Hazard Zone Mapping in Respect to the Damages to Wooden Houses due to Breaking of Levee

Abstract

A numerical simulation method of overland flood flow, in which the effect of buildings and other structures on flow behavior are taken into account is presented to be used in hazard zone mapping in respect to damages to wooden houses. At first, the basic equations and their explicit finite difference expressions are delineated, which assures stable and accurate solutions for overland flood flows. Then a procedure for taking into account the effect of structures on flow behavior is examined. Validity of this simulation method is checked by comparing the results of laboratory model experiments to those obtained through calculations. Subsequently, the criteria for the destruction of wooden houses by a flood flow is discussed. These criteria, combined with the simulation method is used to predict the flood hazardous zones in an actual basin (Ogura basin, situated in the south of Kyoto Prefecture). Finally, we propose a method to estimate the amount of damage by an inundation, and compare the loss calculated under several imaginary bank breach points.