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Integration of Spatial Data: Evaluation of Methods Based on Data Issues and Assessment Questions

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Abstract:EPA's Regional Vulnerability Assessment (ReVA) Program has focused initially on the synthesis of existing data. We have used the same set of spatial data and synthesized these data using a total of 11 existing and newly developed integration methods. These methods were evaluated in terms of 1) how well each individual method performs given different data issues that are encountered with existing data, and 2) how effectively each method addresses different types of assessment questions.

Specific data issues that are addressed in our evaluation of integration methods include:

Discontinuity -How are the methods affected by variables that (in raw form) are counts, such as number of aquatic species, versus having only continuous data?

Imbalance -What effect does having too many variables of a particular type ( e.g. representative of terrestrial conditions versus aquatic) have on the integration results from individual methods?

Skewness -What effect does having variables with highly skewed distributions have on integration results? Many statistical methods are valid only for symmetrically distributed data or require transformation of the data.
Interdependency -How are the methods affected by including variables that are highly correlated with one another?

Prioritization of risk management actions involves balancing many different factors that can be addressed through a series of assessment questions. ReVA's evaluation of integration methods considers which methods are most suitable to address questions such as:

What is the overall environmental condition of the region?
What is the relative condition of locations within a region?
Where are the most vulnerable (i.e. both high stressor levels and high numbers of resources) locations in a region?
How will conditions and vulnerabilities change in the future?
How applicable are risk management options to other locations in the region?
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Citation:Smith, E. R., L. T. Tran, and R. V. O'neill. Integration of Spatial Data: Evaluation of Methods Based on Data Issues and Assessment Questions. Presented at US EPA 23rd Annual National Conference on Managing Environmental Quality Systems, Tampa, FL, April 13-16, 2004.
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Contact: Chris Siebert - (702) 798-2234 or siebert.christopher@epa.gov
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Division: Environmental Sciences Division
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Branch: Landscape Characterization Branch (RTP)
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Product Type: Abstrct/Oral
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Presented: 04/13/2004
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Related Entries:
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Bullet Item Regional Scale Comparative Risk Assessment
spacer Relationship Reason:   A Project of the Product
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Last Updated on Monday, October 22, 2007
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