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Towards Geodesign: Repurposing Cartography and GIS?
Michael F. Goodchild, Ph.D. | good@geog.ucsb.edu
Center for Spatial Studies
Department of Geography
University of California, Santa Barabara
Santa Barbara, CA 93106-4060
R E P L A C E W O R D C L O U D
A B S T R A C T
One of the original visions for GIS was as a tool for creating designs, but
GIS has evolved in numerous other directions. Definitions of geodesign
are reviewed, together with a short history of the concept. A distinction
is drawn between Design and design, the latter being addressed through
spatial decision support systems, and the former being seen as a superset of
the latter. Geodesign also has a strong and well-defined relationship with
cartography. The vision of landscape architecture propounded by the late
Ian McHarg also provides a foundation for geodesign. Two existing gaps
in the geodesigns computational tools are identified: support for sketch
and implementation of models representing scientific knowledge of how
the world works. Two important areas of research are identified that would
address problems that currently impede geodesign.
I N T R O D U C T I O N
Although there are many historic roots of geographic information systems
(GIS; Foresman 1998), one of the strongest lies in the notion of making
design decisions by overlaying maps, each map representing one of the
Cartographic Perspectives, Number 66, Fall 2010
Article Title Author Name(s) | 55
factors important in the decision. The net effect of each of the factors would
be represented by the amount of light penetrating the layers at each point,
allowing the decision maker to make an intuitive judgment as to the best
solution. This is one of the central ideas of McHargs (1969) Design with
Nature, and the stack of layers has become an icon of the entire field of GIS,
appearing on the front covers of many of its textbooks. One of the strongest
arguments for GIS has been its ability to place such a simple and intuitive
concept as overlaying transparent maps on a solid, reproducibleone might go
so far as to say objective and scientificfooting. Abundant examples of this idea
can be found in the fields textbooks, ranging from site selection for industrial
plants to routing of power lines or highway corridors.
However, in the four decades that have elapsed since its birth, this notion
of GIS as improving the process of design has become less central. GIS has
evolved into a tool for performing spatial analysis in support of scientific
discovery, a system for managing inventories of spatially distributed assets, a
platform for automating the cartographic process and displaying information
in map form, and a medium for communicating what is known about the
surface and near-surface of the planet (Sui and Goodchild 2001). Yet we
increasingly are aware of the planets fragility, and of the need to make wise
decisions about its future that are informed by evidence and by the best
scientific knowledge. Now, more than ever, we need a technology of design
that can work in tandem with human decision-making processes, bringing
what we know about how the planet works to bear on the decisions that have
to be made about its future. Humans have the power both to destroy the planet
and to sustain it. We need tools that can predict for us the effects of tinkering
with the Earth system, thus helping us to be effective stewards of the only
planet we have.
This concept of science-based design sits at the interface among several
disciplines. It involves the disciplines that traditionally have concerned
themselves with design, including planning and landscape architecture. But
it also involves the disciplines that acquire and accumulate fundamental
knowledge about how environmental and social systems operate, including
geography, ecology, hydrology, earth science, sociology, economics, and political
science. Finally, it includes the new disciplines of information technology,
especially geographic information science (GIScience; Goodchild 1992). Input
from all three of these sets is needed if decisions are to be supported by well-
designed and powerful tools that are easy to use, and by the results of good
science.
Over the past decade, there have been several discussions of the need to close
what many have perceived as the growing gap between GIS and design.
