In this study, it has been intended to present the ways to improve some problems such as the difficulty
of using the program which had got from the existing study, the computation and application of a lot of parameter
and the complicated processing which need to be more simplified. Also It has been tried to bring up the ways to
make a flood inundation map and a detailed inundation analysis which could reduce the risk factors. We selected an
Anseong-Cheon basin, and wrote a flood inundation scenario based on extreme flood to exceed the planned
frequency to consider only overflow and levee break and executed inundation simulation. Researchers conducted an
analysis of overflow and levee break using function of HEC-RAS Storage with a One-Dimensional model. It applied
Elevation versus Volume Curve for more correct inundation simulation than a method of Area-Time-Depth which
used in popular. This study will suggest a mathematical method of SURFER with a little difference of inundation
area more simplified and precise flood inundation than complicated Arcview 3.2a which used Query method of
Arcview 3.2a.
Keywords : overflow and Levee Break, Query and Mathematical method, Arcview 3.2a, SURFER