THE HISTORICAL TRANSITION AND CHARACTERISTIC OF REVISED ELEMENTS ABOUT THE BASIC FLOOD DISCHARGE IN JAPAN

Abstract

In Japan, the Flood Control Plan is designed by the Basic Flood Discharge (BFD), which is the hydrograph at a designated point in river. Also, flood control facilities should be designed based on the BFD requirement. The Flood Control Plan method of fulfilling BFD has been used since the Meiji-era (1868-1912), and the BFD has been continuously updated according to the situations of social, economical or technical development for each era. In this study, we investigate the historical transition of the revisions of BFD in all Class A rivers from the 1st Flood Defense Plan (1910) to the revised River Law (1997), and classify the revisions into 5 elements by the revised reason of BFD. We discuss the characteristics of the historical transition of BFD revisions and revised reason with the historical background for each era.