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Sunday, November 29, 2015

New NASA GRACE study shows Brazil’s drought deeper than thought – Southeast losing 56 trillion liters of water in each of the past three years

GRACE water storage anomaly data over Brazil for 2002-2014. Red and orange are areas with water losses; blues are gains. Graphic: Getirana, 2015 / NASA Goddard Media Studios / Journal of Hydrometeorology
by Chris Arsenault, 30 October 2015
TORONTO (Thomson Reuters Foundation) - New satellite data shows Brazil's drought is worse than previously thought, with the southeast losing 56 trillion liters of water in each of the past three years - more than enough to fill Lake Tahoe, a NASA scientist said on Friday.
The country's most severe drought in 35 years has also caused the Brazil's larger and less-populated northeast to lose 49 trillion liters of water each year over three years compared with normal levels, said NASA hydrologist Augusto Getirana.
Brazilians are well aware of the drought due to water rationing, power blackouts and empty reservoirs in parts of the country but this is the first study to document exactly how much water has disappeared from aquifers and reservoirs, Getirana said.
"It is much larger than I imagined," Getirana told the Thomson Reuters Foundation. "With climate change, this is going to happen more and more often."
The Cantareira water reservoir system providing water for 8.8 million residents of Sao Paulo, Brazil's largest city, for example, was filled to less than 11% of its capacity last year, local officials reported.
Getirana's research, published this week in the Journal of Hydrometeorology, relies on 13 years of data from NASA's Gravity Recovery and Climate Experiment (GRACE) satellites which circle the earth detecting changes in the gravity field caused by movements of water on the planet. [more]

28 October 2015 (NASA Goddard) – Empty water reservoirs, severe water rationing, and electrical blackouts are the new status quo in major cities across southeastern Brazil, where the worst drought in 35 years has desiccated the region. A new NASA study estimates that the region has lost an average of 15 trillion gallons of water per year from 2012 to 2015. Eastern Brazil as a whole has lost on average 28 trillion gallons of water per year over the same time period.
Augusto Getirana, a hydrologist at NASA's Goddard Space Flight Center, in Greenbelt, Maryland, analyzed the amount of water stored in aquifers and rivers across Brazil from 2002 to 2015, interested in understanding the depth of the current drought.
A new data visualization of 13 years of GRACE data shows the distribution of water across Brazil. Blues indicate increases in water, mostly occurring in the western regions of Brazil in the rainforest. Meanwhile red and orange shows where water stores have declined, occurring mainly in the north and southeast. At the beginning of the data collection, in 2002, Brazil was just coming out of a drought that began in 2000. A wet period followed until 2012 when dry conditions set in again due to a lack of precipitation and higher than usual temperatures, according to supplemental data.
Southeastern Brazil was hardest hit by drought conditions, said Getirana. To make matters worse, Brazil relies on rivers that feed into reservoirs and dams that generate about 75% of the electrical power for the country. By September 2014, for example, the Cantareira reservoir system that provides water for 8.8 million people in São Paulo's metro region reported that it was filled to 10.7% of its total capacity, a situation that has led to major water rationing.
Research: Extreme water deficit in Brazil detected from space.
Journal: Hydrometeorology, 27 October 2015.
Link to paper: Extreme water deficit in Brazil detected from space
Here is the YouTube video.
Additional footage from: Itaipu Binacional Files. 

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