境界条件による洪水流の変形に関する研究(第1報)

Abstract

In this paper, propagation of flood wave through backwater reach is discussed by theexperiments conducted in the experimental flume of flood wave (1 50m in length, 60 cm in width)at the down stream end of which three kinds of weir were set.It is well known that backwater reach can be devided into two regions from the standpointsof practice and of hydraulic behavior.: one is a storage region where the water level is nearlyhorizontal, and the other is a transition region which exists between storgage region anduniform reach upstream.Flood propagation through backwater reaches is gen?rally estimated by the graphical solu-tion of storage equation under assuming that any deformation of the discharge hydrograph doesnot occur in the transition region.The above treatment has practically sufficient accuracy for the case having a large storageregion such as a large reservoir, but it has no good accuracy for the case that the transitionregion has much effect.The authors studied the propagation of flood wave in such a case, and discussed thevarious kinds of characteristics such as the length of storage reach, deformation of stage andof discharge hydrograph, stage-discharge relationship and celerity of propagation of stagemax. and of discharge max.