In this study, the application of the resilience concept of the flood event depending on progress of the time is analyzed as the hazard occurrence, the disaster risk, the damage risk, and the evolution of the damages....In this study, the application of the resilience concept of the flood event depending on progress of the time is analyzed as the hazard occurrence, the disaster risk, the damage risk, and the evolution of the damages. Flood disaster is defined as the occurrence of an inundation in an exposed area. The human exposure (loss of life, injury, …), structural (buildings, roads, …) and functional (economic, political, … functions of an area) economic exposure cause high risk of damage if the area in which the hazard occurs is at low resilience. Furthermore the damage will increase without adequate response against disaster. The flood disaster risk is decreased by flood control measures, reducing structural and functional exposure. Non-structural measures, such as appropriate prior-evacuation, decrease the human exposure to flood disaster. This study reviews the events of 2000 and 2011 floods in the Shonai River basin in Japan to help assess resilience to flood disaster. These two events had the same type of hazards in intensity and location, allowing the study in terms of adaptation to flood disaster in the river basin to focus on the structural and nonstructural effort to increase resilience of the disaster depending on progress of the time.展开更多
The study focused on the application of Flood Routing Models for Flood Mitigation in Orashi River, South-East Nigeria. Flood data were collected for the study area and subjected to statistical analysis. Three flood Ro...The study focused on the application of Flood Routing Models for Flood Mitigation in Orashi River, South-East Nigeria. Flood data were collected for the study area and subjected to statistical analysis. Three flood Routingmodels were comparatively applied including Muskingum model, Level Pool model and Modified Pul’s model. Assumed routing period of 2.3 hours which helped to check excessive flood at the downstream section of the river was used. Also a dimensionless weighting factor of 0.15 was also adopted. Muskingum model and Level Pool model which represent linear relationship between measured outflow and predicted outflow for specified inflow and time change of one hour gave high and positive values of coefficients of correlations of 0.9769 and 0.9732 respectively. The Modified Pul’s model which also represents a linear relationship between measured outflow and predicted outflow for specified inflow and a time change for one hour showed the highest coefficient of correlation of 0.9984 and lowest standard error of 0.1749. Though, flood models of the Muskingum method and Level Pool method exhibited good correlation, their prediction differed significantly with the corresponding models of original data sets because of high standard error and thus not adequate for field application in similar rivers. A design application was carried out using the Modified Pul’s model. The values obtained for routed storage capacity was 348 m3 while the designed capacity was 354 m3. It is recommended that dredging of the river is carried out to achieve the designed capacity. This would eliminate the risk of flooding. The results of the study will serve useful purposes in predicting flood events and design of flood control works in similar basins.展开更多
文摘In this study, the application of the resilience concept of the flood event depending on progress of the time is analyzed as the hazard occurrence, the disaster risk, the damage risk, and the evolution of the damages. Flood disaster is defined as the occurrence of an inundation in an exposed area. The human exposure (loss of life, injury, …), structural (buildings, roads, …) and functional (economic, political, … functions of an area) economic exposure cause high risk of damage if the area in which the hazard occurs is at low resilience. Furthermore the damage will increase without adequate response against disaster. The flood disaster risk is decreased by flood control measures, reducing structural and functional exposure. Non-structural measures, such as appropriate prior-evacuation, decrease the human exposure to flood disaster. This study reviews the events of 2000 and 2011 floods in the Shonai River basin in Japan to help assess resilience to flood disaster. These two events had the same type of hazards in intensity and location, allowing the study in terms of adaptation to flood disaster in the river basin to focus on the structural and nonstructural effort to increase resilience of the disaster depending on progress of the time.
文摘The study focused on the application of Flood Routing Models for Flood Mitigation in Orashi River, South-East Nigeria. Flood data were collected for the study area and subjected to statistical analysis. Three flood Routingmodels were comparatively applied including Muskingum model, Level Pool model and Modified Pul’s model. Assumed routing period of 2.3 hours which helped to check excessive flood at the downstream section of the river was used. Also a dimensionless weighting factor of 0.15 was also adopted. Muskingum model and Level Pool model which represent linear relationship between measured outflow and predicted outflow for specified inflow and time change of one hour gave high and positive values of coefficients of correlations of 0.9769 and 0.9732 respectively. The Modified Pul’s model which also represents a linear relationship between measured outflow and predicted outflow for specified inflow and a time change for one hour showed the highest coefficient of correlation of 0.9984 and lowest standard error of 0.1749. Though, flood models of the Muskingum method and Level Pool method exhibited good correlation, their prediction differed significantly with the corresponding models of original data sets because of high standard error and thus not adequate for field application in similar rivers. A design application was carried out using the Modified Pul’s model. The values obtained for routed storage capacity was 348 m3 while the designed capacity was 354 m3. It is recommended that dredging of the river is carried out to achieve the designed capacity. This would eliminate the risk of flooding. The results of the study will serve useful purposes in predicting flood events and design of flood control works in similar basins.
