Introduction to GIS. Geographical basis, data, boundary files, map basics, GIS design elements============================Fundamental Definition of GIS

A GIS consists of the following elements:

• Data-base of attributes

• Spatial information

• Some way to link the twoSource: Clarke, 2003.

GIS as a Toolbox

• GIS can be viewed as a set of tools.• Sometimes this is called a process

definition because the subtasks are sequentially arranged.

• An example of using a set of tools as procedures is – Get addresses from a marketing list– Geocode them (to get X—Y points)– Map them

Design Elements of a GIS

Attribute TablesMap Layers

Figure 1.19. Design Elements of a GIS

Attribute Input Data

Boundary File Input Data

Analysis and Modeling

Output

(Source: Greene and Pick, 2005)

Map Layer• A GIS might have a

single map layer, but more commonly include two or more layers

Example of Processing with Simple GIS

Baseball example of non-spatial versus spatial query.

Keith Clarke gives the example of baseball cards. If we associate the X-Y coordinate location of the stadium that the player is associated with, we are adding a spatial attribute.

•Example of query without the spatial attribute. “Find all players with a batting average over .300. •Example of query with the spatial attribute. “Find all players with a batting average over .250 and whose location is within 300 miles of Yankee Stadium.”

Source: Clarke, 2003)

Geographic Location• How is geographic location determined. Often

by latitude and longitude.

• It can be by more advanced coordinate systems, such as 3-D, but lat-long will do for now.

• The geographic grid of latitude and longitude is a commonly used geographic reference system.

Points, Lines, and Polygons

Source: Clarke, 2003.

Map Layer• A GIS might have a

single map layer, but more commonly include two or more layers

Addresses of business clients, converted to points.

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Distance (Miles)

% of Customers By Distance

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Distance (Miles)

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Sometimes the greatest Sometimes the greatest value comes from simply value comes from simply looking at your data from looking at your data from a different perspective!a different perspective!

•Over 50% of customers live within 2 miles

•Over 80% of customers live within 4 miles

Retail/Site Selection/MarketingSite SelectionSite Selection•Find best locations for new storesFind best locations for new stores•Identify inefficient storesIdentify inefficient stores•Trade AreasTrade Areas•Market PenetrationMarket Penetration•Market ShareMarket Share

Target MarketingTarget Marketing•Understand customer demographicsUnderstand customer demographics•Identify untapped enclaves of future Identify untapped enclaves of future customers customers•Direct MailingsDirect Mailings

LQs for Nine Employment Sectors, LA

(Source:Greene and Stager, 2005)

Worksheet and Discussion

• Take five minutes and think through what you consider the two locational (geographic) aspects of your business that are the most important influences on productivity or profit.

• Write down these two locational aspects on a piece of paper.

Map Overlay Example

Input - census blocks Overlay - store trade areas Result of union

(Source: Greene and Stager, 2005)

Overlaying map layers:This example has layers for city boundaries, transportation, land use, and business locations.

Buffer Analysis

• In buffering, GIS software forms bands on either side of a points, line, or polygon to perform analysis within the bands.

• Simple example: to assign half-mile buffers on both sides of highway, and ask how many service stations are within the buffer

Example of Buffering

Example of Example of Spatial Spatial

Change.Change.

Change in population densities in

Chicago, 1940-2000

Source: Greene and Pick, 2006

Proximity Analysis

• It assesses how close certain map objects are to other map objects.

• For example, it can determine how close the population residing in a census tract is to a competing set of grocery stores.

Understanding the demographics of your market area.

Conclusion• GIS can be used to analyze small business problems• Customer mapping can reveal trends important to

business planning and profits.• Overlays can increase the information available.• Time sequences can show changes in business activities

and markets over time.• Spatial analysis can lead to better targeting of

customers, facilities, workers, and other business entities.

• GIS is a technology to make more data more usable and put it to greater use for efficiencies, better performance, and profits.

• Geography can be important to the success of your business or enterprise.