Abstract
Typhoon Hagibis struck Japan in October 2019, bringing severe damage in the eastern
part of Japan due to heavy rain associated with it. The inundation disaster occurred in the
area surrounded by Tama River, Maruko River, and Yazawa River, which lies on the border
between Setagaya and Ota Wards. In the present paper, the results of the field survey on the
distribution of inundation depths in this area were reported, with the description of the physical
characteristics of the area and the rainfall and water levels in the Tama River basin during
this event. It was found that a large part of the area was inundated, and the inundation depths
were larger in the places where the ground elevation was locally lower than the surroundings
with the maximum inundation depth of more than 2 m. The distribution of inundation heights
indicates that the water was flowing from west to east in this area.
