単一斜面雨水流モデルにおけるショックフロントの発生・追跡に関する基礎的解析

Abstract

As a part of fundamental studies approaching to the effect estimation problems ofnonuniformity of input and field in runoff analysis, properties of shock front in kinematicwave routing of one-dimensional overland flow, especially the locus in time-space plane, water depths in the front and the occurrence conditions are analytically investigated usingthe characteristic method and law of mass conservation after normalization of variables forthe following three model cases; A. given stepwise downwards decreasing distribution ofinput(effective rainfall) on a physically uniform slope, B. given rainyarea moving downwardsin a constant speed on a physically uniform slope, and C. given exponent-type downwardsdecreasing distribution of input and/or flow-coefficient (a in q=ah m).The general equations of locus and depth of front and the occurrence conditions areobtained for the case A and B, but only the sufficient conditions of non-occurrence ofshock are obtained for the case C. Some these results could play the role of checkingor improvement of some numerical methods for shock wave computation, too.