Abstract
Run-up processes of the 2011 Tohoku tsunami into the city of Kamaishi, Japan, were simulated numerically using 2-D shallow water equations with a new treatment of building footprints. The model imposes an internal hydraulic condition of permeable and impermeable walls at the building footprint outline on unstructured triangular meshes. Digital data of the building footprint approximated by polygons were overlaid on a 1.0m resolution terrain model. The hydraulic boundary conditions were ascertained using conventional tsunami propagation calculation from the seismic center to nearshore areas. Run-up flow calculations were conducted under the same hydraulic conditions for several cases having different building permeabilities. Comparison of computation results with field data suggests that the case with a small amount of wall permeability gives better agreement than the case with impermeable condition. Spatial mapping of an indicator for run-up flow intensity (IF = (hU2)max, where h and U respectively denote the inundation depth and flow velocity during the flood, shows fairly good correlation with the distribution of houses destroyed by flooding. As a possible mitigation measure, the influence of the buildings on the flow was assessed using a numerical experiment for solid buildings arrayed alternately in two lines along the coast. Results show that the buildings can prevent seawater from flowing straight to the city center while maintaining access to the sea.
| Original language | English |
|---|---|
| Pages (from-to) | 1871-1883 |
| Number of pages | 13 |
| Journal | Natural Hazards and Earth System Sciences |
| Volume | 17 |
| Issue number | 11 |
| DOIs | |
| Publication status | Published - Nov 6 2017 |
Fingerprint
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
Cite this
High-resolution modeling of tsunami run-up flooding : A case study of flooding in Kamaishi city, Japan, induced by the 2011 Tohoku tsunami. / Akoh, Ryosuke; Ishikawa, Tadaharu; Kojima, Takashi; Tomaru, Mahito; Maeno, Shiro.
In: Natural Hazards and Earth System Sciences, Vol. 17, No. 11, 06.11.2017, p. 1871-1883.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - High-resolution modeling of tsunami run-up flooding
T2 - A case study of flooding in Kamaishi city, Japan, induced by the 2011 Tohoku tsunami
AU - Akoh, Ryosuke
AU - Ishikawa, Tadaharu
AU - Kojima, Takashi
AU - Tomaru, Mahito
AU - Maeno, Shiro
PY - 2017/11/6
Y1 - 2017/11/6
N2 - Run-up processes of the 2011 Tohoku tsunami into the city of Kamaishi, Japan, were simulated numerically using 2-D shallow water equations with a new treatment of building footprints. The model imposes an internal hydraulic condition of permeable and impermeable walls at the building footprint outline on unstructured triangular meshes. Digital data of the building footprint approximated by polygons were overlaid on a 1.0m resolution terrain model. The hydraulic boundary conditions were ascertained using conventional tsunami propagation calculation from the seismic center to nearshore areas. Run-up flow calculations were conducted under the same hydraulic conditions for several cases having different building permeabilities. Comparison of computation results with field data suggests that the case with a small amount of wall permeability gives better agreement than the case with impermeable condition. Spatial mapping of an indicator for run-up flow intensity (IF = (hU2)max, where h and U respectively denote the inundation depth and flow velocity during the flood, shows fairly good correlation with the distribution of houses destroyed by flooding. As a possible mitigation measure, the influence of the buildings on the flow was assessed using a numerical experiment for solid buildings arrayed alternately in two lines along the coast. Results show that the buildings can prevent seawater from flowing straight to the city center while maintaining access to the sea.
AB - Run-up processes of the 2011 Tohoku tsunami into the city of Kamaishi, Japan, were simulated numerically using 2-D shallow water equations with a new treatment of building footprints. The model imposes an internal hydraulic condition of permeable and impermeable walls at the building footprint outline on unstructured triangular meshes. Digital data of the building footprint approximated by polygons were overlaid on a 1.0m resolution terrain model. The hydraulic boundary conditions were ascertained using conventional tsunami propagation calculation from the seismic center to nearshore areas. Run-up flow calculations were conducted under the same hydraulic conditions for several cases having different building permeabilities. Comparison of computation results with field data suggests that the case with a small amount of wall permeability gives better agreement than the case with impermeable condition. Spatial mapping of an indicator for run-up flow intensity (IF = (hU2)max, where h and U respectively denote the inundation depth and flow velocity during the flood, shows fairly good correlation with the distribution of houses destroyed by flooding. As a possible mitigation measure, the influence of the buildings on the flow was assessed using a numerical experiment for solid buildings arrayed alternately in two lines along the coast. Results show that the buildings can prevent seawater from flowing straight to the city center while maintaining access to the sea.
UR - http://www.scopus.com/inward/record.url?scp=85032976748&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85032976748&partnerID=8YFLogxK
U2 - 10.5194/nhess-17-1871-2017
DO - 10.5194/nhess-17-1871-2017
M3 - Article
VL - 17
SP - 1871
EP - 1883
JO - Natural Hazards and Earth System Science
JF - Natural Hazards and Earth System Science
SN - 1561-8633
IS - 11
ER -