Table of Contents - The Atmospheric Studies Group at TRC

Section 9: CALPUFF
Table 9-64 summarizes the OPTHILL input and output filenames. OPTHILL requires a single input file
(OPTHILL.INP) which contains the user's inputs describing the terrain profile, each height, and
maximum axis length. The computed values of EXPO and SCALE for one axis of the hill are listed in the
output list file (OPTHILL.LST). The format and contents of the OPTHILL control file are explained in
Table 9-65.
9.16.2 Example OPTHILL Application
The OPTHILL program is an optimization that takes a value of "relief" and "axmax," and a sequence of
pairs of (x,ht) values along an axis, and returns a value of "expo" and "scale" that prescribes the profile
function that best matches the (x,ht) pairs. Its use is illustrated by the following example.
Figure 9-2 shows the terrain surrounding the site of EPA's "Full-Scale Plume Study" (FSPS) that was
performed in the Truckee River Valley near Reno, NV (Strimaitis et al., 1985), as part of the Complex
Terrain Model Development Program. Nocturnal flow in this valley is frequently channeled by the high
terrain to the north and south of the Tracy power plant. Elevations typical of nocturnal plume heights
(4600-4800 ft. MSL) are emphasized on the figure. Given the predominant flow to the east during stable
conditions, there is potential for plume impact on the feature just northeast of the plant. This feature,
marked by axes in Figure 9-2, was named "Beacon Hill" during the study.
Following the procedures outlined above, axes were drawn over the feature and distances between fixed
contour elevations were tabulated. After subtracting the elevation above sea level of the base of the
feature (the floor of the river valley), these data were entered into two files. Table 9-66 displays the
contents of both files. The files (axis1.inp and axis2.inp) contain "relief" and the value for "axmax" for
each axis of the hill, followed by five pairs of (x,ht) values. The first record of each file is reserved for
comments to identify the data. Values for "relief" and "axmax" are free-format, and should be entered
anywhere in the open space provided on the next two lines. Pairs of (x,ht) should be entered right after
the next comment record.
OPTHILL must be invoked separately for each of the two axes of the hill. This is accomplished by
renaming one input file (e.g., axis1.inp) to the OPTHILL input control file name (OPTHILL.INP),
executing the program, renaming the output file (OPTHILL.LST) to a new name (e.g., axis1.lst), and then
repeating these steps for the second axis of the hill. The output files produced by OPTHILL for the
current example are presented in Table 9-67 and 9-68. The output file lists the final values of the profile
parameters, and it also lists the profile data provided by the user along with the corresponding data
computed from the profile parameters.
9-325