Using High-Density LiDAR Data and 2D Streamflow Hydraulic Modeling to Improve Urban Flood Hazard Maps: A HEC-RAS Multi-Scenario Approach

Alin Mihu-Pintilie,Larisa Elena Paveluc,Cristian Constantin Stoleriu,Martín Núñez Pérez,Cătălin Ioan Cîmpianu

doi:10.3390/w11091832

Alin Mihu-Pintilie, Larisa Elena Paveluc + Show 3 more

Open Access

https://doi.org/10.3390/w11091832

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Abstract

The ability to extract streamflow hydraulic settings using geoinformatic techniques, especially in high populated territories like urban and peri-urban areas, is an important aspect of any disaster management plan and flood mitigation effort. 1D and 2D hydraulic models, generated based on DEMs with high accuracy (e.g., Light Detection and Ranging (LiDAR)) and processed in geographic information systems (GIS) modeling software (e.g., HEC-RAS), can improve urban flood hazard maps. In this study, we present a small-scale conceptual approach using HEC-RAS multi-scenario methodology based on remote sensing (RS), LiDAR data, and 2D hydraulic modeling for the urban and peri-urban area of Bacău City (Bistriţa River, NE Romania). In order to test the flood mitigation capacity of Bacău 1 reservoir (rB1) and Bacău 2 reservoir (rB2), four 2D streamflow hydraulic scenarios (s1–s4) based on average discharge and calculated discharge (s1–s4) data for rB1 spillway gate (Sw1) and for its hydro-power plant (H-pp) were computed. Compared with the large-scale flood hazard data provided by regional authorities, the 2D HEC-RAS multi-scenario provided a more realistic perspective about the possible flood threats in the study area and has shown to be a valuable asset in the improvement process of the official flood hazard maps.

Highlights

In the last decades, with climate change and global warming, the associated natural disasters have reached more disastrous and catastrophic scales [1,2,3,4,5,6]
We developed a method for flood vulnerability assessment under real and mathematical hydrological data based on HEC-RAS, Light Detection and Ranging (LiDAR) data, and 2D hydraulic modeling
Different from other studies [23,24,25,26,27,47], which provide flood hazard maps based on hydrological data calibrated at river basin scale [23,24,26,27], we developed for the first time in the study area flood hazard maps adapted to local environment settings and calculated discharge

Summary

Introduction

With climate change and global warming, the associated natural disasters have reached more disastrous and catastrophic scales [1,2,3,4,5,6]. The intensification of the hydrological cycle has made an unprecedented impact on the magnitude, spatial extend, duration and frequency of hydro-meteorological disaster events [10,11,12]. Supporting this statement, many scientific publications support the fact that the occurrence of climate-related disasters (e.g., mainly floods, severe storms, cyclones, typhoons, droughts) have significantly increased under the abrupt changes in hydrological climatic conditions, the ecosystems resilience to transitional (wet–dry), and other related. Among them, flooding phenomena are the most widespread, frequent, and costly natural disaster for the human societies [18,19], and is the most common natural hazard and the third most damaging hazard globally after storms and earthquakes [20,21]

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