The Iwate-Miyagi Nairiku Earthquake in 2008 brought heavy damage around the border of Iwate and Miyagi prefecture. A lot of landslide dams were caused by collapsed soil mass. Geographic features of the dams were surveyed. One of the landslide dams in Numakuraura-sawa caused surge flow to downstream. This was triggered by over flow and erosion of the dam and observed as the sudden increase of inflow to the Kurikoma dam reservoir in the downstream. Typhoon Talas landed at the Shikoku Island, Japan in early September, 2011 and it brought serious damage in the Kii Peninsula. Disaster caused by the typhoon was characterized that many deep catastrophic landslides occurred and it enlarged damage. In addition, deep catastrophic landslide formed several landslide dams. It was tried to simulate a debris flow prone area caused by outburst of a dam and to predict the time of overflow occurrence for mitigation to disaster due to landslide dams. |