Near the starting point of the debris flow, the prime of development acts almost collapsed or "I guess the damage has been enhanced"

Has completed

　静岡県は、土石流の起点となった場所をドローンで撮影し、４日に映像を公表した。起点は、熱海市内を流れる逢初（あいぞめ）川の河口から約２キロ上流にある。

　The prefecture presumed that there was about 50,000 cubic meters of about 50,000 cubic meters from the data after 2010.In this debris flow, it is expected that more than 50,000 meters collapsed.It is the amount of one hectares to increase the land of hectares by 5 meters, and the prefecture states that "it is unknown whether this collapse triggered the debris flow, but it has increased the damage."

　According to the prefecture and Atami City, companies in Kanagawa Prefecture reported to the city in 2007 based on the prefectural soil collection regulations.It has been reported around 11 years, and it is said that the soil caused by this construction has collapsed this time.

　Experts ask for the stability of the collapsed soil.According to Associate Professor Kinhin Hotta (Sabo Engineering) of the University of Tokyo, "Generally, the soil is more risky to collapse than the slope of nature.It may have been stable. "

　On the other hand, there is a possibility that the debris flow occurred multiple times, and Professor Tsuzo of Mie University (Sabo Engineering) said, "It collapses on the lower slope or eroded by heavy rain, causing an erosion in the lower slope.It cannot be denied that the soil has lost support and collapsed. "