Simple and Fast method for Flood Inundation Mapping

Name: Simple and Fast method for Flood Inundation Mapping
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Flood Inundation Mapping using HAND Method

Created byAsghar Azizian

Last updated 5/2024

English

What you'll learn

How to download DEMs from different DEM sources
How to use HAND software and create HAND raster
How to calculate Rating curve for a river reach
How to extract Flood Inundated extents for a specific flood value
How to extract Flood Depth raster for a specific flood value

Course content

1 section • 5 lectures • 1h 20m total length

Introduction to the Hight Above Nearest Drainage (HAND) Model16:30
The Height Above Nearest Drainage (HAND), first introduced by Renno et al. 2008, is a hydrological terrain analysis method, which has been used for flood hazard mapping, flood susceptibility and hydrological modeling in different parts of the world (Rodda, 2005; Huang et al. 2017; Afshari et al. 2018; Zheng et al. 2018). In this method, vertical distance between a cell in topography map and the nearest cell along a river that it drains into defines the HAND value (Afshari et al. 2018). All grid-cells on the topography map that have a HAND value lower than specified water level are considered as inundated.
Download DEMs from different DEM Sources and Calculation of Rating Curve13:44
In this section, you will learn how to download a DEM for your case study and then how to extract the rating curve for a river reach using a simple approach (Hydraulic Toolbox).
Calculation of Rating Curve and Extraction of Flood extents12:56
In this section, you will learn how to calculate the creating curve for a river reach using the Hydraulic Toolbox. After that, you can use this curve and flood values (for different return periods) for the estimation of flood depth. Finally, based on the flood depth, you can estimate the flood extent.
Estimation of Flood Depth Raster using HAND Method6:47
In this section, you will learn how to calculate the flood depth raster for a specific flood value. It means that instead of running a hydraulic model such as HEC-RAS, you can use the HAND method to estimate the flood depth easily and in a fast way, which is important for data-limited regions and emergency case studies.
How to Download RS based DEMs using Open Topography site30:37
This is the complimentary video to assist you in downloading the RS-based DEMs such as SRTM, and ALOS.

Requirements

Minimum Knowledge about GIS, Flood, River engineering

Description

Flooding is one of the major natural disasters that affects many parts of the world and has led to huge amounts of property damages and human life losses, especially in developing countries (Wilby et al., 2008; Cook and Merwade, 2009; Spence et al., 2011; Arnell and Gosling, 2016; Liu et al., 2017). Over the past decades, several hydraulic models have been developed and integrated with geographic information systems (GIS). The performance of these models depends on several factors and running a hydraulic model for a river reached can be complicated especially for data-limited regions. Instead of using these models for the estimation of flood extent and flood depth, we can use a simple and fast method called the HAND method for this issue.

The Height Above Nearest Drainage (HAND), first introduced by Renno et al. 2008, is a hydrological terrain analysis method, that has been used for flood hazard mapping, flood susceptibility, and hydrological modeling in different parts of the world (Rodda, 2005; Huang et al. 2017; Afshari et al. 2018; Zheng et al. 2018). In this method, the vertical distance between a cell in a topography map and the nearest cell along a river that it drains into defines the HAND value (Afshari et al. 2018). All grid cells on the topography map that have a HAND value lower than the specified water level are considered inundated.

Who this course is for:

Flood and River engineers, Researchers, Students and all who are working in flood issues