Extreme Floods: Devastating or Ecologically Valuable?

Abstract

Floods are the most common water related disaster, causing widespread devastation, loss of life, and displacement of people. They can also be vital environmental events that many different ecological zones rely upon. Many regions in the world experience floods annually, particularly in the tropics where the wet season rains can result in large, frequent floods. Other regions, particularly in arid parts of the world, experience less regular, but often more severe rainfall events leading to widespread flooding. Many of these regions, however, have very few gauges, and as such, there is very little information on the volume of these floodwaters. Here we show that it is possible through the use of the new Surface Water and Ocean Topography mission (SWOT) to map not just the extent, but the depth of these floodwaters over large, remote regions. We found that using appropriate filtering of the SWOT pixel cloud data, and digital elevation models it is possible to obtain water depth measurements of some major 2025 floods in Pakistan and Australia over hundreds of kilometres. Further, we are able to calculate the volume of these floodwaters in the Chenab, Sutlej, and Ravi rivers in Pakistan, as well as the Diamantina River, Cooper Creek, and Lake Eyre in Australia. This provides previously unknown but valuable information about the quantity of floodwaters in Pakistan and Australia, which is vital for understanding flood severity and the damage caused, but also provides information for ecological studies, as well as agricultural and environmental management.

This study has been submitted to Natural Hazards and a preprint of the article is made available here

Dodd, L. and P. Tregoning, Extreme Floods: Devastating or Ecologically Valuable?, Natural Hazards, submitted April 2026.

Software used in this study are available at https://github.com/lachlan13893/ANU-SWOT-Hydrology-Software

Flood Depth files

Data files containing flood depths for the Queensland floods during March/April 2025 are provided in text files.

Queensland_Flood_Depths_2025_03_28.txt

Queensland_Flood_Depths_2025_03_29.txt

Queensland_Flood_Depths_2025_03_30.txt

Queensland_Flood_Depths_2025_03_31.txt

Queensland_Flood_Depths_2025_04_01.txt

Type
collection
Title
Extreme Floods: Devastating or Ecologically Valuable?
Collection Type
Repository
Access Privileges
Research School of Earth Sciences
DOI - Digital Object Identifier
10.25911/48by-p681
Website Address
https://github.com/lachlan13893/ANU-SWOT-Hydrology-Software
Metadata Language
English
Data Language
English
Significance Statement
Data from the Surface Water and Ocean Topography (SWOT) satellite mission is used to quantify the depth of floods in 2025 which occurred in Pakistan and in central Australia. Flood volumes were estimated and reveal that the level of devastation does not depend upon flood volume.
Brief Description
This manuscript was submitted to the journal "Natural Hazards".
Full Description
Abstract

Floods are the most common water related disaster, causing widespread devastation, loss of life, and displacement of people. They can also be vital environmental events that many different ecological zones rely upon. Many regions in the world experience floods annually, particularly in the tropics where the wet season rains can result in large, frequent floods. Other regions, particularly in arid parts of the world, experience less regular, but often more severe rainfall events leading to widespread flooding. Many of these regions, however, have very few gauges, and as such, there is very little information on the volume of these floodwaters. Here we show that it is possible through the use of the new Surface Water and Ocean Topography mission (SWOT) to map not just the extent, but the depth of these floodwaters over large, remote regions. We found that using appropriate filtering of the SWOT pixel cloud data, and digital elevation models it is possible to obtain water depth measurements of some major 2025 floods in Pakistan and Australia over hundreds of kilometres. Further, we are able to calculate the volume of these floodwaters in the Chenab, Sutlej, and Ravi rivers in Pakistan, as well as the Diamantina River, Cooper Creek, and Lake Eyre in Australia. This provides previously unknown but valuable information about the quantity of floodwaters in Pakistan and Australia, which is vital for understanding flood severity and the damage caused, but also provides information for ecological studies, as well as agricultural and environmental management.

This study has been submitted to Natural Hazards and a preprint of the article is made available here

Dodd, L. and P. Tregoning, Extreme Floods: Devastating or Ecologically Valuable?, Natural Hazards, submitted April 2026.

Software used in this study are available at https://github.com/lachlan13893/ANU-SWOT-Hydrology-Software

Flood Depth files

Data files containing flood depths for the Queensland floods during March/April 2025 are provided in text files.

Queensland_Flood_Depths_2025_03_28.txt

Queensland_Flood_Depths_2025_03_29.txt

Queensland_Flood_Depths_2025_03_30.txt

Queensland_Flood_Depths_2025_03_31.txt

Queensland_Flood_Depths_2025_04_01.txt

Contact Email
paul.tregoning@anu.edu.au
Contact Address
Research School of Earth Sciences The Australian National University
Contact Phone Number
+61 2 6125 5510
Principal Investigator
Lachlan Dodd
Supervisors
Paul Tregoning
Fields of Research
3706 - Geophysics; 370603 - Geodesy; 370704 - Surface water hydrology
Socio-Economic Objective
180308 - Surface water quantification, allocation and impact of depletion; 190404 - Hydrological hazards (e.g. avalanches and floods)
Keywords
floods, SWOT, flood depth, Channel Country, Lake Eyre
Type of Research Activity
Strategic basic research
Date Coverage
2024-01-01
2025-11-01
Geospatial Location
text
Pakistan and central Australia, Lake Eyre
Date of data creation
2026-04-13
Year of data publication
2026
Creator(s) for Citation
Lachlan
Dodd
Publisher for Citation
The Australian National University Data Commons
Retention Period
Indefinitely
Data Size
39 MB
Data Management Plan
No
Status: Published
Published to:
  • Australian National University
  • Australian National Data Service
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