In January 2001, a workshop was held in Santa Barbara, California on
Landscape Change, organized by a joint committee of landscape architects
and GIScientists (http://www.ncgia.ucsb.edu/landscape/landscape.htm). A
second workshop on Spatial Concepts in GIS and Design was held in Santa
Barbara in late 2008 (http://www.ncgia.ucsb.edu/projects/scdg/). The term
geodesign was suggested as a useful umbrella term for this examination of the
common ground between GIS and design, with its implied emphasis on the
Now more ThAN
ever we Need
A TeChNology
oF desigN ThAT
CAN work iN
TANdem wiTh
humAN deCisioN-
mAkiNg ProCesses,
briNgiNg whAT
we kNow AbouT
how The PlANeT
works To beAr oN
The deCisioNs ThAT
hAve To be mAde
AbouT iTs FuTure
56 | Article Title Author Name(s)
Cartographic Perspectives, Number 66, Fall 2010
geographic domain and geographic scales. Most recently, in January 2010
the first GeoDesign Summit was convened in Redlands, California (http://
www.geodesignsummit.com), bringing together GIS and design practitioners
from academia, non-governmental organizations, government agencies, and
the private sector, with over 150 participants from across a wide range of
disciplines.
This paper presents one persons view of the nature of geodesign, of its
objectives, of how the field might be conceptually framed, of its relationships
to existing fields (especially cartography and GIS), and of research issues that
need to be addressed if current impediments to effective geodesign are to
be removed. The remainder of the paper is organized as follows. The second
section reviews alternative definitions of geodesign, its domain of application,
and its cognate disciplines. The third section discusses the McHarg vision and
its limitations, updates it to the present day, and presents a brief critique. The
fourth section describes the tools and computing environment that would be
needed to support a fully-fledged practice of geodesign. The final section ends
with some suggestions for future developments. The discussion is inevitably
personal, with no implication that all possible topics and arguments have
been covered. Nevertheless, the paper may provide a useful increment in our
understanding of the nature of geodesign and of what needs to be done to
move its agenda forward.
W H AT I S G E O D E S I G N ?
D e f i n i t i o n s
The GeoDesign Summit website quotes Carl Steinitz: Geodesign is
geography by design, a compellingly simple definition. If geography is the
set of processes that operate on or near the Earths surface, together with
the forms that result from such processes, then geodesign is concerned with
manipulating those forms and intervening in these processes to achieve specific
objectives. Thus, it is normative in the sense that decisions are made about
aspects of the geographic domain in order to achieve specified objectives, or
norms. Normative efforts stand in contrast to the traditional aim of science, to
discover general truths about the world; geodesign is interventionist in contrast
to the more detached and dispassionate nature of pure science. Geodesign
seeks to improve the world, whereas traditional science seeks only to provide
the basis of knowledge on which the world might eventually be improved.
Pure science is often carefully partitioned from application, and often sees
its responsibilities as discharged when results have appeared in the pages of
refereed journals. In that sense, geodesign lies within the domain of applied
science and engineering, seeking ways of addressing practical problems using
the scientific method.
Wikipedia defines geodesign as a set of techniques and enabling
technologies for planning built and natural environments in an integrated
process, including project conceptualization, analysis, design specification,
Cartographic Perspectives, Number 66, Fall 2010
Article Title Author Name(s) | 57
geodesigN
is PlANNiNg
iNFormed
by sCieNTiFiC
kNowledge oF
how The world
works, exPressed
iN gis-bAsed
simulATioNs
stakeholder participation and collaboration, design creation, simulation, and
evaluation (among other stages). The emphasis here is on built and natural
environments, or Steinitzs geography, and also on the integration of the
entire design process, presumably through technology.
Both of these definitions imply a very broad and traditional interpretation of
the planning process. Others, however, have focused more on how planning
can take advantage of the capabilities of GIS. Wikipedia also quotes
Flaxmans address at the GeoDesign Summit: Geodesign is a design and
planning method which tightly couples the creation of design proposals
with impact simulations informed by geographic contexts. In other words,
the ability of modern GIS to create highly compute-intensive simulations
of the effects of design scenarios provides an additional dimension to
the traditional planning process, with its emphasis on visual display and
intuition: geodesign is planning informed by scientific knowledge of how the
world works, expressed in GIS-based simulations. In a similar, though less
compute-intensive vein, and quoting Jack Dangermond from the GeoDesign
Summit website, Imagine if your initial design concept, scribbled on the
back of a cocktail napkin, has the full power of GIS behind it. The sketch
goes into the database, becoming a layer that can be compared to all the
other layers in the database. Clearly, comparison of layers is only one of the
multitude of functions that are easily invoked with todays GIS. Nevertheless,
sketch and simulation provide two distinct notions of how the computational
environment of a GIS might support geodesign.
