Final Report
Project Title: An Integrated Cross-Border GIS for the San Diego-Tijuana
Interface
SCERP Project Number: AQ94-8.2
Principal Investigator: Richard D. Wright and Ernst C. Griffin
San Diego State University
Goal: This is the second year of a three-year program involving
the development of a comprehensive geographic information system (GIS),
for the San Diego-Tijuana interface and its use in addressing a set of
border environmental concerns.
Rationale: The San Diego/Tijuana metropolitan area, now exceeding
three million inhabitants, is the largest urban concentration on the United
Sates-Mexico border. The social, economic and environmental interactions
between the populations on either side of the border have increased in
volume and intensity in recent years. Unfortunately, in many ways the international
border remains a significant barrier which impairs the understanding of
many basic problems and impedes the resolution of numerous applied policy
issues. In anecdotal terms, this probably is most graphically reflected
by the fact that many maps published on either side of the border leave
the other side blank. Virtually everyone who has conducted research on
the border region has confronted problems of data accessibility and compatibility.
This problem is not restricted to socioeconomic measures, but also is true
of most physical parameters as well. Thus, there is a major need for a
comprehensive cross-border GIS data base which can be used as a foundation
for systematic research.
Approach:The purpose of this project is to create a GIS for the
San Diego- Tijuana interface and examine its utilization in a set of environmental
concerns. The goals of the research are:
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to create an integrated GIS along the border between the County of San
Diego, USA and the Municipio de Tijuana, Mexico.
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to integrate air pollution analysis and GIS techniques in the San Diego-Tijuana
interface.
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to document urban expansion in Tijuana and examine its impact on pollution.
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to extend natural habitat database development south of the border.
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to integrate and train researchers from Mexico and the U.S. in border GIS
research.
Status: This is the second year funding of a three-year program.
It builds on the exploratory work done under first year funding. The status
of each task for which work was done with second year funding is detailed
in the following paragraphs:
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Creation of an integrated GIS along the border between San Diego and Tijuana.
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During the funding period San Diego State University (SDSU) and El Colegio
de la Frontera Norte (COLEF) continued to develop and integrate digital
environmental data for the two jurisdictions. Currently, SDSU is producing
an improved elevation layer by scanning and editing USGS 1:24,000-scale
contour maps. This layer will replace the interim DEM created during the
first year of funding. We had hoped to complete the improved DEM by the
end of the second year, but because of the large amount of editing that
needs to be done on the scanned data, it is anticipated that this task
will not be completed until July 1996.
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During the past year, we automated the soils layer for San Diego County.
This database was derived by digitizing approximately 50 1:24,000-scale
Soil Conservation Survey maps. The hydrography layer also received our
attention during Year 2 of the project. To date we have automated the blue
line features from 40 1:24,000-scale USGS quadrangles.
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Integration of air pollution analysis and GIS.
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To accomplish this objective, the researchers will estimate the spatial
characteristics of solid particulate matter generated by vehicles on the
streets of Tijuana. To estimate emissions, three sets of data are being
compiled: a) street network and street surface characteristics (20 percent
completed), b) a land use database for Tijuana (completed during Year 2),
and c) field sample data including traffic volume, vehicle speed, vehicle
type, and number of wheels per vehicle.
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Another aspect of air quality modeling on which we are working is that
owing to industrialization in Tijuana. The model that will be used is the
World Bank's Industrial Pollution Projection System (IPPS). It is designed
primarily for developing countries in order to estimate industrial emissions
based on the scale of industrial activity, its sectorial composition, and
the process technologies being employed. The model produces information
on toxic pollutants for air, water and land. There are separate estimates
for air for over 100 toxic pollutants. The pollutants are estimated on
the basis of ISIC codes and employment numbers. The ISIC codes being used
are the 4-digit codes derived from SIC codes or listings of products. We
are working with three sources of industrial data for Tijuana and evaluating
which one or combination will be the most accurate, efficient and manageable
in terms of georeferencing. Once this has been decided, it is a matter
of finalizing the database and implementing the model, which consists of
calculations for the various pollutants for each ISIC code. The output
from the model will be incorporated into the GIS and analyzed in terms
of spatial relationships. Results from the modeling will be available in
approximately six months.
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Urban expansion in Tijuana and its impact on pollution.
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The majority of work this year concerned gathering and compiling data to
support the modeling of urbanization and population growth in Tijuana.
Specific tasks included interpretation of aerial photography, drafting
of land use polygons, processing and editing of these digital data in ARC/INFO,
and the development of a series of land use maps. Preliminary maps from
this effort are being field checked for accuracy utilizing a GPS. Imagery
examined included 1972, 1980, and 1994 aerial photographs at various scales.
This imagery was interpreted to generate a general land use classification
with 13 classes and a residential housing quality classification with six
classes. The intention is to provide a historical trend of land use and
population growth for Tijuana. This, in turn, will be used to generate
future projections of these phenomena. The overall goal of this work is
to investigate the relationships and interactions between the aforementioned
processes and the environmental quality of the region.
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Extended natural habitat database development south of the border.
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During the past three years, SDSU worked with SANDAG and other entities
to map and automate vegetation data. The San Diego portion of the project
has been completed using the Holland vegetation classification and, with
the procurement of aerial photography and satellite imagery, we are well
into the process of mapping vegetation on the Mexican side using the same
classification. Currently, researchers are delimiting vegetation types
on large scale (1:12,500) aerial photographs using a combination of field
and laboratory techniques. The vegetation polygons are then automated on
a SPOT satellite image background using a heads-up digitizing approach.
This process is going well and we expect it to be completed in Year Three
of the project.
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Integrate and train researchers from Mexico and the U.S. in border GIS
research.
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GIS training is being accomplished in three principal ways. First, we meet
with our counterparts from COLEF and other Mexican institutions on a regular
basis to discuss technical issues of data sharing, data integration, and
GIS standards. Second, we submitted a proposal for funding to the Department
of Commerce to improve the telecommunications and GIS infrastructure between
the U.S. and Mexico in conjunction with this project. Unfortunately, the
project was not funded but we continue to look for ways to improve the
process of integrating data across the border. Third, a two-day workshop
focusing on environmental applications of GIS along the border is tentatively
scheduled for April 1996. This workshop, to be attended by approximately
20-30 persons from the U.S. and Mexico, will be sponsored by San Diego
State University, El Colegio de la Frontera Norte, the University of Utah,
Arizona State University, New Mexico State University, and the University
of Texas, El Paso.
Practical Use: A wide range of users from the public and private
sectors have and will have access to the GIS database. Examples of users
include:
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Environmental consultants who need to conduct environmental risk analyses
along the border.
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Researchers who wish to delimit transborder sensitive habitat preserves.
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Public sector employees on both sides of the border sources of air pollution.
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Educators who wish to employ GIS to teach their students a wide variety
of border environmental issues.
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Members of the private sector who wish to employ geospatial data for the
border region to respond to opportunities made available because of NAFTA.
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Other SCERP/EPA researchers who are conducting border studies that require
the use of digital environmental data.
Other Personnel: Collaborators at other institutions are:
Dr. George Hepner, Department of Geography, University of Utah.
Dr. Alain Winckell, El Colegio de la Frontera Norte, Tijuana.
Related SCERP-supported projects:
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