Estimation of inundation depth using flood extent information and hydrodynamic simulations

Abstract

Inundation depth (or level) is the most basic information for flood risk assessment; however, its mapping suffers from lack of in situ data in many cases. The aim of this study is to propose a new method for estimating inundation depth and spatially distributed water level for a local-scale pluvial flood using a combination of flood extent information derived from remote sensing imagery and hydrodynamic simulations. The study assumes the location of the inundation area given by the remote sensing imagery is mostly, but not completely, reliable. The estimation error of ground surface area wetted by inundation water body (wetted area) is used as an index to determine the most likely distribution of inundation depth. The proposed method was applied to two study areas to examine the performance of the method for different topographic characteristics. It showed promising results with an estimation precision of 0.02 to 0.17 m. An additional experiment suggested that water level could not be correctly estimated without flood extent information, complementing errors of the ground elevation data, and furthermore, using different topographic datasets revealed that the performance was highly influenced by the ground elevation data.

Establishing flood damage functions for agricultural crops using estimated inundation depth and flood disaster statistics in data-scarce regions

“…This study utilizes a method for estimating inundation depth from flood extent information and hydrodynamic simulations proposed by the authors (Nguyen et al, 2016). The method was developed for datascarce regions assuming that hydrometeorological variables, including inundation depth, are rarely observed.…”

“…Among these parameters, this study considers inundation depth as the single variable in damage functions since inundation depth is the easiest parameter to obtain and can be estimated with relatively little uncertainty even in data scarce regions, for example by using the method developed by the authors (Nguyen et al, 2016). The crop growth stage is not parameterized in the current study because this attempt to develop flood damage functions is in an early phase, although the importance of crop growth stage is widely recognized (Citeau, 2003;Todorovic and Woolhiser, 1972), which will obviously narrow the range of applicability of the functions established by the proposed methodolgy.…”

Estimation Method of Inundation Extent Based on Mathematical Morphology

“…It provided prototype solutions for inundation estimation. Combining the flood extent information derived from RS imagery and hydrodynamic simulations, Nguyen et al [2] proposed a model for estimating inundation depth and spatially distributed water level. e model provided more effective assessment for local-scale pluvial flood.…”

“…For the purpose of analyzing the accuracy of different methods, we estimated the inundation depth and inundation extent caused by the Sanhekou Reservoir at water volume of 1910 × 10 6 m 3 and 2349 × 10 6 m 3 , as shown in Table 1. HD represents the hydrodynamic method proposed in the literature [2], SF is the space-filling method put forward in the literature [20], LM is the method of simple expansion indicated in the literature [25], and MM represents the method proposed in this paper.…”

Flood propagation modeling with the Local Inertia Approximation: Theoretical and numerical analysis of its physical limitations

“…(2) has been recently used in a variety of applications, at urban (Neal et al 2011, Martins et al 2016c, Martins et al 2017, basin (Coulthard et al 2013, Cea and Bladé 2015, Savage et al 2016, Nguyen et al 2016), and regional scale (Falter et al 2013, Yamazaki et al 2013, Mateo et al 2017.…”