One might also compare geodesign with other more widely recognized and
traditional terms, such as computer-aided design (CAD). GIS has often been
distinguished from CAD (Cowen 1988) by its emphasis on a geographic
reference system, the richness of the attributes associated with features, its
ability to deal with continuous fields (Couclelis 1992) in addition to discrete
objects, and its rich set of analytic and modeling functions. In essence, the
emphasis in CAD is on designing a structure through digital representation;
in GIS it is on analyzing and modeling the structures present in the social
and environmental worlds; and in geodesign it is on user-driven intervention
in those worlds.
spat i a l o p t i m i z at i o n
There is a long tradition of finding optimal solutions to design problems in
the research domain known as spatial optimization. Much of this literature
concerns finding optimal locations for point-like facilities, such as schools,
fire stations, retail stores, or restaurants (Ghosh and Rushton 1987).
Numerous problems have been formulated, depending on the exact nature of
the application, the objectives and constraints that apply, and the nature of
the space within which optima are sought. For example, the field of location-
allocation concerns the search for one or more locations for point-like
facilities to serve a dispersed demand, and solutions involve both the optimal
locations of the facilities and the service areas that each will cover.
58 | Article Title Author Name(s)
Cartographic Perspectives, Number 66, Fall 2010
More generally, spatial optimization problems can be characterized by
the type of information represented by the solution. Some problems seek
optimal locations for points, some for lines (e.g., transmission corridors),
and some for areas (e.g., optimal allocation of land for specified uses). Some
problems seek optimal allocations of one set of features to another, as in the
case of optimal allocation of service areas for schools, or optimal patterns of
transportation from origins to destinations. In general, a spatial optimization
problem might find solutions in the form of any augmentation of a GIS
database. From an object-oriented perspective (e.g., Zeiler 1999), this might
mean the creation of a new feature class; the addition or deletion of features
from an existing class; the addition or modification of one or more attributes
of a feature class; the creation of a new association class representing patterns
of interaction between existing origins and destinations; the creation of new
routes that are themselves aggregations of an existing edge feature class, etc.
In this way, the problems formulated as spatial optimizations can be related
directly to the elements of a modern GIS database design. More broadly, we
can see geodesign as transforming an existing database D into a new one D
through some combination of edits.
Spatial optimization provides a useful framework for geodesign, although it
is often far too simplistic, as the next section explains. Spatial optimization
requires an objective function that reflects the goals of the design, expressed
in numeric form as a function of the solution variables that are available to
be manipulated by the designer. It requires a solution space that is defined
by the solution variables and limited by the constraints. The final design will
occupy one point in the solution space. In geodesign, the solution variables
all can be found in the database, as attributes or geometries of features, or as
attributes of association classes. The user is able to interact with the solution
variables in various ways, such as by using sketch tools to define or edit their
geometries, or using the keyboard to define or edit their attributes.
