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ReVA Approach

Basic Information
Fall trees
Current science indicates that future environmental protection efforts must address problems that are just emerging or are on the horizon. Many of these problems are subtle and cumulative, with widespread, regional effects and poorly understood implications. The research approach advocated by ReVA differs from typical ecological research in that it seeks to integrate many different types of information from many different sources into a cohesive product.

Much of the last 100 years of ecological research has focused on examining the effects of single components of ecosystems one by one. For instance researching the causes of declines in populations of the Red-cockaded woodpecker or the Black-footed Ferret. Returning to the human health analogy, this is similar to a physician focusing on one nutrient in isolation to explain an ailment of a patient.

This approach works well when determining how a deficiency in vitamins or minerals may effect health such as a lack of iron contributing to anemia or a lack of iodine causing a goiter. However, this one-by-one approach is less useful to explain the root causes of chronic conditions such as coronary heart disease or diabetes where the severity of the health issue is influenced by diet, genetics, behavior, and socio-economic factors. Similarly, many of the issues facing the environment are chronic conditions such as the impairment of our nations waters being affected by point sources (discharge pipes such as municipal waste water treatment facilities), non-point sources (pollution generated by activities such as agriculture or urban areas), water usage, and climate.

ReVA uses four interacting functions to develop regional assessments that address current and future (projected) chronic environmental problems:

  1. Landscape: Data on stressors and effects from many sources must be placed into spatial context and synthesized using Geographic Information Systems (GIS) techniques.
  2. Research Gaps: Research must fill critical gaps in our ability to apply the data at landscape and regional scales, and to understand how socioeconomic factors affect environmental conditions.
  3. Real World: An assessment component must keep the project grounded in the “real world” by applying the data and risk assessment techniques to specific regions.
  4. Data and Analytical Tools: This final step is critical to assuring that the results of the research can be applied to continuing regional assessments. The data and analytical tools must be transferred into the hands of regional managers, ReVA accomplishes this final step by developing web based demonstration projects.


ReVA first determines the spatial distribution of sensitive ecosystems (receptors) by analyzing known distributions of plant and animal populations or communities within ecosystems. Modern methods in landscape ecology and characterization such as satellite based remote-sensing are used to further identify the locations of ecosystems that are vulnerable to future stress through topographic features, edaphic conditions, and habitat-patch configuration. Existing sensitivity and stress-response models of important ecological communities (developed by ORD ecosystems, protection research, and others) are used to quantify potential exposures and are tested for their ability to provide cause-effect information on a regional scale. Monitoring data collected at several spatial and temporal scales by other Federal or State agencies further refine estimates of exposure by providing information on current condition, known stressors, and stressor effects; issues of scale and the ability to extrapolate data regionally are evaluated carefully. Information on socioeconomic factors is integrated into the assessment to gain an understanding of which factors have contributed to current environmental conditions. This integration forms the conceptual basis for predicting future conditions and vulnerability.

Research Gaps

Past research has focused largely on single stressor-receptor relationships. Currently, little is known about cumulative and synergistic effects of multiple stressors. Similarly, most effects research has focused on small spatial scales primarily because it is rarely feasibile to do controlled experiments on a large scale. The applicability of small spatial-scale research to regional problems often is limited. New approaches, primarily in the areas of landscape ecology and characterization, are used to estimate vulnerability on a regional scale. This research currently includes ongoing efforts in metapopulation modeling, cumulative effects, economic geography, integrative indicators of ecosystem condition, scale issues, and landscape dynamics. Improved models of multiple-stressor exposures developed as part of the Multimedia Integrated Modeling System (MIMS) also can be incorporated as they become available. New research in the area of socioeconomic drivers and resource valuation is constituting a major focus within ReVA. Projections of future conditions are done by integrating socioeconomic models that predict changes in consumption of ecological goods and services with projected trends in ecosystem sensitivity.

Socioeconomic modeling is a key component to identifying the forces of environmental change: it will provide high-resolution growth profiles of emissions, infrastructure needs, and future land use, with associated changes in habitat fragmentation, vegetative cover, runoff, soil erosion, and wetland conversion. These profiles will be derived from models of regional resource economics, development desirability, planned development and population projections, plus high-resolution transportation models and employment growth models. Research into resource valuation is expected to refine predictions of environmental vulnerability by providing a means to communicate opportunity costs associated with alternative management decisions.

Real World

Concurrent with the development of an integrated approach to regional risk assessment, ReVA investigators are testing techniques for their applicability to real-world environmental issues. This approach supports EPA's new initiative of “Place-Based Studies” which seeks to present research themes in a spatial context – connecting research to people, ecosystem services and problems on the ground. This approach also supports EPA’s "Americans' Right to Know" and “Community-Based Environmental Protection” initiatives by improving access to comprehensive information and using continuous stakeholder input to develop the decision-support tools. As ReVA evolves, the integrated assessment approach also should provide feedback to ORD on the success of its research and development activities in terms of actual improvement in environmental quality, as stated in goals established for the Government Performance and Results Act (GPRA).

Data and Analytical Tools

The final function for ReVA will be technology transfer to the area of interest. The role of EPA’s Office of Research and Development is research and technology development, not continuing assessment. Thus, the ReVA clients/partners must be able to refine projected conditions as new information becomes available and as environmental management actions are implemented that may change future conditions. ReVA will have two basic arms. The first of these is research: we will develop, through focused effort, assessment technology integration techniques. The second arm functions as the application group: it works directly with the region to pose alternative "what if" questions, and demonstrates the use of the final decision-support tool. Depending on capabilities within the region, ReVA may provide analytical support by detailing part of the applications team to work within the Region until capabilities are developed sufficiently within the regional office. The goal in this case is to provide user support enabling the region to fully utilize ReVa tools while ORD scientists continue to explore new research questions as future issues emerge.


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