HYDROMAP: Predicting Global Currents
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Accurately predicting the movement of oil,
chemicals and other pollutants in the ocean
requires detailed hydrodynamic flow fields.
In the past, ASA has used existing data
or developed customized hydrodynamic data
by applying location-specific hydrodynamic
models to new areas. To simplify this process
and reduce the time needed to create high-resolution
hydrodynamic data, ASA has developed a globally
re-locatable hydrodynamic model, HydroMap.
Global databases for coastline, bathymetry
and wind data are readily available, and
automatic gridding tools allow users to
very quickly set up and execute the transport
models. HydroMap is designed to generate
reliable predictive current data quickly
for any new area.
HydroMap is a Windows application with
a GIS-based interface, similar to ASA's
other map-based applications, and allows
the user to easily access and input the
required data for the current data simulation.
The underlying hydrodynamic model solves
the equations of motion for the water movement
in a single simulation and outputs current
data that may be automatically linked to
OILMAP, CHEMMAP, DREDGEMAP and ASA's other
models.
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A key feature of HydroMap is its
novel grid structure, which enables
several levels of grid size to be
constructed and executed at the
same time. Gridding tools within
the HydroMap system allow the user
to create a rectangular grid system
and easily select locales within
that grid structure for finer grid
resolutions. The improvement in
gridding strategy permits the complex
geometry of a river-estuarine system
to be handled simultaneously with
the open geometry of the coastal
shelf.
The underlying hydrodynamic model
uses continuous profiles to represent
the velocity, temperature, and salinity
in the vertical. The data required
by HYDROMAP to grid and force simulations
worldwide are: coastline definition
to define the land-water boundary,
bathymetry contours or soundings
to define the depth of water cells
in the grid, tidal elevation constituent
harmonic definitions (elevation
and phase), and the option of long
term wind stress forcing. Publicly
available sources for these data
are either packaged with HYDROMAP
or can be easily accessed through
HYDROMAP tools. The example figure
shows a detail of a HYDROMAP application
to Singapore waters.
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Making Waves with WAVEMAP
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Waves entering the coastal environment
undergo significant changes as they
encounter varying depths, man-made
structures, strong currents and
changing wind conditions. Wave behavior
is very important to coastal managers,
developers and landowners studying
such topics as beach erosion, growth
of offshore sand bars and the construction
of break waters and other man-made
structures.
To address these issues, ASA has
developed WAVEMAP, a wave-modeling
software package integrated with
a Geographical Information System
(GIS). Wave simulation is initiated
through the use of interactive forms
that allow the user to specify the
incident wave properties, direction
of propagation, relative angle and
other model parameters. The model
output can be viewed as scalar contours
of wave height, as vectors depicting
wave height and direction of travel
or as a three-dimensional surface.
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WAVEMAP employs the combined refraction-diffraction
wave model REF/DIF to predict the progress
of an incident monochromatic wave within
regions of complex geometry and bathymetry.
REF/DIF solves the parabolic approximation
of the mild slope equation and has the ability
to dissipate wave energy due to several
physical mechanisms such as wave breaking,
surface films, bottom friction and laminar
or turbulent boundary layers. An important
feature of WAVEMAP is its ability to simulate
wave-current interactions. This is accomplished
by defining current fields through a direct
linkage to WQMAP, the hydrodynamic model
within ASA's water quality and hydrodynamic
modeling system.
WAVEMAP allows for the development of grids
and associated bathymetry directly on the
geographic map. The user simply defines
the area of interest using the cursor and
then enters the grid dimensions and rotation
angle. The grid is automatically generated
taking into account bathymetry, landmasses
and man-made structures within the specified
domain.
The WAVEMAP system enables analysis of
the coastal wave environment by engineers,
scientists, managers and regulators. Recently
ASA applied WAVEMAP to assess the effects
that reconfiguration strategies of the Route
78 bridge/causeway over Missisquoi Bay in
Lake Champlain would have on the local coastal
profile. Applied Technology and Management
(ATM) used WAVEMAP to evaluate the impacts
of proposed deepening of the Savannah (Georgia)
Harbor Navigation Channel and to assess
the borrow site dredging impacts on the
local wave environment at Indian River County,
Florida.
CHEMMAP: A
Model and Information System for Chemical
Spill Responses
A tanker carrying 3,000 tonnes of benzene
is sending out distress signals reporting
a hole in its hull as gale force winds whip
up 30-foot seas, sending waves crashing
over the bow. On the surface of the water
a sinuous, iridescent trail extends toward
the horizon aft of the ship. What will be
the fate of these spilled chemical products?
ASA has developed CHEMMAP, an integrated
response and impact analysis tool for chemical
spills, to address questions such as this.
CHEMMAP predicts the trajectory
and fate of a wide variety of chemical
products, including floating, sinking,
soluble and insoluble chemicals
and product mixtures. CHEMMAP contains
ASA's imbedded Geographic Information
System (GIS) and a 3D spill model
that predicts the movement of chemicals
in the water. The spill model relies
on environmental data such as wind
and currents, physical data such
as the proximity of shorelines,
and chemical data that define the
chemical's properties.
