Scientists have for the first time measured the amount of water that pools in the Amazon River floodplain.
A massive 285 billion metric tons, or 285 cubic kilometers of water by volume pools every time the Amazon River floods. That’s equivalent to half the volume of the world’s 15th largest lake, Lake Erie. However, that much water only accounts for about 5% of the water that flows through the Amazon River every year, and the amount is much smaller than researchers were expecting to find.
“Nobody knows exactly how much water there is on the planet,” said Doug Alsdorf, associate professor of earth sciences at Ohio State University. “We need to understand how our water supply will change as the climate changes, and the first step is getting a handle on how much water we actually have. Satellite observations are the only reliable option for places like the Amazon and especially the Congo Basin, where in-person measurements are near-impossible. Just getting there is a serious challenge.”
Alsdorf and his team used four satellites – three from NASA and one from the Japan Aerospace Exploration Agency – to measure the water in the floodplain, that area alongside the Amazon River which overflows during the rainy season. Their focus was the changes in water level during the wet and dry seasons between 2003 and 2006.
The data gathered by the four satellites created a whole picture of the Amazon landscape and how it changes during the rainy season. After the water receded the researchers were able to calculate the change in water volume across the entire floodplain and arrive at measurements of up to an average of 285 cubic kilometers (285 billion metric tons)stored and emptied from the floodplain in a whole year.