中文摘要：

在洪水风险管理中,通常认为逃生距离与淹没水深是灾民避难迁移的控制因素,而洪水泛滥过程以及人员所在位置的时空分布对避难逃生时机与路径选择会产生较大影响。在构建的洪泛区避难逃生路线优化模型中,采用二维水动力学模型,模拟洪泛区的洪水演进过程;采用Dijkstra算法推求最短路线,考虑水流对逃生速度的影响,根据洪水中人体的稳定程度及最迟逃生时刻确定最优避难逃生路线。该模型计算结果能为指导洪泛区灾民逃生及路网选址提供参考依据。以1958年7月和1982年8月兰考东明滩区漫滩洪水为例,分析了漫滩洪水中人体危险程度变化情况,比较了2场洪水中3个受灾点最优避难逃生路线的位置及最迟逃生时刻。计算结果表明：根据最优路线开展逃生将为灾民赢得3-6 h的逃生时间;2场洪水中灾民逃生的最优路线位置相同,可据此适当调整已建路网或规划逃生专用的通道;因1958年洪水的洪峰及水量均较大,所以最迟逃生时间较1982年提前2-3 h。

英文摘要：

The evacuation distance and water depth are regarded as the key factors in flood events, andthe flooding process and the temporal-spatial distributions of victims would influence greatly on the choiceof opportunity and route of evacuation. The model for selecting optimal escape route in flood-prone areas isproposed based on the two-dimensional hydrodynamic model. It would direct the flood victims away fromdanger,but also provide a rational basis for construction of road networks. The Dijkstra algorithm is adopt-ed to derive the shortest routes,the effect of the flood conditions on the escape speed is considered,andthe optimal refuge and escape route is selected based on the stability of the human body and the final es-cape moment. Finally, the optimal escape routes were selected for two overbank flood events in July 1958 and August 1982 in the Lankao-Dongming floodplain area in the Lower Yellow River. The variations ofrisks for people in floodwaters were analyzed,and the locations and corresponding final escape moments ofoptimal escape routes were determined for three disaster locations in these two flood events. The results indi-cate that there would be 3-6 hours more for evacuees if they escape on the optimal routes. The locationsof optimal escape routes for these two flood events were the same,but the final escape moments would beearlier in the 1958 flood event because of the larger amount of water volume and higher peak discharge.