LANDSLIDES AND PRECIPITATION CHARACTERISTICS DURING THE TYPHOON LIONROCK IN IWATE PREFECTURE, JAPAN
Keywords:Typhoon, Tropical Cyclone, Landslides, Rainfall, Intensity–duration threshold, Critical rainfall
In August 2016, the typhoon Lionrock made landfall on Japan's northeastern coast and caused
floods and landslides. Lionrock b rought heavy precipitation to Japan, which Shimotokusari station (33201)
recorded 24-hour rainfall amount over 200 mm and the peak rainfall intensity was approximately 65 mm/hr.
The total cost of damage within the Iwate pre fecture is over 700 million dolla rs, moreover, 20 lives were lost
and 4 people missing. Therefore, the objective of this paper is to present the results of the post-disaster
investigation, including, the back-analysis of landslides and precipitation due to the typhoon Lionrock. The
rainfall and landslides relat ionship is significantly important for rainfall intensity -duration threshold. For this
typhoon, the empirical rain fall intensity-duration threshold has been derived as I = 20.24D-0.33. The slope
failure could be broadly categorized into the debris flo w, surfic ial erosion, and soil slide, mo reover, occurred
on slopes ranging from 19 to 58 degrees.