巨椋低平流域の都市化と内水

Abstract

This paper discusses the effects of urbanization of upstream districts on flood runoff and inunda-tion characteristics of down stream low-lying area in the Ogura basin situated in south of KyotoCity. The basin was a quiet suburb agricultural district and the residental districts were onlyfew percent in area before about 1965. In the basin, however, the urbanization is rapidly goingon mainly in hill and high ground zones and urban lots are extended to thirty five percent inarea for these ten years.The flood runoff analyses are performed for heavy rain storms in July, 1972, and Augnst, 1959, under both land states in 1972 and 1959, by applying the kinematic surface runoff modelfor a non-inundation zone and the dynamic tank model developed by the authors for the backwater region of a channel and the inundation zone.The urbanization effects are evaluated quantitatively by the form of changes in the runoffvolume, the peak discharge or water level at a point and the operation time of a pump. It isalso mentioned of the flood control effect of paddy field extant along the River Furu which isthe drainage channel of hill and high ground zones.