A novel downstream Flood Hazard Grade Index incorporating upstream Hydrograph Characteristics to predict Debris Flow Runoff

The July 2020 debris flow in Japan caused enormous damage, and briefing sessions on disaster prevention have prompted demands for detailed explanations predictions of such phenomena high-risk areas. It is necessary to obtain four-dimensional risk information, which considers temporal changes risk, rather than limiting the analysis conventionally static information. In this study, we developed a method setting boundary conditions prediction via hazard map using various types digital To understand effects hydrograph characteristics from upstream, discharge was analysed under different conditions, as topography-driven riverbed shear stress, one-dimensional numerical model that water sediment flow. Our results suggested upstream inflow affect flood runoff processes downstream; therefore, separate downstream grade index uses input.