English: April 6, 2023 March 27, 2023

Acquired on April 6 and March 27, 2023, by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite, these two false-color images show rapid changes in water level on the Gascoyne and Murchison Rivers in Western Australia. Simply clicking on the date below the image reveals that both the Gascoyne (north) and the Murchison (south) Rivers were nearly completely dry on March 27. Only 10 days later, on April 6, the rivers were not only visible, but appeared to be flooded.

The Gascoyne and Murchison Rivers are both ephemeral waterways, which contain water only part of the year. They tend to hold water near the end of the rainy season (April) or after heavy rains drench central West Australia, where the rivers or located or their extended basins. Rainstorms have impacted north and central Western Australia recently, especially in late March through early April.

This type of false-color image helps separate water (blue) from open land (tan, brown, or pink tints) and vegetation (green). In the earlier image (March 27), it is easier to see the course of water in ephemeral rivers by the streaks of green that mark vegetation growing wherever water exists rather than blue of the water. This is because water volume is extremely scant, but enough to support growth of tenacious plants.