Analysis Of Mudslide In Atami
Mudslides occur after soil and rock are washed down a slope after heavy rain. A debris flow can move as fast as a passenger car, making it difficult for people to evacuate once it occurs.
Mudslides occur in places with sharply inclined rivers or valleys, as well as in fan-shaped areas near a valley. They can also occur in places where volcanic ash has accumulated.
Mudslides can reoccur in the same place and caution is required.
Honorary professor at the Tokyo University of Agriculture and Technology, Ishikawa Yoshiharu, is an expert on landslides.
He said footage from Atami, Shizuoka Prefecture, shows a debris flow as it occurred.
He said the city is bordered by mountains with steep slopes and, in many cases, they are covered with a layer of volcanic soil, which can flow down a slope easily after absorbing water.
Ishikawa said a mudslide can reoccur if mud becomes even more waterlogged.
He said the risk of a mudslide does not diminish even after the rain subsides as it takes time for the ground to absorb water.
Ishikawa said the mudslide in Atami appears to have moved at a speed of dozens of kilometers per hour, and it would have been difficult to evacuate after it occurred.
He warns people to stay away from landslide caution zones while an evacuation order is in place.