吉野川の出水特性について

Abstract

The purpose of this paper is to show a general approach to disclose the characteristicsof flood runoff in the case where the areal distribution of storm rainfall and the physical pro-perties of a drainage basin are considerably biased, by the use of an example of the YoshinoRiver basin which locates in the upstream area of the Kino River.After examining the several characters of areal distribution of rainfalls and the slope andlength of mountain slope in the basin by the obrerved data and the topographical map, themethod to divide the basin into several sub-basins is presented. The divided sub-barmn iscalled as a unit-basin, in which it might be assumed that various choracters are similar in theviewpoint of runoff analysis during a flood.The Yoshino River basin, 487 km in area, is divided five unit-basins, and the character-istics of flood runoff in the basin is summarily clarified by synthesizing hydrographa from eachunit-basin, calculated by the use of the equation of continuity of rainwater and the relationshipbetween the stored water in the basin and the discharge from it.