Featured Research

from universities, journals, and other organizations

NASA Index Uses Plants To Shed New Light On Droughts

Date:
September 1, 2000
Source:
NASA/Goddard Space Flight Center
Summary:
NASA has a new tool designed to keep a close watch over our plants. What we see in the reflection of the vegetation may help researchers do a better job of monitoring and, one day, predicting periods of drought.

NASA has a new tool designed to keep a close watch over our plants. What we see in the reflection of the vegetation may help researchers do a better job of monitoring and, one day, predicting periods of drought.

Related Articles


A new Multi-spectral Drought Index measures the impacts of too little water or too much rainfall on vegetation. The index will also be used to verify other existing drought-monitoring products.

"What makes this data set unique is its unprecedented detail, which provides a resolution four times that of current drought prediction maps, and it is based on a 20-year data record," said Compton Tucker, the research scientist leading the project at NASA's Goddard Space Flight Center, Greenbelt, MD.

The new Multi-spectral Drought Index utilizes and improves the data from the Normalized Difference Vegetation Index (NDVI) and shows deviations from average vegetation levels. The NDVI is an index created by Tucker 20 years ago to measure the absorption and reflectance of sunlight by plants.

The NDVI data sets show the greening and browning of plants as they relate to seasonal changes and conditions such as drought or abundant rainfall. The data is gathered by the polar-orbiting satellites built by NASA and operated by the National Oceanic and Atmospheric Administration.

The satellites measure the reflectance and absorption characteristics of plants at different wavelengths in the electromagnetic spectrum. The data are registered in numerical form, and translated by researchers into monthly maps of vegetation color changes, which in turn indicate how much soil moisture is available to plants. Since the global data set spans a 20-year time period, researchers can better determine what are "normal" levels of plant growth, and what are unusually high or low levels.

Sunlight can either be absorbed by leaves and needles or scattered within and among them. By using red and infrared wavelengths in the spectrum, multi-spectral imaging measures the absorption rate of sunlight and identifies levels of chlorophyll generated in vegetation. When more sunlight is absorbed, higher levels of chlorophyll are generated in vegetation showing plant growth. Conversely, when a plant is stressed from lack of fertilizer or water, it will limit its chlorophyll production compared to healthy plants.

"The new Multi-spectral Drought Index is used to generate better vegetation anomaly maps than before," according to Tucker. Light brown on the drought map means there's diminished plant growth, green on the map indicates a higher than average plant growth.

A map generated for July 2000 indicated a drought in the western United States. "The data clearly shows why we're having wildfires," Tucker said. "Soil conditions are dry, and the diminished vitality of vegetation indicates that."

Many drought products are based on water availability in soils. The new index maps integrate climate variables such as soil moisture, temperature and precipitation, and show how vegetation responds to environmental conditions around the world.

"The bottom line is that the new Multi-spectral Drought Index reflects the actual environmental conditions of the vegetation, and at a much higher resolution than previously available, which will be helpful in supplementing and validating the NOAA drought forecast maps," Tucker said.

The first data sets covering North America and Africa and are currently available at:

http://earthobservatory.nasa.gov/Drought

Images and animations are available at: http://svs.gsfc.nasa.gov/imagewall/drought.html

Complete data sets including images from all continents are expected to be released to the scientific community early next year. This research is done in support of NASA's Earth Science Enterprise, Washington DC. The Enterprise is dedicated to the long-term study of how human-induced and natural changes affect our global environment. More information about the Enterprise can be found at: http://www.earth.nasa.gov


Story Source:

The above story is based on materials provided by NASA/Goddard Space Flight Center. Note: Materials may be edited for content and length.


Cite This Page:

NASA/Goddard Space Flight Center. "NASA Index Uses Plants To Shed New Light On Droughts." ScienceDaily. ScienceDaily, 1 September 2000. <www.sciencedaily.com/releases/2000/09/000901075643.htm>.
NASA/Goddard Space Flight Center. (2000, September 1). NASA Index Uses Plants To Shed New Light On Droughts. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2000/09/000901075643.htm
NASA/Goddard Space Flight Center. "NASA Index Uses Plants To Shed New Light On Droughts." ScienceDaily. www.sciencedaily.com/releases/2000/09/000901075643.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Christmas Kissing Good for Health

Christmas Kissing Good for Health

Reuters - Innovations Video Online (Dec. 22, 2014) Scientists in Amsterdam say couples transfer tens of millions of microbes when they kiss, encouraging healthy exposure to bacteria. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Brain-Dwelling Tapeworm Reveals Genetic Secrets

Brain-Dwelling Tapeworm Reveals Genetic Secrets

Reuters - Innovations Video Online (Dec. 22, 2014) Cambridge scientists have unravelled the genetic code of a rare tapeworm that lived inside a patient's brain for at least four year. Researchers hope it will present new opportunities to diagnose and treat this invasive parasite. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
New Fish Species Discovered, Setting Record for World's Deepest

New Fish Species Discovered, Setting Record for World's Deepest

Buzz60 (Dec. 22, 2014) A new species of fish is discovered living five miles beneath the ocean surface, making it the deepest living fish on earth. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins