News / Science & Technology

Detailed Forest Change Mapped

Using Landsat imagery and cloud computing, researchers mapped forest cover worldwide as well as forest loss and gain.
Using Landsat imagery and cloud computing, researchers mapped forest cover worldwide as well as forest loss and gain.

Related Articles

Global Warming Gases at Highest Level Ever

World Meteorological Organization says accelerating trend will have devastating consequences, unless nations do more to to rein in emissions

Demand for Palm Oil Fuels Land Conflicts in Africa, Southeast Asia

New report focuses on human rights violations in the palm oil industry

Illegal Logging Threatens South Sudan Forests

Locals who cut down trees in Eastern Equatoria's forest reserves insist they have no other way to make a living.
VOA News
The world lost 2.3 million square kilometers of forest between 2000 and 2012 and gained 800,000 square kilometers according to a new study. The loss is more than 8 times the size of Texas, the biggest state in the continental U.S.

Deforestation, wildfires, windstorms and insects are all reasons for the decline as reported in a new study based on data from the NASA-U.S. Geological Survey Landsat 7 satellite. The researchers analyzed 143 billion pixels in 654,000 Landsat images to compile maps of forest loss and gain between 2000 and 2012.

The study was done by scientists from the University of Maryland, Google, the State University of New York, Woods Hole Research Center, the U.S. Geological Survey (USGS) and South Dakota State University.

During the study period, Brazil cut its deforestation rate from approximately 40,000 square kilometers per year to approximately 20,000 square kilometers per year.

"That's the result of a concerted policy effort to reduce deforestation, and it sets a standard for the rest of the world," said Matthew Hansen, whose team at the University of Maryland in College Park, Md., led the new study.

The team found that the deforestation rate in other countries increased.  Indonesia's deforestation rate doubled in the study period, from approximately 10,000 square kilometers per year in 2000-2003 to more than 20,000 square kilometers in 2011-2012.

Prior to this study, country-to-country comparisons of forestry data were not possible at this level of accuracy. Different countries define forests differently, making previous global comparisons difficult with existing inventories.

"When you put together datasets that employ different methods and definitions, it's hard to synthesize," Hansen said. "But with Landsat, as a polar-orbiting instrument that takes the same quality pictures everywhere, we can apply the same algorithm to forests in the Amazon, in the Congo, in Indonesia, and so on. It's a huge improvement in our global monitoring capabilities."

The maps also illustrate the impact of politics on land cover. On the island of Borneo, the maps clearly show the border between Malaysia and Indonesia. Malaysia's heavy logging along forest roads is visible right up to the Indonesian border, where forests were still largely intact as of 2012. In Côte d'Ivoire, a civil war in 2002 corresponded with intense deforestation of several previously protected nature reserves.

A different pattern of change appears in the southeastern U.S., where landowners harvest trees for timber and quickly plant their replacements.

"Of this eco-region in the southeast, 30 percent of the forest land was regrown or lost during this period," Hansen said. "It's incredibly intensive. Trees are really treated like a crop in this region."

In the U.S. state of Alabama, Landsat also detected miles-long streaks of destroyed forest. When the researchers examined the year-by-year record, they found the damage occurred in 2011 after a violent tornado season.

The results of the study will be published in the Nov. 15 issue of the journal Science.

You can have a look at the map details using this interactive tool.

Here's a video about the study:

You May Like

Could Nemtsov Threaten Putin in Death as in Life?

Dynamic and debonair opposition leader had supported liberal economic reforms, criticized Russian president's aggression in Ukraine More

Oil Smuggling Highlights Challenges in Shutting Down IS Finances

Pentagon spokesman says Islamic State 'certainly continues to get revenue from the oil industry black market' but that airstrikes have made a dent More

India Focuses on Infrastructure, Investment to Propel Economy

Government expects economy to grow at 8 to 8.5 percent in next fiscal year More

This forum has been closed.
Comment Sorting
Comments
     
by: Shinoda Marikoh from: HKT
November 16, 2013 6:27 PM
Of course they consider the difference of north and south, and of course they understand we have for seasons.

Of course they take these things take into account and made these maps.
They are scientists, not stupid journalists.

by: Yoshi from: Sapporo
November 15, 2013 9:34 PM
What a good job ! I agree this product is not only consistent grobaly but relevant locally. I looked into my resident region and found some informations compatible with urban exploitation.

