巨椋低平流域の都市化と内水(7)-昭和61年7月豪雨による氾濫とその考察-

Abstract

URBANIZATION EFFECTS ON FLOOD RUNOFF ANDINUNDATION CHARACTERISTICS IN OGURA BASIN (7)-FLOODING PROCESSES CAUSED BY RECORD HEAVY RAINFALL INJULY, 1986 AND COUNTER-MEASURES AGAINST ITS FOOD-By Mutsumi KADOYA and Takao MASUMOTOSynopsisPart of new residential area and low-lying arable land in the Ogura basin located inthe south of kyoto suffered inundation damages caused by record heavy rainfall such as257mm (return period: 1/50years) in 24 hours and 332.5mm(1/l00years) in 48 hours, in July21-22, 1986.To cope with changes of flood runoff due to the rapid urbanization of this area, theimprovement of the River Furu begun in 1971, and the Kumiyama Pump Station with apump of 30m3/s was built at the downstream end of the River Furu in 1973. In additionto those counter-measures, several promising measures have been propsosed in previouspapers4) 6).Almost all of these plans, however, are based upon the states that the improvement ofthe River Furu had been completed. It seems as if the heavy rainfall of this time struckthis weakness of the area to bring the disaster.This paper discusses the flood behavior of this occasion analyzed by the kinematicrunoff model and the diffusive tank model, and effects of urbanization on this flooding toshow the existence of the weak points to be improved. Moreover, several flood control planswhich are expected as the emergency measures are examined by using the rainfall patternof this time.