B i g - D a nD s m a l l -D De s i g n
Spatial optimization often is seen as a task to be performed by a machine
with no human interventionas a fully automated edit of a database. Once
the objectives and constraints are formulated, and the data are assembled,
the machine is allowed to take over, producing a solution that by definition
represents the best possible decision. It is often argued that such formal
procedures provide a vast improvement over the messy, intuitive process of
more traditional decision making. Disagreements between stakeholders over
the objectives and constraints, or over the weights to be applied to different
factors, can be handled through a variety of equally rigorous and mechanical
multi-criteria problem formulations (Thill 1999). However, courts have
sometimes held that a solution can be unacceptable against certain criteria,
such as racial bias, even though the objective function and constraints
included no such bias. Moreover, it may simply be naive to believe that
human rationality, in the form of rigorously formulated optimization
problems, can ever replace the messy nature of politics. Instead, spatial
optimization is better seen as a collaboration between human and machine,
The user is Able
To iNTerACT wiTh
The soluTioN
vAriAbles iN
vArious wAys,
suCh As by usiNg
skeTCh Tools To
deFiNe or ediT
Their geomeTries,
or usiNg The
keyboArd To
deFiNe or ediT
Their ATTribuTes
Cartographic Perspectives, Number 66, Fall 2010
Article Title Author Name(s) | 59
in which the machines role is simply to perform the calculations and
iterations that humans find tediouswith the human still firmly in control.
This argument provides a useful basis for distinguishing between two visions
of the design process. Small-d design takes a simplified viewdesign
consists of the formulation of an optimization problem with objectives and
constraints, the collection of data, the execution of a search for the optimum
solution, and its implementation. In this somewhat naive and simplistic
view, implementation is seen as inevitable, because all participants agreed
on the objectives and must therefore accept the result. Small-d design
most commonly is associated with the disciplines of operations research,
engineering, and management science.
Big-D Design sees the process as complicated by disagreements among
stakeholders, difficulties in deciding what is optimal, feedback loops
that modify objectives, constraints, and data as the process proceeds, and
uncertainties about implementation. Figure 1, taken from the work of
Steinitz (1990; Steinitz et al. 2003), structures Design as a sequence of six
Figure 1. A six-stage framework for the design process, with models at each stage (Courtesy of Carl steinitz).
60 | Article Title Author Name(s)
Cartographic Perspectives, Number 66, Fall 2010
stages with iterative feedbacksand similar schemata can be found in other
sources. Each of these stages might be formalized as a model and supported
by computational tools. Big-D Design most commonly is associated with
the disciplines of landscape architecture and planning. As the dominant
paradigm of geodesign, big-D Designrather than small-d designwill be
implied whenever the term design is used in the remainder of this paper.
The problem of conservation planning provides a useful illustration of the
difference between design and Design. Conservation planning seeks to
acquire a set of conservation areas in order to best preserve one or more
biological species. A set of models is constructed from empirical data
to predict the ability of a given parcel of land to support a given species.
A spatial optimization problem is then formulated, seeking the best
combination of land acquisitions to provide a sustainable population of the
target species (Hof and Bevers 2002). Issues such as the connectedness of
parcels are important to allow for interactions between breeding populations.
The results can be expressed in the form of a new attribute of the land-
parcel feature class, denoting whether or not each land parcel is targeted for
acquisition. Thorne, Cameron, and Quinn (2006) provide an example plan
for land acquisitions in Southern California to preserve the mountain lion.
However, it is naive to believe that the publication of such a plan will have
no impact on the market for land, or on the attitudes of landowners. Instead,
it commonly creates a strong and sustained reaction among the potentially
affected landowners. Moreover, parcels inevitably will be acquired over an
extended period of time, and it is likely that some of the optimal set will
prove impossible to acquire, and will be replaced by alternative near-optimal
parcels. In principle, each replacement affects the optimality of the entire
solution, so the problem needs to be re-solved after every acquisition. In
reality, then, the simple spatial optimization problem (design) is embedded
in a much more complex process (Design) that is characterized by large
amounts of uncertainty. Gallo (2007) shows how important it can be to
avoid publishing a single, deterministic optimum solution, and instead
suggests focusing on relative priorities expressed in probabilistic terms.
