Uncertainty in the Design of the Measurement Frameworks Underlying GIS-Based Multipathway Risk Models. Z. Pekar, E. Brady-Roberts, T. K. Pierson, and D. Crawford-Brown; Research Triangle Institute, US Environmental Protection Agency, University of North Carolina at Chapel Hill
The use of geographic information system-based models (GISMs) in assessing multipathway risk (MPR) offers a powerful tool for supporting environmental decision making. GISMs, when integrated with demographic and land use data, can provide highly refined estimates of the distribution of risk within specific receptor populations. This enhanced resolution in characterizing risk allows decision makers to consider not only the magnitude of risk experienced by more highly exposed individuals within a given receptor population, but also the overall distribution of risk across modeled individuals within study areas. While GISMs have great potential in supporting decision making, significant uncertainty surrounds their design. Specifically, a wide variety of GISM formulations (i.e., measurement frameworks) can be used in modeling MPR scenarios, reflecting both the range of spatial data available for characterizing receptor location as well as the various ways in which these data can be used in predicting exposure. Despite the increased use of GISMs in supporting decision making, to-date there has been little research into the issue of uncertainty surrounding the design of these models. To address this issue, we developed three GIS-based MPR models representing a range of potential model formulations and measurement scales. Each of the three models was then used to evaluate residential and beef farmer risk for five case study hazardous waste combustion facilities. The results generated from each of these models were then compared to determine whether they were: (a) statistically different from each other; and (b) likely to produce different risk-based decisions. The results suggest that, depending on the pattern of demographics and land use surrounding a facility and the plume dispersion profile, different GISM formulations can generate significantly different results that can lead to different decisions depending on the risk-based decision framework being used.
Research conducted as part of a Cooperative Agreement between Research Triangle Institute (RTI) and EPA’s National Center for Environmental Assessment - EPA Contract Number CR-827136.
Go to . . .
2002 SRA Annual Meeting Table of Contents
2002 SRA Annual Meeting Author Index
Main Abstracts Menu Page
RiskWorld Home Page