Geographers at Clark University and Clark Labs in Worcester, Massachusetts, use geographic information system (GIS) and image processing computer software to produce images that help them understand the impact of humans on the Earth. A spring 2016 exhibit by J. Ronald Eastman, professor of geography and director of Clark Labs, highlights some of these images. The exhibit is sponsored by Clark University's Higgins School of Humanities and Clark Labs.

1. Mapping
our impact
on the Earth

2. How do geographers use computer
software to envision the future of our
planet?
What can they “see” via
geographic information system (GIS)
and image processing?

3. What
do
you
see?

4. GIS expert J. Ronald Eastman and his graduate students use a
software system that he developed at Clark Labs to produce
images that indicate possible future changes to the landscape.
The prior image depicts the vulnerability of cropland in
northwest Ohio to becoming developed. By combining
historical data with maps that show slope, elevation and the
proximity of current roads and urban development,
geographers can predict how likely it is that cropland might be
subsumed in the future.
‒ Analysis by Hannah Rush ’15, M.S. ’16, now research assistant with Clark Labs

5. What do you see?

6. Using Earth observation satellite images, maps and other
sources, geographers can create visual displays to gain insights
they might not otherwise “see” when perusing raw data.
The prior image shows the likelihood that mangrove swamps
in Nakhon Si Thammarat, Thailand, will be turned into ponds
to raise shrimp. The left panel shows areas of present-day
pond aquaculture (in light blue, 2014); the right panel, the
prediction for 2050. If you eat shrimp, it most likely was raised
in these ponds, which produce much of the world’s shrimp.
‒ Analysis by Sean Cunningham ’14, M.S. ’15, and J. Ronald Eastman, professor of geography and director of Clark Labs

7. What do you see?

8. Geographers can gain much insight by taking seemingly
unrelated, complex bits of information, entering that data into
computer software and producing a simple, elegant image.
When people move from one city to another, gypsy moths
travel with them. The prior image combines data on tree
species and climate; the rate at which people move from
infested areas across the U.S.; and satellite images of nighttime
lights, indicating changes in population. Taken as a whole, the
image shows the susceptibility of the landscape to attack by
gypsy moths.
‒ Analysis by Chris Lippitt ’05, M.A. ’06; James Toledano, M.A. ’91, Ph.D. ’97, now executive director, Clark Labs;
Florencia Sangermano, M.A. ’08, Ph.D. ’09, now visiting assistant professor at Clark/assistant research professor for Clark Labs

9. What do
you see?

10. Bobcats are very secretive, and it’s difficult for researchers to
rely on sightings to map where the predators live.
By inputting the data gathered from radio collars – which
indicate bobcats’ favorite habitat areas (in green), when and
where they travel, how close they get to humans and the type
of land they like to cross in central Massachusetts –
geographers can produce a color-coded map to help state
officials figure out where to build safe corridors between
habitat areas. Orange areas are riskier for the bobcats than
yellow ones; gray areas are unsafe.
– Analysis by J. Ronald Eastman, professor of geography and director of Clark Labs, and Megan Van Fossen, M.A. ’04

11. What do you see?

12. During El Niño, which occurs every two to seven years, the
central Pacific Ocean warms up in December and January.
The prior image shows how parts of the world experience
heavier precipitation (top panel), while others sustain drier
conditions (bottom panel). Red shows the peak of El Niño –
named for the Christ child – at the end of December.
Areas in blue show their strongest response (wet, top panel;
dry, bottom) six months before the El Niño peak; those in
yellow, six months after. Intermediate colors are spread
between those two extremes. The more saturated the colors,
the stronger the impact of El Niño.
– Analysis by Elia Machado, M.A. ’09, Ph.D. ’11

13. What do you see?

14. By incorporating the Normalized Difference Vegetation Index
data set, derived from images from Earth satellites,
geographers can understand the connections between climate
change and the photosynthesis — also called productivity —
of plants.
The prior image shows seasonal trends in photosynthesis in
parts of the United States and Canada from 1982 to 2010. By
mapping these trends, researchers can see that plants are
becoming increasingly productive throughout the year. This
higher productivity is consistent with warming temperatures,
increased carbon dioxide and other possible factors.
– Analysis by J. Ronald Eastman, professor of geography and director of Clark Labs, and
Florencia Sangermano, M.A.’08, Ph.D.’09, visiting assistant professor at Clark/assistant research professor for Clark Labs

15. What do you see?

16. Geographers attempt to understand the impact of humans on
the environment. But they also try to predict how nature
might affect humans.
Huge (10- to 500-kilometer) ocean eddies, whether warm or
cold, can influence everything from the productivity of
commercial fishing to installation of oil platforms. As a result,
scientists have begun to monitor eddies and predict future
movements. The prior image shows identified eddies on Oct.
14, 1992 (those in yellow and red have the highest amplitude).
– Analysis by Qingling Wu, Ph.D. ’13

17. What do you see?

18. Sometimes geographers “predict” as a way to fill in the gaps in
their knowledge.
The prior image combines data on the ranges of species –
from 30 species in some areas (lighter colors) to as many as
238 in others (dark green) – along with satellite images of
climate and vegetation. This allows researchers to picture the
rich diversity and range of mammals in the Amazon region of
South America.
– Analysis by J. Ronald Eastman, professor of geography and director of Clark Labs, and
Florencia Sangermano, M.A. ’08, Ph.D. ’09, visiting assistant professor at Clark/assistant research professor for Clark Labs

19. What
do
you
see?

20. Geographers often are surprised by the remarkable pictures
that result when they apply image-processing techniques to
better understand complicated data.
In the prior image, researchers used a technique called
“segmentation,” grouping together contiguous pixels, which
are the dots of color that make up a digital image. Thus, they
could provide structure to satellite images of fluids and other
amorphous substances – in this case, cloud cover over South
America in February 2000 – that otherwise would be too
challenging to model and “read.” The result? A work of art.
– Analysis by Florencia Sangermano, M.A. ’08, Ph.D. ’09, visiting assistant professor at Clark/assistant research professor for Clark Labs

21. Additional credits
The images and analyses in this slideshow are part of an exhibit by
J. Ronald Eastman, professor of geography at Clark University and
director of Clark Labs in Worcester, Massachusetts.
To produce these images, he and his graduate students used Clark
Labs’ TerrSet tools, including the IDRISI Geographic Information and
Image Processing System, the Land Change Modeler, the Habitat
and Biodiversity Modeler and the Earth Trends Modeler.
The spring 2016 exhibit, titled “geoEnvisioning,”
was sponsored by Clark’s Higgins School of Humanities
and Clark Labs.