Urban Security
The Urban
Security Project is a multi-disciplinary research effort
dealing with the relationship among urban infrastructures (e.g.,
power , transportation, and sewer systems) and the natural environment
(e.g., floods, earthquakes, meteorology). The multi-disciplinary
nature of the project involves researchers from across the Laboratory
with backgrounds in such areas as computer architecture, atmospheric
sciences, geographical information systems, applied mathematics,
sub-surface transport, water chemistry, transportation, database
management, electrical power systems, geophysics, environmental
engineering, and air quality. Below, we describe two components
of the Project that deal with atmospheric transport and diffusion
modeling.
Airborne Toxic Release/Emergency Response Sub-component.
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| Plume dispersion over N. Dallas simulated
using the HOTMAC - RAPTAD - GASFLOW modeling system. |
As part of the first-year pilot project, the dispersion of a toxic vapor spill
was simulated in north Dallas. The simulation involved modeling flow and plume
dispersion around two buildings and then tracking the plume over several kilometers.
The microscale modeling was performed using a computational fluid dynamics model
called GASFLOW and the mesoscale modeling was done with
the HOTMAC-RAPTAD system. The toxic plume concentration
fields were then used along with transportation simulations performed by the TRANSIMS team
to compute exposures to the cars traveling through the plume.
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Urban Air-Water Pathways
Sub-component.
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| Nitrogen dioxide deposition simulated over
the Santa Monica Bay Watershed using the CIT air chemistry code. |
We are attempting to simulate the transport of pollutants from their source
through air and water pathways in an urban environment by linking cross-disciplinary
subsystem models, tailoring them for urban applications, and writing interface
physics modules. We are focusing on the transport and fate of nitrates
because 1) they track through both the air and water pathways, 2) the physics,
chemistry, and biology of the complete cycle is not well understood, 3)
nitrates have important health, local ecosystem, and global climate implications,
and 4) the problem requires us to stretch our capabilities in non-traditional
areas, including several relating to urban infrastructure and security.
Currently, we are simulating the fate of nitrates in the Los Angeles basin
from their beginning as nitrate-precursors produced by auto emissions and
industrial processes, tracking their dispersion and chemistry as they are
transported by regional winds and eventually wet or dry deposit on the
ground, tracing their path as they are entrained into surface water runoff
and the stormwater system during rain events and then carried into a receiving
water body where dispersion and biologically-mediated chemical reactions
take place.
We have developed collaborations with leaders in different fields
to complement our research efforts, including Carnegie-Mellon and
Georgia Tech Universities (size-resolved particulate chemistry
modeling), the UCLA Dept. of Civil Engineering (urban runoff modeling
and water quality datasets), the LA Stormwater Bureau and LA Public
Works Dept. (stormwater datasets and end-user expertise), the Univ.
of Alabama Dept. of Civil Engineering (stormwater modeling), and
the UCLA School of Public Health (biologically-mediated chemistry).
Currently we are supporting five graduate students, two of whom
are working at LANL on their Ph.D. dissertations. The team includes
members from the EES, D, and CST divisions.
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Reports & Talks:
 Slides
containing an overview of the Urban Air-Water Pathways research
task.
Download
0.75 Mb pdf
Modeling
the atmospheric deposition and stormwater washoff of nitrogen
compounds, Burian, Streit, McPherson, Brown, and Turin, Env.
Mod. & Soft., v 16, pp 467-479, LA-UR-99-6256 (2001).
Download x.x Mb pdf
Evaluation
of land use/land cover data sets for urban watershed modeling, Burian,
Brown, and McPherson, IWA 5th Int. Conf. Diffuse/Nonpoint Poll. & Watershed
Management, Milwaukee, WI, LA-UR-01-4549 (2001).
Download
0.1 Mb pdf
View
the presentation on Evaluation of land use/land cover data sets
for urban watershed modeling.
Download x.x Mb pdf
Pollutant
transfer through air and water pathways in an urban environment, Brown,
Burian, McPherson, Streit, Costigan and Greene, 2nd AMS Urban
Env. Conf., Albuquerque, NM, LA-UR-98-3527 (1998).
Download
0.1 Mb pdf
View
quicktime movies of storm water flow (0.8 Mb) and storm water quality (0.7 Mb) in one
of the Santa Monica Bay sub-watersheds. |
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Environmental
modeling and assessment using detailed urban databases, Burian,
S., T. McPherson, M. Brown, G. Streit, and H.J. Turin, Earth
Sciences in the Cities, AGU Monograph, eds. Heiken, Fakundiny,
and Sutter, LA-UR-01-2393 (2001).
Integrated
Environmental Modeling of the Urban Ecosystem, T. McPherson,
S. Burian, M. Brown, G. Streit, and H. Turin, Earth Sciences
in the Cities, AGU Monograph, eds. Heiken, Fakundiny, and Sutter,
LA-UR-01-2348 (2001).
Development
of a stormwater model for the Ballona Creek Watershed, Burian,
McPherson, Brown, and Turin, LA-UR-00-1849 (2000).
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0.5 Mb pdf
Air
and water quality modeling system: application to the Los Angeles
metropolitan area, Brown, Burian, McPherson, Streit, Costigan,
and Turin, 2nd AMS Conf. on Env. Appl., Long Beach, CA, Jan 2000,
LA-UR-99-5468 (1999).
Download
0.4 Mb pdf
Modeling
the Atmospheric Contribution of Nitrogen Compounds in Stormwater
Runoff, Burian, Streit, McPherson, Brown, and Turin, 11th
AMS Appl. Air Poll. Meteor. Conf., Long Beach, CA, Jan 2000,
LA-UR-99-5218 (1999).
Download
0.4 Mb pdf
Visit
the Urban
Security Project Site
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