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

AbstractIt is considered that the extent of damage due to the sediment]related disaster induced landslides were influenced the scale of landslide. Meanwhile, the Scale of landslide was controlled by scale of slope. So, we investigated relationship between slope relief and scale of landslide using 3871 landslides data due to the Iwate and Miyagi inland earthquake in 2008. And we were identified 3871 landslides by two types of sediment movement. At result, landslide susceptibility was confirmed by using slope relief. Also, in the landslide area ranges from 100]1,000m2 to 5,000]50,000m2, the window size indicating the highest landslide mesh ratio is 3×3 in most cases. In the range of 10,000]100,000m2 on both types of sediment movement, however, the window size of 5×5 when the cover ratio is about 0.5 to 0.7 indicates the highest landslide mesh ratio. The assessing of landslide susceptibility to earthquake using slope relief is not influenced by types of sediment movement.