5:15 PM - 6:30 PM
[STT34-P01] Geological structure survey by drone airborne electromagnetic survey method
Keywords:drone, Airborne electromagnetic survey, Drone airborne electromagnetic survey, D-GREATEM, D-TEM
The drone airborne electromagnetic survey method (D-GREATEM) has been in practical use for several years, and has been used for tunnel route surveys and landslide surveys. We have developed a new transmission device that can be mounted on a drone, and obtained the resistivity structure by using a method called D-TEM, in which two drones towing a transmission device and a reception device are flown simultaneously to measure the resistivity structure. The survey was carried out in the Seino region to understand the structure and hydraulic properties of fan-shaped sand and gravel, which are the recharge sources of groundwater in the Nobi Plain, alluvial clay that causes groundwater to be pressurized, and faults that can regulate groundwater flow. In order to capture seasonal changes in groundwater, the study was conducted twice, during the high rainfall season (September-October 2019) and the low rainfall season (December 2019), and these results were reported at the Japan Geoscience Union 2020 Conference (Yuki et al., 2020).
In this paper, we report on the results of the D-GREATEM and D-TEM expeditions conducted in 2020, following last year's report. Two surveys were carried out in September and December 2020 on the same survey line. The results of D-GREATEM were compared with the results of the previous exploration to confirm the reproducibility of the exploration technique and to examine the geological and hydraulic structures by differentiating the two periods. The D-TEM was conducted on the same survey line as the D-GREATEM, and the depth and resolution of the D-TEM were verified by comparing the results.
The survey area was a non-dense populated area with a lot of farmland, but it was also dotted with private houses and factories, and the roads were lined with power distribution lines. In some areas, underground lines for high-voltage power transmission were buried, and the influence of these measurement environments on the exploration results was also examined.
This paper reports the results of the comparison of the results of the two surveys, D-GREATEM and D-TEM, and discusses the characteristics and limitations of each method, estimation of geological and hydraulic structures, and the effects of measurement conditions.
This survey was conducted by the Strategic Innovation Program (SIP) "Strengthening National Resilience (Disaster Prevention and Mitigation)" of the Council for Science, Technology and Innovation (CSTI), Cabinet Office, Government of Japan (administrator: Disaster Prevention Research Institute).
In this paper, we report on the results of the D-GREATEM and D-TEM expeditions conducted in 2020, following last year's report. Two surveys were carried out in September and December 2020 on the same survey line. The results of D-GREATEM were compared with the results of the previous exploration to confirm the reproducibility of the exploration technique and to examine the geological and hydraulic structures by differentiating the two periods. The D-TEM was conducted on the same survey line as the D-GREATEM, and the depth and resolution of the D-TEM were verified by comparing the results.
The survey area was a non-dense populated area with a lot of farmland, but it was also dotted with private houses and factories, and the roads were lined with power distribution lines. In some areas, underground lines for high-voltage power transmission were buried, and the influence of these measurement environments on the exploration results was also examined.
This paper reports the results of the comparison of the results of the two surveys, D-GREATEM and D-TEM, and discusses the characteristics and limitations of each method, estimation of geological and hydraulic structures, and the effects of measurement conditions.
This survey was conducted by the Strategic Innovation Program (SIP) "Strengthening National Resilience (Disaster Prevention and Mitigation)" of the Council for Science, Technology and Innovation (CSTI), Cabinet Office, Government of Japan (administrator: Disaster Prevention Research Institute).