ge oDe s i g n a nD c a r t o g r a p h y
The display of geographic information in map form often is seen as an
indispensable part of any geodesign process. Geodesign is by definition
about geographic space, and Dangermonds definition quoted earlier points
directly to cartography and the role of the computer as transforming
an informal sketch into an element of a formal database. One of the
achievements of GIS over the past 45 years has been the development of
an integrated theory of geographic data representation, in other words, of a
formal model of phenomena distributed over the surface and near-surface
of the Earth. It includes discrete objects and continuous fields; points, lines,
areas, and volumes; approaches to the representation of time; and solutions
to the problem of representing flows and interactions (Goodchild, Yuan,
and Cova 2007). GIS has progressed substantially beyond the earlier map
The disPlAy oF
geogrAPhiC
iNFormATioN iN
mAP Form is oFTeN
seeN As AN
iNdisPeNsAble PArT
oF ANy geodesigN
ProCess
Cartographic Perspectives, Number 66, Fall 2010
Article Title Author Name(s) | 61
CArTogrAPhy is
A useFul PArT oF
geodesigN, buT
NoT All AsPeCTs
oF geodesigN
Are iNhereNTly
CArTogrAPhiC
metaphor, when a GIS was viewed informally as a computer containing
maps (Goodchild 1988). Animation, for example, is now almost routine in
computerized displays, but was impossible as long as maps were confined to
analog form on paper.
A two-dimensional display of geographic data, with the defining dimensions
of the display representing (mapping in its mathematical sense) the spatial
dimensions of the data, is a powerful way of showing the user what is present
at every location within the extent of the display. Every point on a paper map
can be printed with any color, and similarly every pixel on a computer display
can be programmed to display any color. The visual impression of linear
features is created by using a similar color along a linear sequence of points
or pixels, and similarly an area is visualized by displaying its boundary, or by
filling it with a uniform color or pattern. Annotation is communicated by
linking points or pixels into the form of characters.
Nevertheless, it has always been difficult to use this approach to display
geographic information that concerns points taken two at a timein other
words, relationships or interactions between mapped features (Takeyama
and Couclelis 1997). It is difficult, for example, to label a feature on a map
according to the several names given to it by the inhabitants of neighboring
areas, or to show flows of migrants or telephone calls. Such flows occur
between pairs of features (origins and destinations), are not independent
properties of either, and therefore cannot be displayed by symbolizing either
feature alone, or even in combination. Lines might be drawn to connect
origins and destinations, and appropriately symbolized, but in many cases
the actual path of flow is not known (Glennon 2010), and a large number
of such lines can render the map unreadable. In the previous section, this
type of information was characterized as an association class in the object-
oriented paradigm. In short, while the results of any spatial optimization
can be regarded as a modification of a database, not all such modifications
are equally easily visualized cartographically. Sketch is an important way of
communicating simple geographic features between user and GIS, and other
important kinds of input can also be captured through interaction between
the user and a map display. More broadly, cartography is a useful part of
geodesign, but not all aspects of geodesign are inherently cartographic.
T H E MC H A R G V I S I O N
Reference has already been made to the early days of GIS and the
importance of design based on multiple layers of input. McHargs vision for
his school of landscape architecture at the University of Pennsylvania used
the stack of layers as a metaphor for the organization of the school (McHarg
1996). Each layer corresponded to one discipline whose subject matter was
important to landscape design, including ecology, hydrology, and geology.
Overlaying the layers symbolized the simultaneous attention that needed to
be paid to each of these as a plan was developed. Each layer would be shaded
according to the weight to be assigned to the corresponding disciplines
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issues, and the relevant factors present at each point.
This is only one aspect of McHargs contribution, of course, but it is
emphasized here because of the way it links design and GIS, and thus
relates to the topic of this paper. Suppose, for example, that the impact of
a proposed pipeline at location x is determined to be ze(x) per unit area,
when measured from the perspective of ecology. Similarly, the impact of the
pipeline at x from the perspective of hydrology might be zh(x) per unit area,
and the economic cost of acquiring the necessary land might be zc(x). The
three measures are incommensurate, of course, so weights must be assigned
to reduce them to a common metric, and to rate their relative importance.
