NUMERICAL ANALYSIS OF FLOOD AROUND RESIDENTIAL AREA IN THE NIIGATA HEAVY RAINFALL DISASTER ON 7. 13, 2004

Abstract

Flood disaster caused by heavy rainfall occurred in Niigata prefecture on July 13^th, 2004. A numerical study of the flood flow from the Kariyata river in downtown of Nakanosima town, is carried out with fine numerical grid system for two cases of overflow rate from the river. The comparison of real field measurements with the numerical results shows that distribution of flood depth agrees with numerical results qualitatively. Fine tune up of the outflow rate is required for the qualitative agreement. The direction of the flood flow is consistent with the destruction of building structures and houses near the destruction point of the riverbank.