The U.S. Environmental Protection Agency's (EPA's) Office of Research and Development (ORD) is seeking partnerships in land-use change modeling in order to project ecological vulnerability at fine spatial scales. We are focusing exploratory research and testing existing techniques in the mid-Atlantic region because of the availability of spatially and temporally extensive ecological monitoring data, and because of numerous interagency environmental assessment projects ongoing the same region. Our initiative addresses the question, "Where will projected land-use change most threaten ecological resources in the mid-Atlantic region?"
Our priorities for vulnerability assessment include ecological resources directly displaced by land-use conversion, and those indirectly impacted by increased quantity and toxicity of runoff and air pollution. Because of our need to associate land-use change with likely ecological effects, we require spatially-explicit projections with resolutions in the neighborhood of 100m or higher. Temporally, we would like to project to the years 2010, 2030, and 2050, with known levels of uncertainty.
The mid-Atlantic study region is comprised of all or parts of ten eastern U.S. states, and includes the entire Chesapeake Bay watershed as well as those for the Delaware River and the Albemare-Pamlico Sound. Land-use conversion is one, if not the, primary stressor for ecological systems across this vast area. However, our reviews to date of land-use modeling techniques have led us to believe that meaningful projections require an intimate familiarity with the features and patterns of small places-- several counties at best. Therefore, we are planning to approach this initiative in two stages--a coarse regional overview, and an intensive study of selected subregions that we then infer to be most ecologically vulnerable.
Stage One
The coarse regional overview would utilize county-level data on
natural resource markets, land values, demographic patterns,
and
other socioeconomic variables to project land-use in 2010, by
county, for forest, pasture, row crops, and developed land.
Alternative projections would derive from models under
development by USDA and university resource economists. By
overlaying ecological resources of greatest frailty or concern
(wetlands, large blocks of contiguous forest, steep slopes,
etc.), we would identify subregions that appear to be at the
greatest risk ecologically for the year 2010. Selecting
subregions for more intensive study will also require
evaluating
which areas would be best served by ecological risk
assessment.
Areas amenable to the prevention or mitigation of ecological
degradation will be favored over those where remedial efforts
seem less plausible.
Stage Two
In selected subregions, we would explore additional county,
sub-
county, and spatially-explicit status and trends for issues
including local environmental resources, employment centers,
zoning, and infrastructure, to understand the forces that
affect
township and individual landowner decisions. Subregional
projections would be based on the estimated economic decisions
of
private landowners as well as on the likely continuation of
trends in infrastructure expansion. Efforts will also be made
to
incorporate major driving forces into the models that are
beyond
subregional boundaries. These forces would largely include
natural resource issues such as global markets, new production
technology, and national policy. Subregional projections to
2010, 2030, and 2050 would include alternative scenarios
derived
from varying our assumptions about local and external forces.
We plan to test several modeling techniques currently under
development in regional universities for single watersheds and
single- and several-county areas. We may find that certain
models are most applicable to subregions dominated by
particular
economies such as agriculture or mining, or by high rates of
residential conversion. In this event, we may apply multiple
models in the region in order to project watersheds or habitats
of greatest ecological vulnerability to land-use change.
We are very much interested in the land-use change initiative
of
the USGS EROS Data Center and the National Center for
Geographic
Information Analysis because of the ongoing project in the
Washington-Baltimore area, and the possibility in the future of
modeling large regions at high resolution. We are eager to
learn
from the expertise of these organizations, and hope to become
partners in the exploratory research.
This statement describes the preliminary status of a joint
land-use modeling initiative between ORD's National Exposure
Research
Laboratory and its National Health and Environmental Effects
Research Laboratory. For more information, please contact
Sandra
Bird at (706) 355-8124 or bird.sandra@epamail.epa.gov; or
Laura
Jackson at (919) 541-3088 or jackson.laura@epamail.epa.gov.