Flood Hazard Mapping Combining Hydrodynamic Modeling and Multi Annual Remote Sensing data
Flood Hazard Mapping Combining Hydrodynamic Modeling and Multi Annual Remote Sensing data
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DOI：
10.3390/rs71014200
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发表时间：
2015-10-01
期刊：
影响因子：
5
通讯作者：
Matgen, Patrick
中科院分区：
文献类型：
--
作者：
Giustarini, Laura;Chini, Marco;Matgen, Patrick
本文探索了一种将大规模洪水模型的时间和空间连续性与不连续卫星微波观测相结合的方法，用于高分辨率洪水灾害绘图。这种方法背后的假设是，通过连续空间分布的水动力模型计算出的水力变量和作为离散卫星得出的洪水范围观测到的水力变量在时间上是相关的，因此可以将概率从模型系列转移到观测结果。因此，先决条件是建模变量（即洪水范围或水量）与同步观测的洪水范围之间存在显着相关性。如果是这种情况，则长时间内模型模拟的可用性可以对不超标概率进行稳健估计，该概率可归因于相应的同步可用卫星观测。生成的洪水灾害图的空间分辨率与卫星图像相当，高于目前可用的大比例尺洪水模型。该方法被应用于塞文河（英国），使用欧洲中期天气预报中心提供的全球洪水模型的输出和大量 ENVISAT ASAR 图像。用所提出的方法和更传统的数值建模方法获得的灾害图之间的比较支持了这样的假设：如果有足够数量的遥感图像可用，并且从全球模型得出的变量和从卫星观测获得的变量之间存在时间相关性，则将模型结果和卫星观测相结合可以为高分辨率洪水灾害图提供优势。
This paper explores a method to combine the time and space continuity of a large-scale inundation model with discontinuous satellite microwave observations, for high-resolution flood hazard mapping. The assumption behind this approach is that hydraulic variables computed from continuous spatially-distributed hydrodynamic modeling and observed as discrete satellite-derived flood extents are correlated in time, so that probabilities can be transferred from the model series to the observations. A prerequisite is, therefore, the existence of a significant correlation between a modeled variable (i.e., flood extent or volume) and the synchronously-observed flood extent. If this is the case, the availability of model simulations over a long time period allows for a robust estimate of non-exceedance probabilities that can be attributed to corresponding synchronously-available satellite observations. The generated flood hazard map has a spatial resolution equal to that of the satellite images, which is higher than that of currently available large scale inundation models. The method was applied on the Severn River (UK), using the outputs of a global inundation model provided by the European Centre for Medium-range Weather Forecasts and a large collection of ENVISAT ASAR imagery. A comparison between the hazard map obtained with the proposed method and with a more traditional numerical modeling approach supports the hypothesis that combining model results and satellite observations could provide advantages for high-resolution flood hazard mapping, provided that a sufficient number of remote sensing images is available and that a time correlation is present between variables derived from a global model and obtained from satellite observations.