|
Introduction – The
GIS Evolution |
Map
Analysis book/CD |
Early
GIS Technology and Its Expression — traces the early phases of GIS technology (Computer Mapping, Spatial
Database Management and Map Analysis/Modeling)
Contemporary
GIS and Future Directions — discusses contemporary GIS and probable future directions (Multimedia
Mapping and Spatial Reasoning/Dialog)
Further Reading
— nine additional sections organized into three parts
<Click here>
for a printer-friendly version of this
topic (.pdf).
(Back to Book III Table of Contents)
______________________________
Early GIS Technology and Its Expression
(GeoWorld, October 2006)
Considerable
changes in both expectations and capabilities have taken place since GIS’s birth
in the late 1960s. In this and a few
subsequent columns, I hope to share a brief history and a probable future of
this rapidly maturing field as viewed from grey-beard experience from over 30
years involvement in the field (see Author’s Note).
Overview
Information has always been the cornerstone of effective decisions. Spatial information is particularly complex
as it requires two descriptors—Where is What. For thousands of years the link between the
two descriptors has been the traditional, manually drafted map involving pens,
rub-on shading, rulers, planimeters, dot grids, and acetate sheets. Its historical use was for navigation through
unfamiliar terrain and seas, emphasizing the accurate location of physical
features.
More recently, analysis of mapped data has become an important part of
understanding and managing geographic space.
This new perspective marks a turning point in the use of maps from one
emphasizing physical description of geographic space, to one of interpreting
mapped data, combining map layers and finally, to spatially characterizing and
communicating complex spatial relationships.
This movement from “where is what” (descriptive) to "so what and
why" (prescriptive) has set the stage for entirely new geospatial concepts
and tools.
Since
the 1960's, the decision-making process has become increasingly quantitative,
and mathematical models have become commonplace. Prior to the computerized map, most spatial
analyses were severely limited by their manual processing procedures. The computer has provided the means for both
efficient handling of voluminous data and effective spatial analysis
capabilities. From this perspective, all
geographic information systems are rooted in the digital nature of the
computerized map.
The coining of the term Geographic Information Systems reinforces this movement
from maps as images to mapped data. In
fact, information is GIS's middle name.
Of course, there have been other, more descriptive definitions of the
acronym, such as "Gee It's Stupid," or "Guessing Is
Simpler," or my personal favorite, "Guaranteed Income Stream."
Computer Mapping (1970s, Beginning
Years)
The early 1970's saw computer mapping automate map drafting. The points,
lines and areas defining geographic features on a map are represented as an
organized set of X, Y coordinates. These data drive pen plotters that can
rapidly redraw the connections at a variety of colors, scales, and projections
with the map image, itself, as the focus of the processing.
The
pioneering work during this period established many of the underlying concepts
and procedures of modern GIS technology. An obvious advantage with computer
mapping is the ability to change a portion of a map and quickly redraft the
entire area. Updates to resource maps which could take weeks, such as a forest
fire burn, can be done in a few hours. The less obvious advantage is the
radical change in the format of mapped data— from analog inked lines on paper,
to digital values stored on disk.
Spatial Database Management (1980s,
Adolescent Years)
During 1980's, the change in data format and computer environment was
exploited. Spatial database management systems were developed that
linked computer mapping capabilities with traditional database management
capabilities. In these systems,
identification numbers are assigned to each geographic feature, such as a
timber harvest unit or ownership parcel.
For example, a user is able to point to any location on a map and
instantly retrieve information about that location. Alternatively, a user can specify a set of
conditions, such as a specific forest and soil combination, then
direct the results of the geographic search to be displayed as a map.
Early
in the development of GIS, two alternative data structures for encoding maps
were debated. The vector data model closely mimics
the manual drafting process by representing map features (discrete spatial
objects) as a set of lines which, in turn, are stores as a series of X,Y coordinates. An
alternative structure, termed the raster
data model, establishes an imaginary grid over a project area, and
then stores resource information for each cell in the grid (continuous map
surface). The early debate attempted to
determine the universally best structure.
The relative advantages and disadvantages of both were viewed in a
competitive manner that failed to recognize the overall strengths of a GIS
approach encompassing both formats.
By the
mid-1980's, the general consensus within the GIS community was that the nature of
the data and the processing desired determines the appropriate data
structure. This realization of the
duality of mapped data structure had significant impact on geographic
information systems. From one
perspective, maps form sharp boundaries that are best represented as
lines. Property ownership, timber sale
boundaries, and road networks are examples where lines are real and the data
are certain. Other maps, such as soils,
site index, and slope are interpretations of terrain conditions. The placement of lines identifying these
conditions is subject to judgment and broad classification of continuous
spatial distributions. From this
perspective, a sharp boundary implied by a line is artificial and the data itself
is based on probability.