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The chemical database contains data
for over 800 chemicals. In addition
to the quantitative chemical data
available for each chemical, such
as density, vapor pressure, solubility
and partition coefficients, the chemical
database provides extensive qualitative
information. There is a description
of general behavior that informs the
user how the chemical will act upon
release. Warnings are provided for
potentially hazardous chemicals. A
general explanation of the chemical,
as well as information about the reactive
groups to which it belongs, is included
in the CHEMMAP chemical database. |
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Toxicity data included in the chemical database
can be used to produce a hazard quotient (ratio
of the predicted environmental concentration
to the value of the toxicity parameter of
interest) in the CHEMMAP model output display.
In the hypothetical spill mentioned above,
the user can access the database to determine
that benzene will float, evaporate rapidly
and is highly soluble. There is no rapid reaction
with water or air. CHEMMAP's atmospheric model
may then be used to predict the dispersion
of the atmospheric plume.
Personnel News
Matt Ward delivered and provided
training on the latest version of WQMAP
to Massachusetts Coastal Zone Management
(MCZM). MCZM will be applying a calibrated
version of BFHYDRO to study water quality
issues within Salem Sound Massachusetts.
In January, Eoin Howlett and Eric
Anderson visited the U.S. Army Corps
of Engineers in Vicksburg, Mississippi at
the Environmental Research & Development
Center. They attended a meeting discussing
ERDC's dredging fate models and the associated
interfaces that have been developed by ASA.
Deborah French McCay presented two
papers at the International Oil Spill Conference
March 26-29 in Tampa, Florida. The first,
"Quantifying the Scale of Restoration
Required to Compensate for the Impacts of
the North Cape Oil Spill on Fish and Invertebrates",
describes modeling methods for calculating
the amount of restoration that would provide
equivalent ecological and human services
to those lost because of a spill. The second
paper, "Oil Spill Modeling for Contingency
Planning and Impact Assessment and Example
Application for Florida Power and Light",
describes probabilistic modeling for ecological
risk assessment.
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Eric Anderson presented
a paper on the SSFATE (Suspended
Sediment FATE) Model at the 16th
World Dredging Congress and Exhibition
held in Kuala Lumpur, Malaysia on
2-5 April. SSFATE is a system developed
for the US Army Corps of Engineers
to define the movement of sediments
released during dredging operations.
The wetland flower and palm trees
photos were shot during a visit
to a Malaysian wetland site, the
Paya Indah Wetlands, arranged by
the conference hosts.
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ASA recently delivered
the latest version of OILMAP to the Exploration
and Production arm of Petronas Carigali
(Kirteh), the national oil company of Malaysia.
Roddy Thomas completed a training
program for the new HSE oil spill response
and planning team of PC Kirteh.
Daniel Mendelsohn will chair a session
at the EnviroExpo 2001 to be held at the
World Trade Center, Boston, Mass., Thursday,
May 10, 2001, from 1:30 - 5:00. The session
is part of Track 3.2 Water Quality and Watershed
Analysis: Rules and Practice, titled Tools
for TMDL Development and Case Studies. Speakers
include Steven Chapra, Tufts Univ.; Ray
Wright, Univ. of Rhode Island; Chris Turner,
RIDEM and William Saunders, ASA.
To learn more about the EnviroExpo 2001
visit there website at http://www.EnviroExpo.com.
Deborah French, seeking consistency
between her personal and professional life,
is now using her full name Deborah P. French
McCay on papers and reports. French is a
previous married name, McCay is her new
married name, and P is for Perryman, her
maiden name (which would have been the wise
choice originally!) She responds to any
of the above.
Roddy Thomas recently delivered
the latest version of OILMAP to the operational
HSE dept. of Chevron, Aberdeen UK. Mrs.
Alex Duff, the Environmental Specialist
Coordinator, received an initial training
course. The model program will be used primarily
for planning and emergency response in North
Sea waters.
Matt Ward and Eric Anderson traveled to Ciudad Carmen, Mexico
for a startup meeting for the PEMEX
Hurricane Evacuation project on
6-8 March. The project is designed
to develop a system to define specific
evacuation strategies for the evacuation
of PEMEX and contractor personnel
from offshore structures under hurricane
threat. Miguel Palet, of GDS de
Mexico, ASA's partner in Mexico
and Sergio Millan del Rio of PEMEX
met with operations and meteorological
personnel to coordinate data management
issues and refine the needed functionality
for the system. Matt, Miguel, and
Sergio are shown outside Sergio's
office.
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March 12-15, Deborah French McCay
visited Venezuela and provided model training
to INTEVEP, the research division of the
Venezuelan oil company PDVSA. INTEVEP uses
ASA's models SIMAP and CHEMMAP for spill
response, contingency planning and ecological
risk assessments.
Eoin Howlett visited the Irish Coast
Guard (formerly known as the Irish Marine
Emergency Services) in Dublin to deliver
CHEMMAP and provide training. The Irish
Coast Guard use OILMAP, SARMAP, and CHEMMAP.
New Faces
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Alivia Ruth Saunders was born to
ASA's Bill Saunders and his
wife Betsy on March 25, 2001. She
made her debut a couple of weeks
early and spent her first week touring
Rhode Island's fine hospitals, but
she is now home doing fine and is
getting accustomed to life in the
Saunders household. Mom and Dad
are napping when they can.
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A warm welcome to Betsy Labonte,
who is replacing Leslie Smith as
ASA's Office Manager. Betsy hails
from Wakefield, Rhode Island and
comes to us from Kent Surgical Associates
in Warwick, RI. We wish Leslie the
best of luck with her new job and
new home in New Hampshire.
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