GIS: The What and Why

I've found that the most common response to the news that I'll be studying GIS this fall is "What's GIS?" It's a frustrating question for me, since I usually stumble my way through the explanation -- and likely frustrating for the listener too who has to suffer through the stuttering. The problem isn't a poor grasp of the subject matter, but having to decide what definition of a complex topic to choose, how to tailor it to the level of understanding of whoever is asking, how much time I actually want to spend explaining it and how thorough an explanation they really want to hear. On this occasion, no one is explicitly asking the question so I can take the chance to define it and its importance on my own terms, as I understand it.

Almost all data can include an element of location -- address, postal code, geographic coordinates. A geographic information system (GIS) allows us to integrate, manage, analyze and display this geographically referenced information. Depending on the knowledge level and objectives of the user, a GIS can take on many definitions:

• a container of digital maps
• a computerized tool for solving spatial problems
• a digital inventory of geographically distributed facilities and objects, in the case of utilities management, transportation, or resource management
• a tool for visualizing geographic information to reveal patterns or relationships that are otherwise invisible
• a means of performing operations on spatial data that would be too complicated or tedious if performed by hand

What Can It Do?

Geography plays a role in nearly every decision we make: choosing sites for facilities or services, targeting market segments, planning distribution networks, evaluating emergency response routes and providing monitoring during and after an emergency, redrawing political boundaries. All of these problems involve questions of geography, as do countless others. So, as it has been said: "The application of GIS technology is limited only by the imagination of those who use it."

Some concrete examples pulled from this site:

• showing distribution of food banks and shelters in relation to low-income populations to determine whether more services are needed and where
• identifying where recommendations for environmental improvements have been made within a watershed to determine gaps
• development of efficient delivery routes for transportation firms
• plotting climate and land characteristics in order to identify possible locations for lost settlements of the norsemen in North America
• plotting contaminated underwater streams to see if they affect water wells for residents
  
• evaluating emergency response routes and providing ongoing monitoring during and after an emergency (used extensively for recovery effort in Florida during and after Hurricane Andrew in August 1992)

In general, as I see it the importance of GIS is its power to inform better decisions. The ability to integrate vast amounts of different types of data (with location as the unifying element), then visualize, query, and perform analyses on the data, allows the user to see patterns that might otherwise be invisible and predict the outcome of a given decision. This capability -- simulation of a particular decision to assess its effects before actually implementing it -- is and will become more important as we address environmental problems and increasing resource scarcity. Things must be done right the first time around, in the most efficient and least wasteful/harmful manner possible -- be it urban planning, construction, manufacturing, etc. Although counterproductive in a monetary based economy, where it's in the firm's best interest to design a product or service that will soon become obsolete to ensure continued business, we must soon get in the habit of using resources responsibly, doing things perfectly the first time around so they don't need to be redone a few months or years in the future.

Walkability Map of Listowel, Ontario: Cartastrophe or a Good Start?

A walkable community is one where all services and amenities are close at hand to residential areas (or integrated into residential areas in mixed use development), eliminating the need to use or ideally to even own a vehicle. The benefits of such walkable neighbourhood arrangements to our health, the environment and our communities are obvious:

• It's been shown that residents of pedestrian-friendly neighbourhoods are healthier and weigh less than their sprawling neighbourhood counterparts, and because of driving less suffer few car accidents.
• The environmental problems associated with vehicle emissions are no secret nowadays: poor air quality, greenhouse gases and global warming. Designing lower emission vehicles, despite all the hype and marketing from car companies, is not the solution. (Is smoking light cigarettes a good idea? No, kick the habit!) Well designed towns and cities that eliminate our reliance on vehicles and fossil fuels are what's desperately needed. Walking and cycling are zero-pollution means of transportation.
• Compactness and density are essential conditions for a walkable neighbourhood. A higher population density makes public transportation and bicycle infrastructure feasible. Bus and rail routes and bike paths/lanes can serve a greater number of people. Dense, walkable neighborhoods also provide local businesses with increased foot traffic, allowing them to thrive. Not having to drive between destinations allows pedestrians to stop at more stores/restaurants/theaters/etc.
• A walkable neighbourhood promotes face-to-face interaction and community involvement. Instead of being couped up in a vehicle en route, isolated from the world, the morning commute could be a bike ride alongside a neighbour or a trip to the grocery store a short walk in the fresh air, encountering friends along the way.

Now, on to the map. It's quite simplistic and possibly full of cartographic faux pas', being a first attempt, but it hopefully conveys the message with as little confusion as possible. I used Quantum GIS to put together the map, a free to download desktop GIS application. The whole process was quite instructive, having never done it before. I searched for and downloaded the datasets, chose an appropriate (hopefully) projection for my area of interest (UTM, Zone 17N), imported the layers into QGIS and decided on color schemes, transparency, and other design concerns. I also made use of the "buffer" function to create an area around the town's bike paths to be displayed -- a linear park essentially -- and to create 500m radius "walkability" circles around the supermarkets and schools, two of the most frequented locations in a daily routine. Rather than using buffer circles which don't account for the actual layout of roads, a walking time cost analysis showing along-street displacement times from the location in question would have been more appropriate. Unfortunately that's still over my head at this point, and I'm not certain that QGIS has that capability. Well, here it is...

Click here for a larger image.
Comments and criticisms welcome.