Quantcast
Environmental News for a Healthier Planet and Life

Help Support EcoWatch

World's Largest River Floods Five Times More Often Than It Used to

Climate
Flooded suburb of the city of Itacoatiara (Central Amazon region) in 2009. Jochen Schöngart, National Institute for Amazon Research

Extreme floods have become more frequent in the Amazon Basin in just the last two to three decades, according to a new study.

After analyzing 113 years of Amazon River levels in Port of Manaus, Brazil, researchers found that severe floods happened roughly every 20 years in the first part of the 20th century. Now, extreme flooding of the world's largest river occurs every four years on average—or about five times more frequently than it used to.


"With a few minor exceptions, there have been extreme floods in the Amazon basin every year from 2009 to 2015," study lead author, Jonathan Barichivich, environmental scientist at the Universidad Austral de Chile, said in a press release.

This increase in flooding could be disastrous for communities in Brazil, Peru and other Amazonian nations, the researchers pointed out.

"There are catastrophic effects on the lives of the people as the drinking water gets flooded, and the houses get completely destroyed," Barichivich told the Thomson Reuters Foundation.

The study, published Wednesday in the journal Science Advances, also determined that droughts in the Amazon Basin have increased in frequency.

"Our findings unravel the ultimate causes of the recent intensification—wet season getting wetter, and dry season getting drier—of the water cycle of the largest hydrological basin of the planet," Barichivich told Retuers.

The researchers linked the increase in flooding to a strengthening of the Walker circulation, which is induced by the contrast of warm Atlantic waters and the cooler waters of the Pacific.

Flooded area in the center of Manaus in 2009Jochen Schöngart, National Institute for Amazon Research

This ocean-powered air circulation system, which influences weather patterns and rainfall in the tropics and elsewhere, can partly be attributed to shifts in wind belts caused by climate change, as Reuters noted about the study.

"This dramatic increase in floods is caused by changes in the surrounding seas, particularly the Pacific and Atlantic oceans and how they interact. Due to a strong warming of the Atlantic Ocean and cooling of the Pacific over the same period, we see changes in the so-called Walker circulation, which affects Amazon precipitation," study co-author Manuel Gloor, from Britain's University of Leeds, said in the press release. "The effect is more or less the opposite of what happens during an El Niño event. Instead of causing drought, it results in more convection and heavy rainfall in the central and northern parts of the Amazon basin."

With temperatures in the Atlantic expected to continue warming, the scientists expect to see more of these high water levels in the Amazon River.

"We think that it's going to continue for at least a decade," Barichivich told Reuters.

Inundated house along Solimões River (Central Amazonia) during the record-breaking flood in 2012Jochen Schöngart / National Institute for Amazon Research

EcoWatch Daily Newsletter

These seven cookbooks by Black chefs have inspired the author's family. LightFieldStudios / Getty Images

By Zahida Sherman

Cooking has always intimidated me. As a child, I would anxiously peer into the kitchen as my mother prepared Christmas dinner for our family.

Read More Show Less
Hand sanitizer is offered to students during summer school sessions at Happy Day School in Monterey Park, California on July 9, 2020. FREDERIC J. BROWN / AFP via Getty Images

The Food and Drug Administration (FDA) has expanded its list of potentially toxic hand sanitizers to avoid because they could be contaminated with methanol.

Read More Show Less
Over the next couple of weeks, crews will fully remove the 125-foot-wide, 25-foot-tall dam, allowing the Middle Fork Nooksack to run free for the first time in 60 years. Ctyonahl / Wikimedia Commons / CC by 3.0

By Tara Lohan

The conclusion to decades of work to remove a dam on the Middle Fork Nooksack River east of Bellingham, Washington began with a bang yesterday as crews breached the dam with a carefully planned detonation. This explosive denouement is also a beginning.

Read More Show Less
A man observes a flooded stretch of Dock Street in Annapolis, Maryland on Jan. 25, 2010. Matt Rath / Chesapeake Bay Program

The National Oceanic and Atmospheric Administration (NOAA) said Tuesday that a trend of increased coastal flooding will continue to worsen as the climate crisis escalates.

Read More Show Less
A new tool called The Food Systems Dashboard aims to save decision makers time and energy by painting a complete picture of a country's food system. Photo courtesy of Dr. Jessica Fanzo and Dr. Rebecca McLaren

By Katie Howell

A new tool called The Food Systems Dashboard aims to save decision makers time and energy by painting a complete picture of a country's food system. Created by the Johns Hopkins' Alliance for a Healthier World, the Global Alliance for Improved Nutrition (GAIN), and the U.N. Food and Agriculture Organization (FAO), the Dashboard compiles food systems data from over 35 sources and offers it as a public good.

Read More Show Less
White's seahorse, also called the Sydney seahorse, is native to the Pacific waters off Australia's east coast. Sylke Rohrlach / Wikimedia Commons / CC by 2.0

By Manuela Callari

It can grow to a maximum of six inches (16 centimeters), change color depending on mood and habitat, and, like all seahorses, the White's seahorse male gestates its young. But this tiny snouted fish is under threat.

Read More Show Less

Trending

Democratic Presidential candidate Joe Biden speaks at a "Build Back Better" Clean Energy event on July 14, 2020 at the Chase Center in Wilmington, Delaware. Joe Biden / Facebook

Presidential hopeful Joe Biden announced a $2 trillion plan Tuesday to boost American investment in clean energy and infrastructure.

Read More Show Less