A GIS-Based Methodology Using Wind Speed, Frequency and Direction to Model Airborne Material Transport for Selection of Nuclear Materials Transportation Routes

摘要

Researchers at the University of Missouri have previously utilized a geographic information system to develop methodologies to support route-selection for roadway nuclear materials transportation. These analyses considered road characteristics, wind speed, frequency, and direction, and potential population impacts from a transportation incident. Wind roses were used to describe the frequency of wind direction and intensity and the potential influence on airborne nuclear material transport. A population concentration parameter was developed to evaluate points on alternative transportation routes by modeling airborne material concentrations in any one of 16 possible resulting directional plumes. Building on this work, the methodology has been extended to create transformations that rotate and translate the x-y coordinate systems for calculated dispersal plumes from a system based on wind direction to a common coordinate specification that can be used for plumes generated in any one of the 16 directions of a wind rose. In addition, a frequency-based weighting of contaminant concentrations in the plume is applied. This weighting accounts for the fact that wind may be blowing from any one of 16 different directions if an incident occurs, potentially impacting different portions of a community. The new methodology permits route planners to compare normalized incident impact values as before, but also provides information describing the composite probabilistic concentration gradients and the coordinates of their spatial extents. This allows for enhanced impact analysis for determining those potentially affected by a transportation incident and provides guidance in alternative route selection. Wind data from Barkley Regional Airport, near Paducah, Kentucky, was again used for the demonstration.