| Summary: | 博士 === 國立臺灣大學 === 環境工程研究所 === 82 === The complex building setting in urban shall induce complicated
dispersion phenomena which is of microscale problem. On the
basis of 2-D ROADWAY model, this study improve the numerical
ROADWAY model to be of 3-D microscale model, and capable of
treating the effect caused by building, and include the effect
of vehicle- induced wake. The developed 3-D roadway model
assume the validity of surface similarity theory, Eskridge
vehicle-induced wake theory, vehicle speed much greater than
wind speed, building setting continuously along roadway, no
removal effect, and used only in the conditions of wind
direction parallel to roadway, inert gas dispersion. The
simulated concentrations comparing with measured data, input
with actual traffic flow and wind data, at four stations by
Taipei mainroad showed the difference averages of station were
in the range of 1.5~3 ppm(as CO). The sensitivity analysis by
the 3-D model found the factors were more sensitive to roadway
concentration: emission rate (emission factor, traffic flow,
vehicle speed), position of receptor, wind speed, building
configuration. The study conducted commuting-pattern survey by
questionnaire method in selected district, Taipei, and
performed personal CO exposure measurements in the roadway-
related micro- environments: automobile, motorcycle, bus, bus
stop, walkway, residential and school areas, then estimate the
1-hour and 8-hour exposure in roadway by Monte-Carlo
Simulation. The study found the commuting pattern in Taipei is
different from that in U.S.. Regarding the 1-hour commuting
exposure, commuters by bus and motorcycle modes were worse.
The 8-hour exposure for driver (working in main roadway) and
workers in offices were under- predicted and overpredicted,
respectively, by the roadside fixed monitoring stations. The
representativeness of fixed monitoring by roadside was limited
to the people working at walksides only.
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