Japan Geoscience Union Meeting 2021

Presentation information

[J] Poster

O (Public ) » Public

[O-02] Natural disasters and people -Listen to the voice of the Earth on the Japanese Geoparks-

Sun. Jun 6, 2021 5:15 PM - 6:30 PM Ch.02

convener:Noritaka Matsubara(Graduate School of Regional Resource Management, University of Hyogo), Kyohei Sano(Graduate School of Regional Resource Management, University of Hyogo), Suzuka Koriyama(Itoigawa city), Hikaru Yokoyama(Hokusho University)

5:15 PM - 6:30 PM

[O02-P16] Lives of the local people on the collapsing land and the flowing land by river water -Think about geohazard program of Miyoshi geopark project-

*Azusa Tonotani1, Katsunori Ozakai1, Mizuki Tochitani1, Hiroyuki Ohnishi1, Toshiaki Matsumoto1 (1.Geopark Promotion office in Miyoshi city)

Keywords:Miyoshi geopark project, Geohazard, Land slide, Flood, MTL

Japan is known as one of the tectonic belt in the world. Therefore, various geohazards are caused such as the earthquake (subduction-zone and inland), volcanic eruption, the collapse of land (ex. land slide) and a heavy rain in Japan.

Miyoshi geopark project area is located in Tokushima prefecture and consists of all over the Miyoshi city area. As a feature of mainly geosciences are ;
1. Japanese median tectonic line (MTL) runs to east- west detection in this area. The south area of MTL is Shikoku Moutains and the north area is located Sanuki Mountain Range.
2. The south area mostly consists of Sambagawa metamorphic rock, and high mountains rise around 1500 m.
3. The average annual rainfall of Shikoku Mountains area in Miyoshi is about 2500 mm (heavy rain condition).
4. The Sanuki Mountain Range mainly consists of layers of sand stones and mud stones. Those layers often show the dip slope structure.
5. Yoshino river flows in Miyoshi area, sometimes cause floods at the middle and lower Yoshino-river area.

Those features triggered to cause the various geohazard such as the collapse of land (ex. land slide) and flood in past. Local people in this area lives together with distinctive geohazard for a long time, and we can see various those life style in local area even today. By way of example, Yokai stories (the oral tradition) in Miyoshi area are deeply associated with life style in a steeply and dangerous mountains area. Other example, local area name such as “Shima” area. Shima area is located in Ikeda town, and is often flooded because is located in the lowest river terrace.

Thus, a lot of original life style together with distinctive geohazard have been handed down in Miyoshi geopark project area. However, local area people don’t understand about each geohazard mechanism enough.

In this poster, we will introduce about the life style together with distinctive geohazard for a long time, and approach to various geohazards in Miyoshi geopark project area.