農地表面流の抵抗係数に関する一実験的研究

Abstract

There are many complicated hydraulic problems on surface flow over agricultural landsin low areas. This paper deals with the resistance coefficient in transitional flow from inopen channels to at or near state of still water.At first, in order to discuss the variation in resistance coefficient in such flows, the rela-tion between the resistance coefficient and hydraulic factors with respect to the flow at thecritical slope is obtained. The equations (16), (17) and (18) are developed from the exper-imental results using the rectangular open channel.Moreover, the relation between the resistance coefficient and the Froude number isdiscussed. In case of turbulent flow, it is well known that the resistance coefficient increaseswith the Froude number, and here it is also found that the trend of increase in the resistancecoefficient even at the Froude number less than 10 1 is recognized. Since, however, the ex-periment has not been enough to discuss in detail, the definitive conclusion is suspended inthis paper.