Increasing
demands for mapped data focused attention on data availability, accuracy and
standards, as well as data structure issues.
Hardware vendors continued to improve digitizing equipment, with manual
digitizing tablets giving way to automated scanners at many GIS
facilities. A new industry for map
encoding and database design emerged, as well as a marketplace for the sales of
digital map products. Regional, national
and international organizations began addressing the necessary standards for
digital maps to insure compatibility among systems. This era saw GIS database development move
from project costing to equity investment justification in the development of
corporate databases.
Map Analysis and Modeling (1990s,
Maturing Years)
As GIS continued its evolution, the emphasis turned from descriptive query to
prescriptive analysis of maps. If early
GIS users had to repeatedly overlay several maps on a light-table, an analogous
procedure was developed within the GIS.
Similarly, if repeated distance and bearing calculations were needed,
the GIS system was programmed with a mathematical solution. The result of this effort was GIS
functionality that mimicked the manual procedures in a user's daily activities. The value of these systems was the savings
gained by automating tedious and repetitive operations.
By the
mid-1980's, the bulk of descriptive query operations were available in most GIS
systems and attention turned to a comprehensive theory of map analysis. The dominant feature of this theory is that
spatial information is represented numerically, rather than in analog fashion
as inked lines on a map. These digital
maps are frequently conceptualized as a set of "floating maps" with a
common registration, allowing the computer to "look" down and across
the stack of digital maps. The spatial
relationships of the data can be summarized (database queries) or
mathematically manipulated (analytic processing). Because of the analog nature of traditional
map sheets, manual analytic techniques are limited in their quantitative
processing. Digital representation, on
the other hand, makes a wealth of quantitative (as well as qualitative)
processing possible. The application of
this new theory to mapping was revolutionary and its application takes two
forms—spatial statistics and spatial analysis.
Meteorologists
and geophysicists have used spatial
statistics for decades to characterize the geographic distribution,
or pattern, of mapped data. The
statistics describe the spatial variation in the data, rather than assuming a
typical response is everywhere. For
example, field measurements of snow depth can be made at several plots within a
watershed. Traditionally, these data are
analyzed for a single value (the average depth) to characterize an entire
watershed. Spatial statistics, on the
other hand, uses both the location and the measurements at sample locations to
generate a map of relative snow depth throughout the watershed. This numeric-based processing is a direct
extension of traditional non-spatial statistics.
Spatial analysis applications, on the other hand, involve
context-based processing. For example,
forester’s can characterize timber supply by considering the relative skidding
and log-hauling accessibility of harvesting parcels. Wildlife managers can consider
such factors as proximity to roads and relative housing density to map human
activity and incorporate this information into habitat delineation. Land
planners can assess the visual exposure of alternative sites for a facility to
sensitive viewing locations, such as roads and scenic overlooks.
Spatial
mathematics has evolved similar to spatial statistics by extending conventional
concepts. This "map algebra"
uses sequential processing of spatial operators to perform complex map
analyses. It is similar to traditional
algebra in which primitive operations (e.g., add, subtract, exponentiation) are logically
sequenced on variables to form equations.
However in map algebra, entire maps composed of thousands or millions of
numbers represent the variables of the spatial equation.
Most of
the traditional mathematical capabilities, plus an extensive set of advanced
map processing operations, are available in modern GIS packages. You can add, subtract, multiply, divide, exponentiation, root, log, cosine, differentiate
and even integrate maps. After all, maps
in a GIS are just organized sets of numbers.
However, with map-ematics, the spatial
coincidence and juxtaposition of values among and within maps create new
operations, such as effective distance, optimal path routing, visual exposure
density and landscape diversity, shape and pattern. These new tools and
modeling approach to spatial information combine to extend record-keeping
systems and decision-making models into effective decision support systems.
In many
ways, GIS is “as different as it is similar” to traditional mapping. Its early expressions simply automated
existing capabilities but in its modern form it challenges the very nature and
utility of maps. The next section
focuses on contemporary GIS expressions (2010s) and its probable future
directions.
Contemporary
GIS and Future Directions
(GeoWorld, November 2006)
The previous
section focused on early GIS technology and its expressions as three
evolutionary phases— Computer Mapping (70s), Spatial Database Management (80s)
and Map Analysis/Modeling (90s). These
efforts established the underlying concepts, structures and tools supporting
modern geotechnology. What is radically
different today is the broad adoption of GIS and its new map forms.
