This study aims at examining the transition of land use in the flood area caused by the heavy rain event of July 2018 by using topographic maps and clarifying the increasing factor of flood damage. Findings are as follows; (1) most of land use in the flood area was originally farmland (2) it is likely that the farmland diversions conducted after 1968 may be the factor on increasing the damage caused by flood (3) there are also the areas which the land use in flood area has not almost changed from farmland since 1898.
