昭和47年7月豪雨による東大阪水害とその考察

Abstract

The East Osaka region, middle Japan, was attacked by local heavy rainfall about 300 mmduring July 11-13, 1972, and several places suffered severe disaster from flood. Sum of floodedareas was estimated to be 17.9 k㎡, and the number of submerged houses was calculated as 36, 345.Flooded damage was the most intense in Suminodo district situated near the confluence of theRivers Daiichineya and Onchi.Most part of the East Osaka region is a alluvial fan formed by the Rivers Vodo and Yamato.The region, therefore, was mainly utilized as farms and paddy fields. But considarable part of theregion was being urbanized rapidly regardless of drainage channel conditions in recent.Hydrograph of flooded volume at the confluence of the Rivers Daiichineya and Onchi wasestimated as the difference between inflow from both rivers and outflow to downstream. Thekinematic wave method for runoff analysis was applied to estimate inflow and the modified leap-frogmethod to simulate outflow. The results were fairly good to simulate hydrograph of water levelin flooded area.