Kinematic Hierarchical Filling-&-Spilling vs. Fully 2D Schemes for Modelling Pluvial Flooding in Urban Areas

Código

I-EBHE0068

Autores

Kay Khaing Kyaw, Valerio Luzzi, Stefano Bagli, Attilio Castellarin

Tema

WG 1.03: Urban Water - Urbanization phenomenon & adequate water management

Resumo

Urban pluvial flooding poses a significant threat to large metropolitan areas due to high population density, infrastructure and property concentration, and the observed increase in the intensity and frequency of severe rainstorms. Complex flood simulation models for assessing pluvial flood risk remain resource-intensive. Several studies have highlighted the potential of fast-processing DEM-based methods, such as Hierarchical Filling-&-Spilling Algorithms (HFSAs), thanks to the increasing accessibility of high-resolution LiDAR DEMs. We have developed a fast-processing HFSA, as part of a web-based digital twin solution for flood risk intelligence (see https://saferplaces.co/), that enables building-by-building pluvial flooding hazard and risk modelling in large urban areas by accounting for spatially distributed rainfall input and infiltration processes through a pixel-based Green-Ampt model. In this study, we upgrade SaferPlaces? HFSA based on kinematic wave approximation to depression points and analysing the impact of flow contributions from one cell to another on the formulation of travel time, as well as the backwater effect in depression-related watershed areas. We present the first applications of the kinematic HFSA, comparing it with two state-of-the-art fully 2D rain-on-grid inundation models (i.e. HEC-RAS and UnTRIM). We discuss the potential and limitations of Saferplaces' upgraded HFSA and identify future research possibilities.