Extreme Floods: Devastating or Ecologically Valuable?

Full description

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

Notes

Significance statement