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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 two. Source: Clarke, 2003.
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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 two Source: 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 (Source: Greene and Pick, 2005)
Map Layer A GIS might have a single map layer, but more commonly include two or more layers
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
Sometimes the greatest value comes from simply looking at your data from a different perspective! • Over 50% of customers live within 2 miles • Over 80% of customers live within 4 miles
Retail/Site Selection/Marketing • Site Selection • Find best locations for new stores • Identify inefficient stores • Trade Areas • Market Penetration • Market Share • Target Marketing • Understand customer demographics • Identify untapped enclaves of future customers • Direct 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 (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 Spatial 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.
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.