27 April, 2021
A recent post by NASA Earth Observatory highlights a study by researchers from the Earth Science Institute. The study shows how remote sensing satellite data enable mapping of desert lakes around the globe. Desert lakes may serve us as large water reservoirs, and are home to a large variety of plants and animals, which depend on floodwater arrival. These lakes aid scientists in deciphering past climatic and environmental conditions, which could then help in interpreting the impact of climate change in the future. To do so, we need to know the exact amount of water these lakes can hold, i.e. we must know the shape and topography of the lake-floor. However, given these lakes are generally dry, empty, and remote, this cannot be done using ships.
The new study enables determining the topography of shallow desert lakes using a combination of two sets of satellite data coming from satellites launched by NASA and the United States Geological Survey: A long series of imagery from the Landsat satellites produced a map showing the global frequency of water occurrence. Short duration floods tend to fill desert lakes rather quickly. The arriving water evaporates slowly, and thus, the deepest parts of these lakes correspond to higher water frequency. Using the relation between the water frequency and precise elevation measurements by an airborne laser on top of NASA’s new satellite: ICESat-2, the researchers were able to map the topography of the lakes’ floor. Using this methodology, researchers can now map such lakes in deserts around the globe, which can help understanding the amount of water resources in deserts, and past, present, and possibly future climate in the lakes’ surroundings.