Define these weights as we, wh, and wc respectively. Then the problem can
be formulated as finding a route such that the total weighted cost along the
route is minimized. If S denotes the solution set, that is, the set of points
along the route, then the task is to minimize:
Z
=
x
S
[
zw
e
e
( )
x
+
zw
h
h
( )
x
+
zw
c
c
]
( )
x
In the analog method described in Design with Nature (McHarg 1969), both
w and z must be captured by the darkness of the corresponding layer at point
x, and the optical process of overlaying layers replaces the summation in the
equation by a multiplication. In reality, of course, the kind of rigor exhibited
in the equation was never intended to be imposed in the analog method, but
the more formal GIS overlay process forces the user to address all of these
issues explicitly. For example, the weights w might be assigned using Saatys
Analytical Hierarchy Process (AHP), or a variety of other methods that are
described in the standard texts on multicriteria decision analysis (Malczewski
and Rinner 2010; Thill 1999). Similarly, it is common to address the apples-
and-oranges issue of non-commensurate variables by normalizing each to
the range 0 to 1. But since the observed range depends on the exact extent of
the study area, there are obvious logical flaws in this practice.
Despite the informality of the analog model, McHarg clearly intended his
design process to be informed by science, and achieved this by constructing
each layer according to the knowledge base of the corresponding discipline.
Moreover, the school included representatives of each of those disciplines on
its staff, forcing intensive engagement and interaction. This is a very different
approach from that commonly followed in most universities, where the
science disciplines are separated from the design disciplines, often across the
boundaries between colleges or faculties. One of the underlying themes of
geodesign is its potential to reduce that separation.
McHargs vision is now more than four decades old, so it makes sense to ask
whether and how it should be updated to the present. Enormous advances
have been made in the disciplines that study social and environmental
processes on the Earths surface, and an argument can clearly be made for
including all of them to the extent that they are relevant to a specific design
question. But in addition, we know far more now than we did then about the
Cartographic Perspectives, Number 66, Fall 2010
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process of decision making, and particularly about the role of uncertainty.
Thus, it would seem important to include decision scientists and statisticians
in the mix, especially spatial statisticians. We also would need to include
the computer scientists and information scientists who address issues of
representation and develop the algorithms needed to implement scientific
knowledgeespecially geographic information scientistsand the experts
in remote sensing and sensor networks who address issues of spatial data
acquisition. We also would need to include the cartographers and specialists
in spatial cognition who address human factors in the interactions between
designers and tools, and the social psychologists who study processes of
group interaction.
C O M P U TAT I O N A L S U P P O R T F O R G E O D E S I G N
In the complex process represented by Figure 1, geodesign can be partitioned
into a series of stages, each underlain by a model and each supported by
computational tools. This is very different from the conceptualization of
small-d design, in which the entire process occurs in a single stage, and in
which a large proportion of control is surrendered to the computational
system and its task of finding the best solution. The field of spatial decision
support systems (SDSS) has long addressed the kinds of computational tools
needed to support design decisions, and has accumulated a substantial
literature (Leung 1997; Sugumaran and Degroote 2010). Li and her
collaborators have recently constructed a very substantial collection of Web
resources (http://www.institute.redlands.edu/sds), including an ontology
of SDSS, in an effort to address the varying use of terms and to clarify the
fields relationship with other cognate fields.
What then is the relationship between SDSS and geodesign? SDSS has its
roots in the early 1990s (Densham and Goodchild 1990), and in a desire
to apply GIS tools to a host of problems of spatial optimization. SDSS has
always had a strong science base, so one might see geodesign as an effort to
expand SDSS to include some of the design problems that have traditionally
made less use of scientific knowledge to simulate the effects and impacts
of plans. In other words, traditional SDSS may best be seen as a subset of
geodesign, if any distinction is needed.
