雨水流モデルの集中化に関する基礎的研究

Abstract

The kinematic wave flow model, which is a distributed runoff model, is transformedinto a lumped runoff model which we call a "reservoir cascade" model.The reservoir cascade model is obtained through the following procedure: the flow fieldis partitioned into a number of sections; the relation of the discharge at the end of eachsection and the storage within the section is determined by assuming that the water-surfaceprofile can be approximated by that in a steady state; each section is regarded as a reser-voir having the above storage-discharge relation, and the total system is regarded as acascade of reservoirs.After investigating several methods of partitioning the flow field, we found it prefera-ble to partition the flow field so that the propagation time of rainwater disturbance in asteady state within each section is equal to each other, because it is robust against numericalround-off errors.The relation of the lumping error and the number of reservoirs is clarifyed and is su-mmarized in the form of a figure.