In the
early years, GIS was considered the domain of a relatively few cloistered
techno-geeks “down the hall and to the right.” Today, it is on everyone’s desk, PDA and even
cell phone. In just three decades it has
evolved from an emerging science to a fabric of society that depends on its
products from getting driving directions to sharing interactive maps of the
family vacation.
Multimedia Mapping (2010s, Full Circle)
In
fact, the U.S. Department of Labor has designated Geotechnology as one of the
three “mega-technologies” of the 21st century—right up there with
Nanotechnology and Biotechnology. This
broad acceptance and impact is in large part the result of the general wave of
computer pervasiveness in modern society.
We expect information to be just a click away and spatial information is
no exception.
However,
societal acceptance also is the result of the new map forms and processing
environments. Flagship GIS systems, once
heralded as “toolboxes,” are giving way to web services and tailored
application solutions. There is growing
number of websites with extensive sets of map layers that enable users to mix
and match their own custom views. Data
exchange and interoperability standards are taking
hold to extend this flexibility to multiple nodes on the web, with some data
from here, analytic tools from there and display capabilities from over
there. The results are high-level
applications that speak in a user’s idiom (not GIS-speak) and hide the
complexity of data manipulation and obscure command sequences. In this new environment, the user focuses on
the spatial logic of a solution and is hardly aware that GIS even is involved.
Another
characteristic of the new processing environment is the full integration the
global positioning system and remote sensing imagery with GIS. GPS and the digital map bring geographic
positioning to the palm of your hand.
Toggling on and off an aerial photograph provides reality as a backdrop
to GIS summarized and modeled information.
Add ancillary systems, such as robotics, to the mix and new automated
procedures for data collection and on-the-fly applications arise.
In
addition to the changes in the processing environment, contemporary maps have
radical new forms of display beyond the historical 2D planimetric paper
map. Today, one expects to be able to
drape spatial information on a 3D view of the terrain. Virtual reality can transform the information
from pastel polygons to rendered objects of trees, lakes and buildings for near
photographic realism. Embedded
hyperlinks access actual photos, video, audio, text and data associated with
map locations. Immersive imaging enables
the user to interactively pan and zoom in all directions within a display.
4D GIS
(XYZ and time) is the next major frontier.
Currently, time is handled as a series of stored map layers that can be
animated to view changes on the landscape.
Add predictive modeling to the mix and proposed management actions
(e.g., timber harvesting and subsequent vegetation growth) can be introduced to
look into the future. Tomorrow’s data
structures will accommodate time as a stored dimension and completely change
the conventional mapping paradigm.
Spatial Reasoning and Dialog (Future, Communicating Perceptions)
The
future also will build on the cognitive basis, as well as the databases, of GIS
technology. Information systems are at a
threshold that is pushing well beyond mapping, management, modeling, and
multimedia to spatial reasoning and dialogue.
In the past, analytical models have focused on management options that
are technically optimal— the scientific solution. Yet in reality, there is another set of perspectives
that must be considered— the social solution.
It is this final sieve of management alternatives that most often
confounds geographic-based decisions. It
uses elusive measures, such as human values, attitudes, beliefs, judgment,
trust and understanding. These are not
the usual quantitative measures amenable to computer algorithms and traditional
decision-making models.
The step from technically feasible to socially acceptable options is not so
much increased scientific and econometric modeling, as it is
communication. Basic to effective
communication is involvement of interested parties throughout the decision
process. This new participatory
environment has two main elements— consensus building and conflict resolution.
Consensus Building involves
technically-driven communication and occurs during the alternative formulation
phase. It involves a specialist's
translation of various considerations raised by a decision team into a spatial
model. Once completed, the model is
executed under a wide variety of conditions and the differences in outcome are
noted.
From this perspective, an individual map is not the objective. It is how maps change as the different
scenarios are tried that becomes information.
"What if avoidance of visual exposure is more important than
avoidance of steep slopes in siting a new electric transmission line? Where does the proposed route change, if at
all?" What if slope is more
important? Answers to these analytical
queries (scenarios) focus attention on the effects of differing
perspectives. Often, seemingly divergent
philosophical views result in only slightly different map views. This realization, coupled with active
involvement in the decision process, can lead to group consensus.
However, if consensus is not obtained, mechanisms for resolving conflict come
into play. Conflict Resolution extends the Buffalo Springfield’s lyrics,
"nobody is right, if everybody is wrong," by seeking an acceptable
management action through the melding of different perspectives. The socially-driven communication occurs
during the decision formulation phase.
