potential field are located in tropical mountainous areas. In this study, we extracted geothermal manifestations from highly vegetated areas using the linear spectral unmixing (LSU) method and a vegetation stress index. Hede et al. (2015) applied a vegetation stress index calculated from multispectral data, and we improved the index, termed as Vegetation Index considering Blue shift and Shortwave infrared (VIBS), using hyperspectral data which has a higher wavelength resolution. The Wayang Windu Geothermal Field (WWGF) situated in West Java, Indonesia was selected as a study site. Vegetation-covered zones were extracted from a hyperspectral image, obtained by Hyperion using the application of LSU. The spatial distribution of VIBS was clarified over the whole vegetation-covered area. The high-stress zones by VIBS were mainly overlapped with the location of geothermal manifestations in WWGF. In addition, lineament distribution was estimated from DEMNAS, the digital elevation model provided by the geospatial information agency of Indonesia. The high permeable zones were estimated from the lineament distribution and the result of the radon gas survey (Heriawan et al., 2020). The corresponding high-stress with the estimated high permeable zones suggested the presence of permeable fractures that act as the ascent paths of geothermal fluid flows.