Japan Geoscience Union Meeting 2018

Presentation information

[JJ] Oral

A (Atmospheric and Hydrospheric Sciences) » A-HW Hydrology & Water Environment

[A-HW24] Hydrological change after the 2016 Kumamoto earthquake

Tue. May 22, 2018 1:45 PM - 3:15 PM A02 (Tokyo Bay Makuhari Hall)

convener:Jun Shimada(Graduate school of Science and Technology, Kumamoto University), Kei Nakagawa(Graduate School of Fisheries Science and Environmental Studies, Nagasaki University), Takahiro Hosono(熊本大学大学院先導機構, 共同), Takeshi Hayashi(Faculty of Education and Human Studies, Akita University), Chairperson:Hosono Takahiro(熊本大学先導機構), Nakagawa Kei(長崎大学大学院環境科学研究科)

2:45 PM - 3:00 PM

[AHW24-05] Evaluation of groundwater flow change by repeated measurements of subsurface temperature in the Kumamoto area: a comparison of subsurface temperature data from 2017 to 2018 and previous data

*Akinobu Miyakoshi1, Makoto Taniguchi2, Kiyoshi Ide3, Azusa Okumura3, Makoto Kagabu4, Takahiro Hosono5, Jun Shimada6 (1.Geological Survey of Japan, AIST, 2.Research Institute for Humanity and Nature, 3.Kumamoto University, 4.Faculty of Environmental Science, Nagasaki University, 5.Priority Organization for Innovation and Excellence, Kumamoto University, 6.Graduate school of Science and Technology, Kumamoto University)

Keywords:Subsurface temperature, repeated measurements of subsurface temperature, groundwater flow, urbanization, groundwater development, 2016 Kumamoto earthquake

Repeated measurements of subsurface temperature have been conducted from 2017 to 2018 to make an examination of groundwater flow changes in the Kumamoto area, Japan. We have also made a comparison of subsurface temperature data from 2017 to 2018 and previous data to evaluate not only effects of urbanization such as groundwater development, but the 2016 Kumamoto earthquakes to groundwater environment in this area. Dry up of natural springs and changes of groundwater level were observed aftermath the 2016 Kumamoto earthquakes, and it was expected that the earthquakes was affecting groundwater environment in this area.
Regional tendency was observed in the distribution of high and low temperatures. Low temperature area is located the upland which is the eastern part of this area. Relative High temperature area are found around the lowland which is the western part of this area. Similar tendency is recognized in the distribution of previous data, however there is a difference between high and low temperatures. Moreover, subsurface warming is widely recognized at the shallow part. The temperature increase is greater as close to surface, and it is considered to be affected by urbanization. On the other hand, a few points which shows temporary temperature changes were observed on the upland in January 2017. These unique points were not recognized in the winter of 2018, and the temporary temperature changes is considered to suggest the effects of groundwater flow changes due to the 2016 Kumamoto earthquake. We are expecting to be able to evaluate groundwater flow change by comparing our subsurface temperature data and other various groundwater data which are accumulated in the Kumamoto area.