For example, a person who tackles a problem using numbers, calculations, and probabilities reaches very different conclusions than someone who approaches the same problem using the principles of geography. When making far-reaching decisions that have a significant impact on our environment, the consequences of not taking the geographic approach can be critical.

Geography is the science of our world, describing the physical and cultural patterns and processes of our planet. This science provides humans with awareness of what's going on, predictions of what may happen, and systematic information for planning and decision making.

Geography helps us better understand various spatial phenomena and their interrelationships. For example, the relationships between climate, soils, and topographic slope can help predict agricultural productivity. These understandings can help us become more conscious and aware of the interrelatedness of our world and how our cumulative behavior is affecting the evolution of the planet.

GIS extends the power of geography by providing digital tools that abstract and organize geospatial data, model geographic processes, and visualize this data and these models with advanced computer techniques.

Applying Geographic Knowledge

GIS is helping us apply geographic knowledge to a host of challenges, ranging from making organizations more efficient to supporting location decisions that require examining many geographic factors.

For example, when selecting the route for a new highway, GIS and the geographic approach can be used to consider the physical and human factors that should guide its layout and design: the environment, existing land use, terrain, and social impacts, as well as engineering constraints and costs.

Considering all these factors can be overwhelming, particularly when trying to make complex trade-offs. This is where the use of GIS is particularly valuable.

Origins

A key method of the geographic approach involves integrating many factors on a map and interpreting their meaning in a holistic way by means of map overlay. This classical method was popularized by Ian McHarg in his book Design with Nature in the 1960s.

The advent of GIS allowed planners to replace plastic overlay maps with digital overlays that could be integrated and modeled using various quantitative spatial analysis tools. These weighted overlays combine the various factors of importance based on scientific or human judgments related to a particular decision. An example might be a map showing the relative suitability of a landscape for locating a new facility or for a particular land use.

Today, biologists use this type of approach for modeling the geography of natural habitats. Similarly, hydrologists model flooding and flood risks, sociologists model neighborhoods and social behavior, and land-use planners regularly combine these types of models to better understand how to design strategies for creating the future.

This approach is being used in many other fields: by the military for cross-country mobility; by resource planners for forest management, mining, and petroleum extraction; and by city planners in organizing and managing urban growth. It's being used in disaster preparedness planning and response to fires, earthquakes, hurricanes, and floods. This approach is helping organizations provide humanitarian assistance during famines and social conflicts. Utilities are applying the geographic approach to planning, engineering, and managing infrastructure networks, and businesses use it to select the best locations, market their products, manage territories, efficiently route vehicles, and make their business more efficient. All these applications deliver huge benefits to organizations and to the rest of us.