Reference was made earlier to the notion that there are two areas where
geodesign tools need further development:
sk e t c h t o o l s
The first key area of support for geodesign is sketch, or the ability of the user
to create informal renderings of points, lines, and areas in geographic space,
and to have the computational system capture, formalize, and store these.
ESRIs ArcSketch already offers some of these capabilities, and Googles
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iN CoNveNTioNAl
ediTiNg, The user
seeks To APProximATe
A TRUTH, As exPressed
PerhAPs by A sourCe
doCumeNT, whereAs
No suCh TruTh exisTs
iN The CAse oF skeTCh,
whiCh is iNhereNTly
vAgue
SketchUp extends them to the third spatial dimension.
In essence, sketch tools would allow the user to edit a GIS database by
inserting new point, line, and area features. These might be added to existing
feature classes or might be captured as entirely new classes. For example, a
user seeking the best locations for a number of new retail stores to add to
an existing chain might sketch potential locations. The system then might
evaluate these locations based on a predictive model of store sales, or use
them as the starting points for an optimal search procedure. From this
perspective, sketch tools are augmentations of existing GIS database editing
functions. But the emphasis is rather different; in conventional editing, the
user seeks to approximate a truth, as expressed perhaps by a source document,
whereas no such truth exists in the case of sketch, which is inherently vague.
si m u l at i o n t o o l s
The second area is simulation, or the examination of design scenarios
by simulating their impacts based on sound scientific knowledge. For
example, the impacts of a proposed new highway might be examined by
simulating its effects on the pattern of traffic in the surrounding area; on
the downstream effects on local hydrology; and on noise and atmospheric
pollution. Calibrated models exist for each of these sets of impacts as a result
of basic scientific research. Moreover, in many areas large numbers of models
exist, based on different sets of assumptions, requiring different inputs,
and yielding different answers. One of the most valuable outputs of a GIS
simulation may lie in the uncertainties associated with predictions, based on
uncertainties within each model and on variation across models.
Many successful efforts have been made to integrate models of social
and environmental processes into GIS, and the results are described in a
substantial literature (Goodchild, Parks, and Steyaert 1993; Skidmore 2002).
Many models are difficult to integrate with GIS and with other models
because of lack of standards governing data formats, and there is also a
need for greater standardization in the languages in which model software
is written. Both of these factors impede the goals of geodesign, because
they make it difficult to implement many models as simple functions of a
geodesign software environment.
More specifically, research is needed to address two issues of major
importance:
1. Models need to be encapsulated easily within GIS, so that they can be
executed and the results analyzed within the workflow of a geodesign
process. This implies that data inputs and outputs need to follow GIS data
format standards so they can be integrated readily with GIS databases,
and that model parameters be exposed to the user through a GIS
interface.
2. Models need to be written in a common language, so that their
component parts can be reassembled and reused readily. In practice,
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Article Title Author Name(s) | 65
models are commonly written in a range of computing environments,
from source languages such as C++ to scripting languages such as Python.
Efforts to develop a common, uniform language for GIS have made only
limited progress in the past (e.g., the Map Algebra of Tomlin 1990),
though van Deursens scripting language for PCRaster (van Deursen
1995) offers a comprehensive solution at least for simulations over a
cellular landscape. A comprehensive solution to this problem would be a
major contribution to the goals of geodesign.
Behind this need for a common language lies a much more fundamental
problem, that of defining a standard set of GIS operations. While various
taxonomies have been published, it is regrettably true that after 45 years of
GIS development there exists no standard set that is defined on a rigorous
conceptual basis. Instead, the sets of functions offered by popular GIS
packages, such as the ArcToolbox, are the result of a haphazard historical
process of development. There are no universal standards and no rigorous
concept of granularity, making it difficult to discover functions offered on the
Web and undermining the entire concept of service-oriented architecture. A
conceptual framework for the structuring of GIS functionality would be an
enormously valuable contribution, enabling a new level of interoperability
across the GIS field.
