11
Geographic Information Science
and Ecological Assessment
Janet Franklin
11.1 Introduction
Ecosystem management is carried out at a variety
of spatial and temporal scales (Franklin, 1993a,
1993b; Kohm and Franklin, 1997). Ecological assessment (EA) , however, especially ecosystem
characterization, generally has a landscape-scale
component and can hardly be conducted without
the use of a geographic information system (GIS).
Much of the biophysical and socioeconomic data
that form the basis of EA are in digital map format
(see Chapter 5), and carrying out EA requires that
these map themes be overlaid, compared, analyzed,
or used in a model (see Chapter 18), often in conjunction with nonspatial attribute data. Not long
ago, GIS was a somewhat daunting new technology with a steep learning curve, but in the last
decade it has become increasingly integrated into
research, land-use and land management planning,
ecosystem management, and related modeling at a
variety of institutions and agencies. Therefore, this
chapter will only briefly define GIS, point the
reader to a number of excellent texts on the subject, and concentrate on how GIS is used in EA.
Accordingly, the standard definition of GIS as a
computer information system "for the capture, storage, retrieval, analysis and display of spatial data"
(Clarke, 1995, p. 13) is enhanced by Goodchild's
(1985, p. 36): "a GIS is best defined as a system
which uses a spatial data base to provide answers
to queries of a geographical nature."
The following sections discuss definitions of geographic information systems and science (11.2);
The author is grateful to the anonymous reviewers and
the technical editors for improving the quality of this
chapter. I thank Patrick Bourgeron and Mark Jensen for
inviting me to participate.
institutional issues related to supporting a GIS for
EA (11.3); data sources for GIS-based ecological
assessments (11.4.1); effects of scale and accuracy
of spatially explicit data on ecological assessment,
analyses, and modeling (11.4.2 and 11.4.3); types
of spatial data analysis that can support EA (11.5);
and issues related to geographic information output (11.6).
11.2 What Is a Geographic
Information System?
Is GIS synonymous with GIS software? They are
sometimes treated as if they were because the software systems are complex and specialized. However, a GIS would have to include the geographic
database (digital maps, themes, or coveragesraster, point, line and polygon data), the software
used to organize both the locational and attribute
data (the information system) and to manipulate
and query it, and the hardware required to capture
or input the data (GPS, digitizer, scanner), manipulate and view it, and create hard- and soft-copy
output. This paraphrases the textbook definition of
a GIS, given above, and the components of a GIS
are described in a number of excellent texts and
references (Burrough, 1986; Star and Estes, 1990;
Tomlin, 1990; Maguire et al., 1991; Star et al.,
1997; Burrough and McDonnell, 1998; Clarke
1999). Also recommended is the National Center
for Geographic Information and Analysis (NCGIA)
GIS Core Curriculum Web site (http://ncgia.ncgia.
ucsb.edu:80/gisccl) and web references therein for
graphic introductions to GIS and spatial data analysis.
But is a GIS more than the sum of its parts? Burrough (1986, p. 7) asserted that the data in the GIS
151
Geographic Information Science
and Ecological Assessment
Janet Franklin
11.1 Introduction
Ecosystem management is carried out at a variety
of spatial and temporal scales (Franklin, 1993a,
1993b; Kohm and Franklin, 1997). Ecological assessment (EA) , however, especially ecosystem
characterization, generally has a landscape-scale
component and can hardly be conducted without
the use of a geographic information system (GIS).
Much of the biophysical and socioeconomic data
that form the basis of EA are in digital map format
(see Chapter 5), and carrying out EA requires that
these map themes be overlaid, compared, analyzed,
or used in a model (see Chapter 18), often in conjunction with nonspatial attribute data. Not long
ago, GIS was a somewhat daunting new technology with a steep learning curve, but in the last
decade it has become increasingly integrated into
research, land-use and land management planning,
ecosystem management, and related modeling at a
variety of institutions and agencies. Therefore, this
chapter will only briefly define GIS, point the
reader to a number of excellent texts on the subject, and concentrate on how GIS is used in EA.
Accordingly, the standard definition of GIS as a
computer information system "for the capture, storage, retrieval, analysis and display of spatial data"
(Clarke, 1995, p. 13) is enhanced by Goodchild's
(1985, p. 36): "a GIS is best defined as a system
which uses a spatial data base to provide answers
to queries of a geographical nature."
The following sections discuss definitions of geographic information systems and science (11.2);
The author is grateful to the anonymous reviewers and
the technical editors for improving the quality of this
chapter. I thank Patrick Bourgeron and Mark Jensen for
inviting me to participate.
institutional issues related to supporting a GIS for
EA (11.3); data sources for GIS-based ecological
assessments (11.4.1); effects of scale and accuracy
of spatially explicit data on ecological assessment,
analyses, and modeling (11.4.2 and 11.4.3); types
of spatial data analysis that can support EA (11.5);
and issues related to geographic information output (11.6).
11.2 What Is a Geographic
Information System?
Is GIS synonymous with GIS software? They are
sometimes treated as if they were because the software systems are complex and specialized. However, a GIS would have to include the geographic
database (digital maps, themes, or coveragesraster, point, line and polygon data), the software
used to organize both the locational and attribute
data (the information system) and to manipulate
and query it, and the hardware required to capture
or input the data (GPS, digitizer, scanner), manipulate and view it, and create hard- and soft-copy
output. This paraphrases the textbook definition of
a GIS, given above, and the components of a GIS
are described in a number of excellent texts and
references (Burrough, 1986; Star and Estes, 1990;
Tomlin, 1990; Maguire et al., 1991; Star et al.,
1997; Burrough and McDonnell, 1998; Clarke
1999). Also recommended is the National Center
for Geographic Information and Analysis (NCGIA)
GIS Core Curriculum Web site (http://ncgia.ncgia.
ucsb.edu:80/gisccl) and web references therein for
graphic introductions to GIS and spatial data analysis.
But is a GIS more than the sum of its parts? Burrough (1986, p. 7) asserted that the data in the GIS
151