I have some questions concerning how these forest data are acquisited. First, how the date of the southern and northern hemisphere are shown in one map? I guess green season is different between the two. Second, how the data of greenery of leaf falling trees is handled? Does this map deal only evergreen trees?

by: Kitagawa Keikoh from: Daikanyama, TKO
November 15, 2013 6:29 PM
It's amazing data visualization. We can understand easily where loss forest.

Please look at "Ishima" in Japan, located near Hiroshima known as the atomic bomb in WWII. This hole island is totaly red because they had lost almost all forest due to wildfire in 2011.

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
US Supreme Court Hears Hijab Discrimination Casei
X
Katherine Gypson
February 25, 2015 11:30 PM
The U.S. Supreme Court has heard opening arguments in a workplace religious discrimination case that examines whether a clothing store can refuse to hire a young woman for wearing the headscarf she says is a symbol of her Muslim faith. Katherine Gypson reports from the Supreme Court.
Video

Video US Supreme Court Hears Hijab Discrimination Case

The U.S. Supreme Court has heard opening arguments in a workplace religious discrimination case that examines whether a clothing store can refuse to hire a young woman for wearing the headscarf she says is a symbol of her Muslim faith. Katherine Gypson reports from the Supreme Court.
Video

Video Falling Gas Prices Hurt Nascent Illinois Hydraulic Fracturing Industry

Falling oil prices are helping consumers purchase cheaper petroleum at the pump. But that’s made hydraulic fracturing or “fracking” less economically viable for the companies in the United States invested in the process. VOA’s Kane Farabaugh reports on one Midwestern town that was hoping to change its fortunes by cashing in on the next big U.S. oil boom.
Video

Video Fighting in Sudan's South Kordofan Fuels Mass Displacement

Heavy fighting in Sudan's South Kordofan state is causing hundreds of thousands to flee into uncertain conditions. Local aid organizations estimate as many as 400,000 civilians have been internally displaced since the conflict began more than three years ago, while another 250,000 have fled across the border to refugee camps in South Sudan. VOA's Adam Bailes reports.
Video

Video Lao Dam Project Runs Into Opposition

A Lao dam project on a section of the Mekong River is drawing opposition from local fishermen, international environmental groups and neighboring countries. VOA's Say Mony visited the region to investigate the concerns. Colin Lovett narrates.
Video

Video A Filmmaker Discovers Her Biracial Identity in "Little White Lie

Lacey Schwartz grew up in an upper middle-class Jewish family, in a town in upstate New York where almost everyone she knew was white. She assumed that she was, as well. Her recent documentary, Little White Lie, tells the story of how she uncovered the secret of her true racial background. VOA’s Carolyn Weaver has more on the film.
Video

Video Deep Under Antarctic Ice Sheet, Life!

With the end of summer in the Southern hemisphere, the Antarctic research season is over. Scientists from Northern Illinois University are back in their laboratory after a 3-month expedition on the Ross Ice Shelf, the world’s largest floating ice sheet. As VOA’s Rosanne Skirble reports, they hope to find clues to explain the dynamics of the rapidly melting ice and its impact on sea level rise.
Video

Video US-Cuba Normalization Talks Resume Friday

Negotiations aimed at normalizing diplomatic relations between the U.S. and Cuba resume Friday. On the table: lifting a half-century trade embargo and easing banking and travel restrictions. There's opposition in Congress, but some analysts say there may be sufficient political and economic incentives in both nations for a potential breakthrough this year. VOA's Mil Arcega reports.
Video

Video Pakistan's Deadline For SIM Registration Has Cellphone Users Scrambling

Pakistani cell phone users have until midnight Thursday to register their SIM cards, or their service will be cut off. While some privacy experts worry about government intrusion, many Pakistanis are just worried about keeping their phone lines open. VOA Deewa reporter Arshad Muhmand has more from Peshawar.
Video

Video Myanmar Warns Factory Workers to End Strikes

Outside Myanmar's main city Yangon, thousands of workers walked off their jobs earlier this month demanding a doubling of their wages, pay raises after a year and input from labor unions on industrial regulations. Since Friday, the standoff has grown more tense as police moved in to disrupt the sit-ins, resulting in clashes that injured people from both sides. VOA correspondent Steve Herman visited industrial zones which have become a focus of Myanmar's fledgling workers rights movement.
Video

Video Oscar Winners Do More Than Thank the Academy

The Academy Awards presentation is Hollywood’s night to reward the best movies from the previous year. It’s typically a lot of glitter, a lot of thank you’s, a lot of speeches. But many of this year’s speeches carried messages beyond the thank you's. VOA’s Carolyn Presutti takes a look.

All About America

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More