Gusyev M.,National Graduate Institute for Policy Studies |
Gadeke A.,German Federal Institute of Hydrology BfG Koblenz Germany |
Cullmann J.,German Federal Institute of Hydrology BfG Koblenz Germany |
Magome J.,Yamanashi University |
And 3 more authors.
Journal of Flood Risk Management | Year: 2016
This flood hazard study is the first step towards linking global and local scales of flood risk assessment under the International Flood Initiative (IFI) Flagship Project. To simulate river discharges, we utilised a 600-arcsec grid block-wise TOP (BTOP) model to represent the global scale and constructed a local scale 15-arcsec grid BTOP model for the Rhine River basin. Both BTOP models showed similar statistical performances with observed daily river flows, especially for the 1993 and 1995 floods. For both scales, we calculated flood peak discharges using the Gumbel distribution with L-moments in R from the simulated BTOP daily discharges. The obtained flood peak discharges of both scales were comparable with available gauging station records. For the flood inundation simulation, the 600-arcsec flood peaks were disaggregated to the 15-arcsec scale as input to the Flood Inundation Model (FID), and the resulting 15-arcsec FID maps of 10-, 100- and 200-year return periods had similar extents with the existing official flood hazard maps of high, medium and low probability floods, respectively. These preliminary results demonstrate the possibility of obtaining an acceptable flood hazard assessment on a global scale and serve as a starting point for connecting global and local scales of flood risk assessment. © 2016 The Chartered Institution of Water and Environmental Management (CIWEM) and John Wiley & Sons Ltd.
Sayama T.,International Center for Water Hazard and Risk Management Public Works Research Institute Tsukuba Japan |
Tatebe Y.,International Center for Water Hazard and Risk Management Public Works Research Institute Tsukuba Japan |
Tanaka S.,Kyoto University
Journal of Flood Risk Management | Year: 2015
A devastating flood disaster occurred in Thailand in 2011. In case of such large-scale flooding, it is important to predict the dynamics of inundation on a near real-time basis for safe evacuation. To predict widespread inundation, where both rainfall-runoff from surrounding mountains and rainfall on floodplains contribute to the event, this paper applied a rainfall-runoff-inundation (RRI) model to the entire Chao Phraya River basin (160000km2). Near real-time simulation was conducted for emergency responses with globally available dataset including satellite-based topography (HydroSHEDS derived from SRTM) and rainfall (TRMM 3B42RT) during the disaster. Post-flood simulation was also carried out with more local information. The RRI model was found capable of representing the peak inundation extent with an acceptable accuracy and correctly predicting a 1-month lasting inundation in the lower part of the basin. On the other hand, the prediction overestimated the river discharge by 40% and the inundation water level by 2m mainly due to the neglect of the evapotranspiration effect. The post-flood simulation improved its accuracy by up to 10% for river discharges and 1m for peak inundation water levels, but it did not lead to better agreement of flood extents with those based on the remote sensing. Further study is recommended to improve accuracy for modelling of spatial extent of flooding. Furthermore, sensitivity analysis with different input suggested what information should be prioritised for emergency response-type flood simulations. © 2015 The Chartered Institution of Water and Environmental Management (CIWEM) and John Wiley & Sons Ltd.
Shrestha B.B.,International Center for Water Hazard and Risk Management Public Works Research Institute Tsukuba Japan |
Okazumi T.,Overseas Project Division Policy Bureau Ministry of Land |
Miyamoto M.,International Center for Water Hazard and Risk Management Public Works Research Institute Tsukuba Japan |
Sawano H.,International Center for Water Hazard and Risk Management Public Works Research Institute Tsukuba Japan
Journal of Flood Risk Management | Year: 2015
In this study, a flood damage assessment method was proposed for the assessment of flood risk in data-poor river basins by using a physical-based numerical model, satellite-based information and socio-economic factors. The Pampanga river basin of the Philippines was selected for the case study. For the flood damage assessment, hazard characteristics, such as flood depth and duration, were computed using the rainfall runoff inundation model. Agriculture and households, which are major exposures in flood-prone areas, were taken into account for the flood damage assessment. The potential damage to agriculture was estimated by using the damage functions of agriculture and flood characteristics. The damage functions of agriculture for each growing stage were defined as the function of flood depth and duration. Field investigations and questionnaire surveys were conducted at the selected barangays (villages) in the Pampanga river basin to develop a methodology for household damage estimation. The damage estimation approach for damage to household buildings including assets, was developed based on the flood and household characteristics. The potential damage to house building and assets was estimated. The estimated damage of agriculture and households was compared with the reported values. © 2015 The Chartered Institution of Water and Environmental Management (CIWEM) and John Wiley & Sons Ltd.