ForumGetting the Lowdown From High Up
|| ARS has an exceptionally broad program in
remote sensing that involves more than 20 laboratories around the country,
often in cooperation with other agencies in this country and abroad.
Most of the research takes advantage of remote sensing's ability to view entire
regions to monitor, assess, and manage farmland, rangeland, and
forestsincluding effects on the nation's waters.
The story that begins on page 4 highlights the work of the ARS Hydrology and
Remote Sensing Laboratory, in Beltsville, Maryland, working with the National
Aeronautics and Space Administration and other agencies. This includes aerial
and satellite monitoring of soil moisture as part of the global water cycle and
in relationship to global warming, tillage techniques, and pest infestations.
It also includes predictions of such things as flooding, drought, crop yields,
and soil carbon storage.
Similar work is done by other ARS labs throughout the country. Much of the
research is directed at watershedsareas drained by streamsbecause
they have a major effect on ecosystems. Groups of watersheds drain into basins
that in turn drain into large bodies of water.
From studies of one watershed in El Reno, Oklahoma, ARS hydrology engineer
Jurgen D. Garbrecht has developed computer software that uses digital landscape
technology to solve environmental problems. Garbrecht worked with Canada's
University of Saskatchewan in developing TOPAZ. Short for topographic
parameterization of the landscape, TOPAZ is a computer-based evaluation tool
that defines and analyzes land-surface characteristics, watershed
configurations, and drainage features.
TOPAZ has already gone global. Researchers, engineers, and educators in Europe
and the Middle East are using it. USDA is using it to generate drainage path
information for water quality models. Canadian researchers use it in their
Global Energy and Water Cycle Experiment, a study of the Mackenzie River Basin,
to better understand the role of cold regions in the global climate system.
TOPAZ creates data files from which images can be generated by most commercial
geographic information system packages. Scientists are now working with
colleagues in Tucson, Arizona, to add new features to TOPAZ for use in
combination with another ARS model that predicts runoff and erosion.
While protection of water quality at the watershed scale is an important part
of ARS' remote-sensing work, there are many other aspects of managing lands at
the watershed, basin, regional, or local level. For example, biologist Norman
C. Elliott and entomologist S. Dean Kindler in Stillwater, Oklahoma, are
cooperating with researchers at Oklahoma State (OSU) and Texas A&M
Universities to quickly, accurately, and cheaply map greenbug infestations on
wheat fields over entire regions. Greenbugs are a serious pest of grain and
sorghum in the Southern Plains. During severe outbreaks, wheat farmers lose
more than $250 million a year.
So far, the Stillwater team has done some field and greenhouse work with the
same sensors used on satellites. They can detect the unique light reflectance
characteristics of greenbug-damaged fields.
As part of a cooperative research and development agreement, Elliott is also
working with OSU and Site Specific Technology Development Group, Inc., to
develop a computer model to give farmers and consultants advice on controlling
greenbugs in wheat.
And precision agriculture would have no future without remote-sensing research.
ARS scientists across the country contribute to development of sensors and
techniques. Precision agriculture began with use of global positioning system
sensors to give farmers a square-foot-by-square-foot accounting of crop yields.
ARS scientists are expanding remote sensing to include live monitoring of such
things as crop growth, soil conditions, and plant water and fertilizer
needsÑdown to each square foot of land, over entire regions. This type
of work is being done from Beltsville to Phoenix, Arizona, to Weslaco, Texas.
Whether for precision farming or environmental monitoring, remote sensing is
done from 220 miles in space down to ground and water levels and below.
For example, researchers in New Orleans designed a submersible sensor to
monitor harmful algal species, such as those responsible for red tide and dead
zones. They are testing a prototype in the St. John's River in collaboration
with regional, state, and federal researchers.
The New Orleans research epitomizes the depth and breadth of ARS'
remote-sensing workusing the eyes of sensors at many different altitudes
to monitor the health of the Earth's farmland, rangeland, forest lands, and
bodies of water.
Jean L. Steiner
Acting ARS National Program Leader
Watershed Management and Remote Sensing
"Forum" was published in the
issue of Agricultural Research magazine.