Technical Report

A proposal to increase the precision of “information on the hazard periods”, a component of Emergency Information on Sediment-related Disasters -Evaluation of risk of occurrence of debris flow induced by the deposition of volcanic ash-fall-

Masaru KUNITOMO, Shinjiro TSURUMOTO, Kazuhiro SHIMOKUBO, Shuichi ASO, Shigemitsu SUGIHARA, Yoshinori ARAKI, Kazumasa KURAMOTO, Osamu UENO and Kohei FURUKAWA　　3

The feature of surface runoff caused by rainfall on hillslopes covered with the tephra by the 2011 Eruption of Shinmoe-dake, Kirishima Volcano

Hiroshi KISA, Takao YAMAKOSHI, Tadanori ISHIZUKA, Mitsunori SUGIYAMA and Shigetaka TAKIGUCHI　　12

Assessing of scale and susceptibility of landslides to earthquake focused on slope relief

Nagazumi TAKEZAWA, Taro UCHIDA, Tadanori ISHIZUKA, Shinichi HONMA, Yoko KOBAYASHI and Masakatsu MIYAJIMA　　22

Vegetation and soil properties of Sakurajima volcanic ash and their effect on the in situ infiltration rate of surface soil

Atsuhiko KINOSHITA, Yusuke SAKAI, Ryoichi OHNO, Akio SATO and Fumitoshi NISHIKUBO　　30

Characteristics of juvenile pyroclastic materials affected on runoff and sediment discharge. −A Case Study of the 2011 Eruption of the Shinmoedake−

Takashi KOI, Yasuhiro FUJISAWA, Koji FUJITA, Nobuo ANYOJI, Shigetaka TAKIGUCHI and Mitsunori SUGIYAMA　　37

Research Notes

Field observations of unit weight of flowing debris flows by force plate in Sakurajima, Japan

Tsuyoshi OSAKA, Eiichi TAKAHASHI, Masaru KUNITOMO, Takao YAMAKOSHI, Yukinori NOWA, Hiroshi KISA, Tadanori ISHIZUKA, Rei UTSUNOMIYA, Koji YOKOYAMA and Takahisa MIZUYAMA　　46