Author(s): Peng Guo, Junqiang Xia, Roger A. Falconer, Qian Chen
Linked Author(s): Peng Guo
Keywords: Hydrodynamic module, flood-prone areas, human stability, escape speed, escape routes
Abstract: In the current study, a model of selecting optimal escape routes in flood-prone areas is proposed based on the two-dimensional hydrodynamic module capable of simulating flood inundation processes over real terrains, including: evaluation of hazard risk to evacuees, calculation of evacuation time and selection of optimal escape routes. In the proposed model, a formula for the mechanics-based incipient velocity of a human body for toppling instability has been adopted to assess the hazard degrees of evacuees in floodwaters. Empirical curves relating the water depth and corresponding escape speed for adults presented by previous researchers have been used to calculate the cumulative time for escaping. The selection method of optimal escape routes is presented, comprising the schemes A and B for the scenarios with and without the established road networks being considered. Extreme floods have occurred in the Lower Yellow River in July 1958 and August 1982. Thus the proposed model has been applied to selected optimal escape routes during these two overbank flood events in the Lankao-Dongming floodplain. According to the calculations, the following conclusions have been obtained: (i) the variation in hazard degrees for evacuees at different times for overbank flood event in July 1958 have been presented, which would be useful to flood risk management in this floodplain area; (ii) optimal escape routes and corresponding final escape moments have been determined for three starting locations using the schemes A and B for overbank flood event in July 1958, which would provide about 3 h and 5 h more for issuing warnings and evacuation operation; (iii) positions of optimal escape routes for overbank flood events in August 1982 and July 1958 have been almost the same for three starting locations, but the final escape moment for overbank flood event in July 1958 would be earlier because of the larger amount of water volume and higher peak discharge
Year: 2017