Navigation Links
First satellite measurement of water volume in Amazon floodplain
Date:8/5/2010

COLUMBUS, Ohio For the first time, scientists have been able to measure the amount of water that rises and falls annually in the Amazon River floodplain.

The result -- 285 billion metric tons, or 285 cubic kilometers of water by volume -- sounds like a lot. That amount is over half the volume of Lake Erie, which is the world's 15th largest lake.

But it accounts for only 5 percent of the water flowing through the Amazon River every year, and it is a much smaller amount than researchers were expecting to find in the largest drainage basin in the world.

Doug Alsdorf, associate professor of earth sciences at Ohio State University, and his colleagues report their study online in the journal Remote Sensing of Environment, in a paper to appear in a future print edition.

Until now, researchers could only estimate the amount of water in the Amazon floodplain using a few sporadic field studies and crude assumptions about water flow. In fact, water volumes on any floodplain are poorly known, if at all. Yet this information is critical to predicting the floods and droughts that could accompany global climate change, explained Alsdorf.

Much of Earth's available fresh water resides in remote rivers, lakes and wetlands, and also underground.

"Nobody knows exactly how much water there is on the planet," he said. "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."

Alsdorf and his team have made it their mission to find ways to measure water from space.

"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," he said.

For this study, the researchers were interested only in the amount of water that flowed into and out of the floodplain -- that is, the amount of water that spilled onto land when the Amazon River overflowed its banks during the rainy season.

Alsdorf and his team used four satellites -- three NASA satellites and one from the Japan Aerospace Exploration Agency -- to get the first direct measure of water in the floodplain.

They combined data from the Gravity Recovery and Climate Experiment, the Global Precipitation Climatology Project, the Shuttle Radar Topography Mission, and the Japanese Earth Resources Satellite. They focused on measuring water level changes during the wet and dry seasons between 2003 and 2006.

Taken together, these satellites gave a picture of how the Amazon landscape changed as highland rains surged through the river's many tributaries and the resulting overflow spilled into the lowland jungle. After the water receded, they calculated the change in volume along the floodplain.

These calculations haven't been made before, in part due to the immense difficulty of combining different kinds of data in a reliable way. The researchers had to meld gravity readings -- a measure of the flood water's mass -- with radar and optical measurements of the water level and extent of the floodplain.

The measurements added up to an average of 285 cubic kilometers (285 billion metric tons) of water stored and emptied from the floodplain in a year.

At the height of the rainy season, water flowed into various locations on the Amazon floodplain at a rate of 5,500 cubic meters (5,500 metric tons) per second, and during the dry season, it drained away into the Amazon River -- and, ultimately, into the Atlantic Ocean at a rate of 7,500 cubic meters (7,500 metric tons) per second.

The floodplain total, however large, represents only 5 percent of the amount that scientists believe is emptying from the Amazon River into the ocean every year.

To Alsdorf, the finding begs the question of exactly how much water is flowing through the Amazon system, and it underscores the many unknowns that scientists must confront as they work to understand climate change.

The Amazon, however grand in size, is just one river basin among countless basins around the planet -- each vital to the soil quality and water quality of its surroundings, he said.

Future measurements should be easier with the Surface Water and Ocean Topography (SWOT) mission, which aims to take stock of all the world's water. Alsdorf co-leads the science team for the SWOT satellite, which NASA has set to launch in 2020.


'/>"/>

Contact: Doug Alsdorf
Alsdorf.1@osu.edu
614-247-6908
Ohio State University
Source:Eurekalert

Related biology news :

1. Genome of ancient sponge reveals origins of first animals, cancer
2. First nearshore survey of Antarctic krill reveals high density, stable population in shallow waters
3. Discovered: Audubons first engraving of a bird
4. First step toward electronic DNA sequencing: Translocation through graphene nanopores
5. First-of-its-kind map details the height of the globes forests
6. NTU gets GreenLite for Singapores first truly eco-friendly bus
7. InQ Biosciences Introduces First Fully Integrated Cell Research System
8. First of its kind: WSU led Bio-Jet fuel project officially gets off the ground
9. Flemish researchers provide the first experimental evidence of dynamic allostery in protein regulation
10. Bacterial diversity of Tablas de Daimiel studied for first time
11. First preliminary profile of proteins in bed bugs saliva
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/5/2017)... SEATTLE , April 5, 2017  The Allen ... the Allen Cell Explorer: a one-of-a-kind portal and dynamic ... large-scale 3D imaging data, the first application of deep ... edited human stem cell lines and a growing suite ... the platform for these and future publicly available resources ...
(Date:4/4/2017)... NEW YORK , April 4, 2017   ... solutions, today announced that the United States Patent and ... The patent broadly covers the linking of an iris ... the same transaction) and represents the company,s 45 th ... our latest patent is very timely given the multi-modal ...
(Date:3/30/2017)... HONG KONG , March 30, 2017 ... developed a system for three-dimensional (3D) fingerprint identification by adopting ground ... technology into a new realm of speed and accuracy for use ... applications at an affordable cost. ... ...
Breaking Biology News(10 mins):
(Date:10/9/2017)... Charlotte, N.C. (PRWEB) , ... October 09, 2017 , ... ... Purple announced Dr. Christopher Stubbs, a professor in Harvard University’s Departments of Physics and ... Dr. Stubbs was a member of the winning team for the 2015 Breakthrough Prize ...
(Date:10/7/2017)... ... October 06, 2017 , ... ... and applications consulting for microscopy and surface analysis, Nanoscience Instruments is now ... Analytical offers a broad range of contract analysis services for advanced applications. ...
(Date:10/6/2017)... , ... October 06, 2017 , ... ... within the healthcare and technology sector at their fourth annual Conference where founders, ... 30 inspiring speakers and the ELEVATE pitch competition showcasing early stage digital health ...
(Date:10/5/2017)... ... 05, 2017 , ... Understanding the microbiome, the millions of bacteria that live ... You Are My Future, the newest exhibit on display at the University City Science ... condition through the lens of the gut microbiome. , Gut Love opens October ...
Breaking Biology Technology: