Experimental and Numerical Study of the Effect of Model Geometric Distortion on Laboratory Modeling of Urban Flooding

Abstract

Flooding is a natural hazard with dire economic consequences that can even threaten human lives in extreme cases (Jonkman, 2005). The impact of flooding can become extremely severe particularly in densely populated urban areas. Consequently, the accurate estimation of urban flooding has become an integral component of flood risk management and assessment in times of climate change (Hettiarachchi et al., 2018;Jenkins et al., 2017;Liu et al., 2018) and rapid urbanization (Chen et al., 2015), while it is also needed to support adaptation strategies (Zhou et al., 2018).Urban flooding is a complicated phenomenon due to intricate urban layouts, with flows in various branches meeting in junctions (Riviere et al., 2011;Schindfessel et al., 2015) or being divided in bifurcations (El Kadi Abderrezzak et al., 2011;Momplot et al., 2017). Hence, urban flooding needs to be modeled at least as two-dimensional (2D) shallow flow (Arrault et al., 2016;Mignot et al., 2006) without any further simplifications, such as those that can be done in, for example, river flooding in more rural areas (Kitsikoudis et al., 2020).

Laboratory modelling of urban flooding

“…The datasets presented here complements analyses detailed in two recent papers by Li et al (2021, 2021a) 9 , 12 . The original contributions of the present datasets in these studies are twofold: Quantify for the first time the effect of model geometric distortion on flow characteristics in laboratory models of urban flooding at the district level 9 – 11 , 13 (Dataset 1).…”

“…The datasets presented here complements analyses detailed in two recent papers by Li et al (2021, 2021a) 9 , 12 . The original contributions of the present datasets in these studies are twofold: Quantify for the first time the effect of model geometric distortion on flow characteristics in laboratory models of urban flooding at the district level 9 – 11 , 13 (Dataset 1). Measurements of flow depths at street inlets and flow discharge at street outlets were carried for three layouts of streets: a junction, a bifurcation and a simplified urban district.…”

“…To investigate the effect of model geometric distortion on the observed flow variables, we defined several prototype-scale flooding scenarios, and each of them was reproduced at the model scale using a range of vertical scale factors e V (i.e. the ratio between vertical dimensions at the prototype-scale and the model scale) 9 . At least two different flooding scenarios were tested for each geometric distortion value by varying the inflow discharges and/or the flow depths at the model outlets.…”

“…The geometric distortion enables reducing the relative errors in the measurements and ensures a turbulence regime in the scale model more representative of the regime at the prototype scale. However, the flow aspect ratio is altered by geometric distortion 9 – 11 .…”

“…Quantify for the first time the effect of model geometric distortion on flow characteristics in laboratory models of urban flooding at the district level 9 – 11 , 13 (Dataset 1). Measurements of flow depths at street inlets and flow discharge at street outlets were carried for three layouts of streets: a junction, a bifurcation and a simplified urban district.…”