&EPA
United States
Environmental
Protection Agency
Office of Research
and Development
Washington, DC 20460
EPAA620/R-01/004e
May 2002
EMAP-West Communications
Landscape Data - Its Use in Understanding Ecological Condition
Introduction
Landcover and land use data are fundamental ingredients of
ecological studies that deal with the impacts of human activities
over large regions. While these data are useful for many purposes,
the major focus of the Landscapes Team in EMAP-West will be to
evaluate the association of multiple landscape metrics with aquatic
condition that is being measured by the Surface Waters and
Coastal groups. Since the condition of estuaries and rivers and
streams is clearly influenced by large-scale processes, quantitative
evaluation of that influence is needed. It is the goal of the
Landscapes Team to assess spatial variability in landscape pattern
and the degree to which that pattern is associated with the condi-
tion of estuaries and inland surface waters. If conditions in aquatic
resources are closely linked to watershed-scale landscape patterns,
it may be possible to assess potential conditions of aquatic resour-
ces from landscape data at many scales across the western United
States. This could allow more informed targeting of waterbodies
for protection and/or restoration activities.
More than Maps
Because landscapes data are primarily derived from satellite
imagery, complete coverage of the 12 contiguous states of EMAP-
West is available (see the figure below showing the National Land
Cover Data for the West).
Advances in computer technology and geographic information
systems (GIS) have made it possible to calculate complex landscape
metrics that have uses far beyond the production of attractive maps.
While the information used to construct the map above is a formida-
ble data set in itself, it can be combined with other data to evaluate
complex interactions. For example, the impact of roads on aquatic
resources requires multiple data sets that must be overlaid and then
related to multiple water quality variables.
Progress
To date, emphasis has been placed on bringing a series of geograph-
ically based data sets together in a format that allows for the calcu-
lation of various metrics. An example of an indicator that is being
developed, potential grazing impact, is shown in the figure below.
w f;
Potential Grazing
Impact
• Low
I I Moderate
CH High
A core set of metrics is being developed for each state and
recorded to CD's for easy distribution. The State of Oregon and the
Southern Rockies region have CD's prepared which are under
review. States should find these CD's as a useful source readily
available landscapes data.
As the Program develops, the landscape indicators will be tested
and, if the expected relationships are found, predictive models of
aquatic condition will be developed. These models may ultimately
provide the states and tribes of the West with an important new
tool for tackling their monitoring and assessment challenges.
For further information, contact:
Daniel T. Heggem
Landscapes Lead
Heggem.Daniel@epa.gov
(702)798-2278
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