Flood Inundation Modeling by Integrating HEC–RAS and Satellite Imagery: A Case Study of the Indus River Basin

Abstract

Floods are brutal, catastrophic natural hazards which affect most human beings in terms of economy and life loss, especially in the large river basins worldwide. The Indus River basin is considered as one of the world’s large river basins, comprising several major tributaries, and has experienced severe floods in its history. There is currently no proper early flood warning system for the Indus River which can help administrative authorities cope with such natural hazards. Hence, it is necessary to develop an early flood warning system by integrating a hydrodynamic model, in situ information, and satellite imagery. This study used Hydrologic Engineering Center–River Analysis System (HEC–RAS) to predict river dynamics under extreme flow events and inundation modeling. The calibration and validation of the HEC–RAS v5 model was performed for 2010 and 2015 flood events, respectively. Manning’s roughness coefficient (n) values were extracted using the land use information of the rivers and floodplains. Multiple combinations of n values were used and optimized in the simulation process for the rivers and floodplains. The Landsat 5 Thematic Mapper (TM), Landsat 8 Operational Land Imager (OLI), Moderate Resolution Imaging Spectroradiometer (MODIS) MOD09A1, and MOD09GA products were used in the analysis. The Normalized Difference Water Index (NDWI), Modified NDWI1 (MNDWI1), and MNDWI2, were applied for the delineation of water bodies, and the output of all indices were blended to produce standard flood maps for accurate assessment of the HEC–RAS-based simulated flood extent. The optimized n values for rivers and floodplains were 0.055 and 0.06, respectively, with significant satisfaction of statistical parameters, indicating good agreement between simulated and observed flood extents. The HEC–RAS v5 model integrated with satellite imagery can be further used for early flood warnings in the central part of the Indus River basin.

Deep Neural Networks Hydrologic and Hydraulic Modeling in Flood Hazard Analysis

“…Flood inundation modeling is crucial in giving the correct information about potential impending oods, which is vital to issuing ood warnings. Engineers, planners, and governmental organizations use ood inundation mapping as a crucial tool for several studies, such as planning municipal and urban growth, emergency response plans, and ood insurance rates [45]. Precise topographic information about rivers and oodplains is required to simulate ood propagation throughout the oodplain accurately, and inundation modeling [46].…”

Disparidad entre cartografías oficiales de peligrosidad y eventos reales: análisis de posibles causas. Estudio de caso en el río Campanillas (Málaga)

“…Investigaciones Geográficas, 81, 51-70 la combinación de modelos con imágenes de satélite (Afzal et al, 2022) o la utilización de redes neuronales artificiales (Chu et al, 2019). No obstante, los modelos numéricos hidrológicos-hidráulicos suelen ser los más habituales para la modelización de inundaciones (Patel et al, 2017, Costabile et al, 2020Ongdas et al, 2020).…”

Charting the Course to Resilience: Hydrodynamic Modeling for Socio-economic Insights for Flood Risk Management in Nepal’s Ungauged Roshi River Catchment

“…These calamities occur when water surpasses the capacity of natural structures like rivers, lakes, and dams, inundating nearby floodplains (Merz et al, 2021;Namara et al, 2022). Due to population growth and economic development in flood-prone areas, flood exposure is projected to increase by 2050, leading to more casualties and damage (Afzal et al, 2022;Merz et al, 2021). Between 2000 and 2019, global flood damages reached a staggering $651 billion (Tellman et al, 2021).…”

“…Mapping the spatial distribution of hydraulic charac-teristics aids in creating flood inundation maps, offering insights into flow depths, patterns, and water movement toward floodplains (Hosseiny et al, 2020;Namara et al, 2022;Pinos and Timbe, 2019). Accurate representation of river geometry, including channels, banks, flow paths, and topography, is crucial for one-dimensional hydrodynamic modeling, focusing on horizontal river paths and flood areas (Afzal et al, 2022;Sarchani et al, 2020). The Hydrologic Engineering Center-River Analysis System (HEC-RAS), developed by the US Army Corps, serves as an invaluable tool for river system modeling, integrating geographic information (Afzal et al, 2022;Aryal et al, 2020;Zotou et al, 2022).…”

“…Accurate representation of river geometry, including channels, banks, flow paths, and topography, is crucial for one-dimensional hydrodynamic modeling, focusing on horizontal river paths and flood areas (Afzal et al, 2022;Sarchani et al, 2020). The Hydrologic Engineering Center-River Analysis System (HEC-RAS), developed by the US Army Corps, serves as an invaluable tool for river system modeling, integrating geographic information (Afzal et al, 2022;Aryal et al, 2020;Zotou et al, 2022). Our study employed HEC-RAS to model the Roshi River in the mid-hills of Nepal originating from the foothills of Phulchowki, characterized by steep slopes and high erosive capacity downstream (Poudel et al, 2012).…”