Abstract
Mamuju, West Sulawesi, is an area in Indonesia with high radiation levels. A high radiation dose rate was detected in Adang volcanic rock. Activities related to radioactive minerals contained in rocks and soil may release hazardous radiation into the environment. The study area generally exhibits a highly irregular morphology that provides limited access because of the high slope gradient of the volcanic terrain. Therefore, it is challenging to identify and map minerals carrying radioactive elements via Sentinel-2 remote sensing. Since optical satellite images are superior in land cover detection, we proposed a mapping technique for radioactive carrier minerals based on vegetation indices verified by chlorophyll field measurements. We applied band rationing to identify the distribution of hydrothermal alteration minerals and vegetation stress, while field chlorophyll measurements of Dryopteris marginalis and Nephrolepis exaltata were conducted. The Sentinel-2 color composite of images with 4/2, 8A/11, and 11/12 RGB band ratios revealed the distribution of iron oxide, ferromagnesian silicates, and clay minerals. High levels of uranium (U) were scattered in leucite basalt rocks, with a broad distribution of iron oxide minerals and small amounts of ferromagnesian minerals. In contrast, the presence of thorium was not affected by the presence of these minerals. In addition, band rationing of chlorophyll spectra captured by the red edge vegetation index (REVI) was used as the basis for vegetation stress mapping related to radiation exposure based on the chlorophyll content in ferns in the study area. The REVI image showed an anomalous vegetation stress concordant with the high radioactivity. To obtain more accurate results, ground measurements were also performed to identify the vegetation stress due to the presence of minerals carrying radioactive elements. The areas with radioactive mineralization and vegetation stress were located upstream of the Mamuju River and the Botteng and Ahu areas in Tapalang.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
