According to NASA-funded researchers, developed land in
the greater Washington-Baltimore metropolitan area is
projected to increase 80 percent by 2030. Scientists used a
computer-based decision support model loaded with NASA and
commercial satellite images to simulate three policies
affecting land use.
The researchers, Claire Jantz and Scott Goetz, from the
University of Maryland, College Park, Md., and the Woods
Hole Research Center, Woods Hole, Mass., also found a 39
percent increase in developed land in the region from 1986
to 2000. Some of the most striking changes occurred around
the Dulles Airport area in Northern Virginia.
Observations from NASA and commercial Earth observation
satellites were used in a United States Geological Survey
(USGS) computer model, called SLEUTH. The model was applied
to 23,700 square kilometers (9151 sq. miles) of the
Washington-Baltimore metropolitan area. The initial aim was
to simulate the impact of future policy scenarios on the
area and Chesapeake Bay watershed. “The satellite
observations provided us with an unprecedented ability to
monitor the urbanization process and capture the patterns of
urban sprawl,” Goetz said.
The study is in the March issue of Environment and Planning
B. It explains how models may be used to forecast the
effects of urban growth and runoff on the Chesapeake Bay
estuary system.
The study showed how high resolution commercial imagery from
Space Imaging’s IKONOS satellite can be used to complement
NASA’s imagery from Landsat satellites. IKONOS images, with
resolutions up to one meter (3.28 feet), were used with
county-level air photos to link to 30-meter Landsat
observations, which cover vast areas and offer a longer time
frame for assessing urban change.
The project was designed to study declining water quality in
the Chesapeake Bay estuary due in part to disruptions in the
hydrological system caused by urban and suburban
development. The goal was to create a modeling system that
could assess future development and support decision making
by exploring the potential impact of different regional
management scenarios. Future growth was projected out to
2030 using three different policy scenarios. The scenarios
were based on current trends, managed, and ecologically
sustainable growth.
The current trends scenario simulated how the Washington
metropolitan area might change if development policies
remained the same. This scenario included forest and
agricultural preservation already in place, leaving
unprotected areas open for development. In this scenario,
development increased by 80 percent by 2030.
The managed growth scenario assumed added protection of
forests and agriculture areas and placed moderate growth
boundaries around already built areas. In this scenario,
development increased by 30 percent by 2030. In the
ecological scenario, strong protection of most forests and
agricultural areas was projected, so development only
increased by 20 percent by 2030.
“The model is a tool that can be used for land use planning
and resource management,” Jantz said. “It offers the ability
to explore and visualize alternative futures.”
The model is applicable to land use studies, and it has
small to large-scale potential. It can also help decision-
makers assess the configuration of landscapes in forests and
urban areas, and understand sources of runoff related to
water quality in streams. The Maryland Department of Natural
Resources is exploring use of the model to target forest
resources, restoration and conservation activities.
NASA’s Earth Science Enterprise is dedicated to
understanding the Earth as an integrated system and applying
Earth System Science to improve prediction of climate,
weather, and natural hazards using the unique vantage point
of space. NASA funded the study, with additional funds from
the Chesapeake Bay Foundation.
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