A Spatial Perspective
Integrating GIS into the decision-making process

As individuals, we make decisions based on geography every day. Some decisions are simple and have short-term consequences such as "Where will I eat lunch today?" Other decisions such as "Where will I live?" have a greater and more lasting impact on our lives.

New computing platforms, such as Web GIS, have contributed to the expansion of GIS and its incorporation into decision-support systems.

Companies, government agencies, and other organizations make decisions that have far-reaching effects, and geography affects these decisions as well. Where a new store is built in relation to potential customers may determine its success or failure. Land-use decisions can be instrumental in making a community a desirable place to live.

Applying Geographic Knowledge

Incorporating geography into the decision-making process for organizations provides insights that will affect which approach is chosen and the outcome that is obtained. The value of using a geographic framework for problem solving increases as the scale and complexity of the problem increase. Challenges currently faced by society—such as global warming, resource shortages, and loss of biodiversity—require considering competing interests and interdependencies. The choices made will have profound and long-term consequences.

Using geography as a framework for understanding and managing our relationship with the world has been called the geographic approach. While it can be more effectively applied digitally, the development of the geographic approach predates computers and was popularized by Ian McHarg in his book, Design with Nature, published in 1969. With computers, large volumes of data can be processed and the use of the geographic approach expanded to use with problems that were previously precluded from consideration.

A Better Approach

Improving decision making by applying the geographic approach is one of the most compelling reasons to develop a GIS, particularly at the enterprise level and beyond. Traditional (nonspatial) decision-making processes typically involve six basic steps.

1. Identify the problem.
2. Gather information relevant to that problem.
3. Develop alternative solutions.
4. Evaluate these solutions.
5. Decide which solution best solves the problem.
6. Implement that solution and determine its effectiveness.

When applied to the real world, these steps are not purely sequential but are typically an iterative process. For example, gathering information relating to the problem identified may refine perceptions of the problem and reveal the need for additional or different kinds of information. Similarly, as alternative solutions are identified and considered, information may be reconsidered.

Dirk Kempthorne, the secretary of United States Department of the Interior, accepting the Making a Difference Award.

Applying geography improves the decision-making process by addressing problems and evaluating proposed solutions implemented in a holistic, comprehensive, systematic, analytic, and visual manner. GIS furnishes digital tools for abstracting and organizing data, modeling geographic processes, and visualizing information that enable leaders to make meaningful and effective decisions. With GIS, the analysis of problems can have greater depth as many layers of data relating to the physical and cultural world can be considered together.

Favorable Factors

Developments in data collection systems, GIS technology, geographic information science, and computing in the last decade have made the application of GIS to the decision-making process more feasible and attractive.

Volumes of data, now collected by sensor systems, are being more effectively analyzed using the data integration and management capabilities of GIS. The Hydrologic Information System (HIS), created by the Consortium of Universities for the Advancement of Hydrologic Science, Inc., with funding from the United States National Science Foundation, organizes and makes available water observation data collected by scientists working on many different projects. This is accomplished through integrating observation data with GIS data, which provides the spatial context of watersheds, aquifers, and stream networks.

The increase in remotely sensed data collected and its integration in a circular GIS workflow incorporating the Image extension for ArcGIS Server has greatly increased the availability of this valuable and timely data source for areas as large as countries or regions. These developments make it possible for decision makers to have a much broader view of phenomena.

With enhanced geoprocessing tools, GIS professionals can create new information from these data sources. Modeling data supplies a method for asking spatial questions that explore the relationships between different factors. With the cartographic tools in GIS, this information can be displayed in a manner that communicates in a clear and compelling fashion not only to decision makers but also to the public.

More powerful systems and the migration to new computing platforms in the last decade have also contributed to the expansion of GIS and its incorporation into decision-support systems. Enterprise technology and interenterprise systems now manage more information, support more applications, and provide more rapid access to information.

The ascent of server GIS has generated applications that influence decision making from the organizational to the individual level: the growth of mashups; the popularity of consumer information delivered as a map on a phone; the availability of substantial prepackaged datasets such as the Esri Data Appliance; and the delivery of globes, maps, and services by ArcGIS Online. Each year, people attending GIS Day for the first time are surprised to learn how many ways GIS touches their lives every day.

Tackling Big Problems

An article in this issue, "Carbon Nation—Automated GIS process is creating a snapshot of biomass and carbon in U.S. forests," illustrates how GIS is being used to address global climate change. A team at the Woods Hole Research Center is exploring the connection between the carbon cycle and land cover through the creation of the National Biomass and Carbon Dataset for the year 2000.

The need to manage water resources in a manner that ensures adequate freshwater supplies is a worldwide concern. The GIS-based tools developed for a program that assists water resource managers in West African countries is the subject of another article, "Visualization, Interpretation, and Evaluation—Building a multitemporal SDSS scenario viewer with ArcGIS Engine." A joint venture by the universities of Cologne and Bonn, Germany, has created a platform-independent tool that helps decision makers assess analyses that incorporate spatial and other data sources and forecast the effects of global climate change on water resources in two areas of West Africa.

Another article, "Modeling Better Decisions—Land evaluation and site assessment enhanced with GIS," explains how a proven decision-making methodology was enhanced by adding GIS. The authors describe how a land-use decision-making system was made more accessible, reliable, and flexible by incorporating ArcGIS and ModelBuilder into the process.

In each case, GIS allows decision makers to consider not only economic and political factors but also ecological and cultural ones. For example, it is difficult to discern the relationships between factors such as population density and freshwater supplies by just looking at a table. However, thematically mapping this data can make relationships apparent. Viewed in a geographic framework, dependencies and interactions are more apparent and the trade-offs between a variety of possible solutions can be modeled and evaluated.

Supporting Better Decisions

GIS brings both depth and scope to the decision-making process. In accepting the Making a Difference Award at this year's Esri International User Conference, United States Department of the Interior Secretary Dirk Kempthorne described a future in which the decision-making process benefits from the geographic approach.

"My vision for the future is that with the click of a mouse, decision makers and land managers from Washington, D.C., to Kampala, Uganda, from San Diego, California, to Johannesburg, South Africa, will have access to maps that Lewis and Clark could never have imagined," said Kempthorne. "Maps include up-to-date imagery of the landscape—maps that overlay population data, land use, wildlife habitat, and other forms of geographic information—to paint a more complete picture of our planet."