D I S C U S S I O N A N D C O N C L U S I O N
It will be obvious from the preceding sections that geodesign is not new, but
instead represents a re-examination and perhaps a repurposing of a number
of established fields. In the case of GIS, this re-examination is prompted by
a perceived lack of attention to the use of GIS in design, and to its potential
role in improving the geographic world. In the case of spatial optimization, it
is prompted by the perception that design problems are more complex than
simple mathematical formulations, and that the political process of decision
making is more complex than the execution of a single optimization. In the
case of landscape architecture, it is prompted by the notion that science can
play a much stronger role in informing important decisions over the use of
land, and that GIS is a valuable platform for integrating scientific knowledge
into the design process.
The design of tools is driven by a constant tension between the specific and
the general: between the scale economies that result from a one-size-fits-all
solution, and the speed with which a targeted solution to a specific problem
can be constructed. In the 1970s, GIS emerged as a generic solution to a set
of requirements that ranged from cartographic editing to land-use planning
and the administration of the census. Today, a suite of integrated geodesign
tools may emerge from the realization that a host of geographic design
problems share a common structure, and rely on access to a common GIS
database. Just as with GIS, the attendant economies of scale in software
TodAy, A suiTe
oF iNTegrATed
geodesigN Tools
mAy emerge From
The reAlizATioN
ThAT A hosT oF
geogrAPhiC
desigN Problems
shAre A CommoN
sTruCTure, ANd
rely oN ACCess
To A CommoN gis
dATAbAse
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Now more ThAN
ever, we seNse The
Need For eFFeCTive
Tools ThAT CAN
helP us To eNsure A
desirAble FuTure For
The PlANeT, ANd gis
CleArly CoNTAiNs
The FouNdATioN For
suCh Tools
production, training, and documentation would be enormous.
For that to happen, however, several issues have to be resolved. Two have
already been mentioned: the lack of interoperability between existing model
codes, and the lack of a language within which an integrated vision of
reusable codes could be implemented. In addition, however, it is important to
address the question of how a suitable computing environment, once defined,
might be widely adopted. Several successful models can be found in the
history of GIS:
1. The commercial software route. Commercial software developers have the
development staffs and the necessary mechanisms for promotion, training,
and support to turn a design into a widely adopted reality. An advisory
group of geodesigners might define the framework, and ensure that it was
successfully implemented in tools.
2. The open-source route. GRASS was an early and highly successful effort
to develop a comprehensive GIS for environmental modeling, based
on open-source code and a network of researchers who added routines
within a loosely defined set of standards. The role of the US Army Corps
of Engineers in providing the initial foundation was critical, and suggests
that a suitable strategy would be to obtain a major grant from a funding
agency to construct the framework and to build the initial community of
contributors and users.
3. The research center route. GeoDa (http://geodacenter.asu.edu) is another
example of a highly successful package of tools, in this case addressing the
needs of social scientists for easy-to-use software for spatial analysis. It
was developed under a major center grant from the US National Science
Foundation, which funded not only the code but also tutorials and
workshops that publicized its applications.
Design was clearly an early objective of GIS, but as argued earlier, it tended
to lose its centrality as GIS evolved to serve more lucrative and immediate
markets. Now more than ever, we sense the need for effective tools that can
help us to ensure a desirable future for the planet, and GIS clearly contains
the foundation for such tools. The concept of geodesign presents a simple
banner for a renewed effort to emphasize the value of cartography and GIS
as tools for improving and sustaining the surface and near-surface of the
Earth.
ACkN O W L E D G E M E N T
This paper has benefited from numerous discussions over the past few
months, most notably with Bill Miller (ESRI), Naicong Li (Redlands
Institute), and Carl Steinitz (Harvard University). The opinions and
conclusions expressed are entirely those of the author, however.
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Article Title Author Name(s) | 67
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