It
involves the creation of a "conflicts map" which compares the
outcomes from two or more competing uses.
Each map location is assigned a numeric code describing the actual conflict
of various perspectives. For example, a
parcel might be identified as ideal for a wildlife preserve, a campground and a
timber harvest. As these alternatives
are mutually exclusive, a single use must be assigned. The assignment, however, involves a holistic
perspective which simultaneously considers the assignments of all other
locations in a project area.
Traditional scientific approaches rarely are effective in addressing the
holistic problem of conflict resolution.
Even if a scientific solution is reached, it often is viewed with
suspicion by less technically-versed decision-makers. Modern resource information systems provide
an alternative approach involving human rationalization and tradeoffs.
This
process involves statements like, "If you let me harvest this parcel, I
will let you set aside that one as a wildlife
preserve." The statement is
followed by a persuasive argument and group discussion. The dialogue is far from a mathematical
optimization, but often comes closer to an acceptable decision. It uses the information system to focus
discussion away from broad philosophical positions, to a specific project area
and its unique distribution of conditions and potential uses.
Critical Issues (Future Challenges)
The technical hurdles surrounding GIS have been aggressively tackled over the
past four decades. Comprehensive spatial
databases are taking form, GIS applications are accelerating and even office
automation packages are including a "mapping button." So what is the most pressing issue
confronting GIS in the next millennium?
Calvin,
of the Calvin and Hobbes comic strip, puts it in perspective: "Why waste
time learning, when ignorance is instantaneous?" Why should time be wasted in GIS training and
education? It's just a tool, isn't
it? The users can figure it out for
themselves. They quickly grasped the
operational concepts of the toaster and indoor plumbing. We have been mapping for thousands of years
and it is second nature. GIS technology
just automated the process and made it easier.
Admittedly, this is a bit of an overstatement, but it does set the stage for
GIS's largest hurdle— educating the masses of potential users on what GIS is
(and isn't) and developing spatial reasoning skills. In many respects, GIS technology is not
mapping as usual. The rights, privileges
and responsibilities of interacting with mapped variables are much more
demanding than interactions with traditional maps and spatial records.
At
least as much attention (and ultimately, direct investment) should go into
geospatial application development and training as is given to hardware,
software and database development. Like
the automobile and indoor plumbing, GIS won't be an important technology until
it becomes second nature for both accessing mapped data and translating it into
information for decisions. Much more
attention needs to be focused beyond mapping to that of spatial reasoning, the
"softer," less traditional side of geotechnology.
GIS’s
development has been more evolutionary, than revolutionary. It responds to contemporary needs as much as
it responds to technical breakthroughs.
Planning and management have always required information as the
cornerstone. Early information systems
relied on physical storage of data and manual processing. With the advent of the computer, most of
these data and procedures have been automated.
As a result, the focus of GIS has expanded from descriptive inventories
to entirely new applications involving prescriptive analysis. In this transition, map analysis has become
more quantitative. This wealth of new
processing capabilities provides an opportunity to address complex spatial
issues in entirely new ways.
It is clear that GIS technology has greatly changed our perspective of a
map. It has moved mapping from a
historical role of provider of input, to an active and vital ingredient in the
"thruput" process of decision-making. Today's professional is challenged to
understand this new environment and formulate innovative applications that meet
the complexity and accelerating needs of the twenty-first century.
_____________________
Further Online
Reading: (Chronological
listing posted at www.innovativegis.com/basis/BeyondMappingSeries/)
(Software Design)
GIS Software's Changing Roles
— discusses the evolution of GIS software and identifies
important trends (September 1998)
What Is Object-Oriented Technology
Anyway? — establishes the basic concepts in
object-oriented technology (September 1996)
Spatial Objects—Parse and Parcel of
GIS? — discusses database objects and their map expressions
(October 1996)
Does Anyone Object? — discusses
some concerns of object-oriented GIS (November 1996)
(Virtual Reality and GIS)
Behind the Scenes of Virtual Reality
— discusses the basic considerations and concepts in 3D-object
rendering (June 2000)
How to Rapidly Construct a Virtual
Scene — describes the procedures in generating a
virtual scene from landscape inventory data (July 2000)
How to Represent Changes in a Virtual
Forest — discusses how simulations and
"fly-bys" are used to visualize landscape changes and characteristics
(August 2000)
(Multimedia Mapping)
Capture "Where and When" on
Video-based GIS — describes how
Video Mapping Brings Maps to Life
— describes how video maps are generated and discusses some
applications of video mapping (October 2000)
(Back to Book III Table of Contents)