近世熊本城下町形成の水防災の考え方と現代河川減災計画への応用

抄録

Quantitative evaluation of the flood prevention approaches in Kumamoto castle town in early modern times was very important in order to examine present flood crisis management. The flood prevention approaches were hypothesized as a method in which the flood damage does not expand taking into account the morphological features in Kumamoto castle town, while the spill overtopping allowed. Numerical simulations using one dimensional unsteady flow equation were conducted to confirm the hypothesis. Constructing the discontinuous embankments with different crown levels in the castle town river side was useful for causing the inundation to the opposite banks. The existence of water-level controlling system of Tsuboi River, the catchments of the spills in the castle town, was clarified.