Multihazard simulation for coastal flood mapping: Bathtub versus numerical modelling in an open estuary, Eastern Canada
Multihazard simulation for coastal flood mapping: Bathtub versus numerical modelling in an open estuary, Eastern Canada
复制标题
DOI：
10.1111/jfr3.12505
复制
发表时间：
2019-10-01
影响因子：
4.1
通讯作者：
Sevigny, Caroline
中科院分区：
文献类型：
--
作者：
Didier, David;Baudry, Jeremy;Sevigny, Caroline
由于海平面上升和海冰缩小，加拿大东部圣劳伦斯河口和海湾沿线沿着的洪水风险越来越大。因此，需要采用有效和经过验证的区域尺度沿海洪水绘图方法，包括风暴潮和海浪，以便更好地为增加的危险做好准备。本文比较和验证了两种不同的洪水映射方法：使用XBeach的数值洪水模拟和基于总水位的浴缸映射，强制与复合波和水位事件的多灾害情景。XBeach通过水动力测量进行验证。历史风暴事件的模拟和验证对观测到的洪水数据在一个类似的25公里长的海岸线，使用多个拟合指标。XBeach和浴缸法正确预测了洪水区域（分别为66%和78%），但后者高估了36%的洪水范围。XBeach是一种稍微更强大的洪水映射方法，其拟合度为51%，而浴缸映射为48%。采用浴缸式方法，预计洪水深度将达到0.5米，更多的建筑物容易受到100年一遇洪水的影响。对于区域尺度的海岸管理，尽管两种洪水制图方法的洪水范围相似，但结果表明，XBeach的数值模拟优于浴缸洪水制图。
Coastlines along the St. Lawrence Estuary and Gulf, Eastern Canada, are under increasing risk of flooding due to sea level rise and sea ice shrinking. Efficient and validated regional-scale coastal flood mapping approaches that include storm surges and waves are hence required to better prepare for the increased hazard. This paper compares and validates two different flood mapping methods: numerical flood simulations using XBeach and bathtub mapping based on total water levels, forced with multihazard scenarios of compound wave and water level events. XBeach is validated with hydrodynamic measurements. Simulations of a historical storm event are performed and validated against observed flood data over a similar to 25 km long coastline using multiple fit metrics. XBeach and the bathtub method correctly predict flooded areas (66 and 78%, respectively), but the latter overpredicts the flood extent by 36%. XBeach is a slightly more robust flood mapping approach with a fit of 51% against 48% for the bathtub maps. Deeper floodwater by similar to 0.5 m is expected with the bathtub approach, and more buildings are vulnerable to a 100-year flood level. For coastal management at regional-scale, despite similar flood extents with both flood mapping approaches, results suggest that numerical simulation on with XBeach outperforms bathtub flood mapping.