Information Systems and GIS Chapter 2 Slides from James Pick, Geo-Business: GIS in the Digital Organization, John Wiley and Sons, Copyright © 2008 John Wiley and Sons. DO NOT CIRCULATE WITHOUT PERMISSION OF JAMES PICK Copyright (c) 2008 by John Wiley and Sons

Elements of a GIS A GIS –Accesses spatial boundaries and attribute (i.e. non-spatial) data –Analyzes the spatial and attribute data A GIS includes: –A data-base –Tools, algorithms, and models for manipulate spatial data and attributes Copyright (c) 2008 by John Wiley and Sons

Map and Attribute Information Spatial boundary data, attributes, and data-bases form a basis for spatial data. Central idea in GIS is location and the data associated with it. Also a key aspect is that the location and the data can be linked together. Copyright (c) 2008 by John Wiley and Sons

Design Elements of a GIS (Source: Pick, 2007) Copyright (c) 2008 by John Wiley and Sons

Example of Processing with Simple GIS (Source: Pick, 2007) Copyright (c) 2008 by John Wiley and Sons

Points, Lines, and Polygons (Source: Pick, 2007) Copyright (c) 2008 by John Wiley and Sons

Relationship of Spatial and Attribute Data in Multiple GIS Layers Adapted from West, Copyright (c) 2008 by John Wiley and Sons

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) Copyright (c) 2008 by John Wiley and Sons

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. Copyright (c) 2008 by John Wiley and Sons

Coordinate System – Lat, Long Locations are represented in a GIS with the use of X and Y coordinates, which represent real-world coordinates (in 3 dimensions) that have been projected onto a two dimensional surface. The geographic grid of latitude and longitude is a commonly used geographic reference system. It is not a true coordinate system, however because it measures angles from the center of the earth in degrees, minutes, and seconds rather than distances on the earth's surface. Copyright (c) 2008 by John Wiley and Sons

Diagram of Lat-Long Coordinate System for the Earth (Source: Bolstad, 2005) Copyright (c) 2008 by John Wiley and Sons

GIS in 3 Dimensions – Example of a 3-D Image of the Built Environment in London Copyright (c) 2008 by John Wiley and Sons

Map Scale Maps reduce the size of the earth. Map at 1:1 scale means 1 foot on the map is the same as 1 foot on the earth. It would be a life- sized drawing. 1:500 scale means that 1 foot on the map is the same as 500 feet on the earth. An idea of scale is that 1:40,000,000 implies that the circumference of the earth at the equator would map to the size of a postage stamp. U.S. – most important scales at 1:100,000 and 1:24,000 (USGS maps). Also 1:50,000 is important. Copyright (c) 2008 by John Wiley and Sons

Geographic Information A map stored inside a GIS is described by coordinates. A sophisticated map contains a huge number of coordinates. This is possible because of the huge gains in storage described in the introductory lecture. Copyright (c) 2008 by John Wiley and Sons

GIS Structures – Features and Feature Properties GIS structures are put together from points, lines, and areas (polygons). Points – the basic coordinate location – zero dimensional Lines – connected together by two points – one dimensional. Areas (also called polygons) bounded by three or more points connected by lines – two dimensional. Points, lines, and areas are features. They are further defined by feature properties of size, distribution, neighborhood, shape, pattern, contiguity, shape, and orientation. Copyright (c) 2008 by John Wiley and Sons

Referent Disciplines for GIS Concepts and Theories Copyright (c) 2008 by John Wiley and Sons

GPS Devices for Field Hardened Trimble GPS with ArcPadAsus R2HV A1 UMPC Has Bluetooth, Wireless Windows Vista. Can have GPS Add-on and connect by Blue Tooth to Digital Camera Copyright (c) 2008 by John Wiley and Sons

Satellite and Aerial Imagery Which can be Input into a GIS Copyright (c) 2008 by John Wiley and Sons

Combining Satellite Imagery and Digital Photo in a GIS Copyright (c) 2008 by John Wiley and Sons

Spatial Analysis GIS analysis techniques consist of methods that are used in the spatial analysis, modeling, and statistical analysis of a GIS. This section describes a few of the most common spatial analysis techniques. Spatial analysis consists of analytical techniques that emphasize the map layers. It relates and compares the features of the physical locations of objects in space (Getis, 1999; Longley and Batty, 2003). Since it draws from geography, –it is not familiar to most IS researchers. Modeling and statistical analysis methods include many methods and techniques well known in business disciplines, but often modified to take into account spatial relationships. These methods are based both on attribute and spatial data, Specialized statistical methods that include space are referred to as geostatistics (Getis, 1999). Copyright (c) 2008 by John Wiley and Sons

Map Overlay Since spatial analysis techniques compare spatial features, they can, for example, determine how many points are inside a polygon, how many line segments cross a polygon boundary, or how much polygons overlap each other. This is done by a technique known as map overlay A practical example would be to ask how many highways and streets (lines) cross a zone of retail businesses. Copyright (c) 2008 by John Wiley and Sons

Spatial Analysis – Map Overlay Copyright (c) 2008 by John Wiley and Sons

Buffer Analysis In buffer analysis, GIS software forms bands on all sides of a point, line, or polygon, in order to perform analysis within the bands. A simple example would be to assign half- mile buffers on both sides of a highway, in order to query how many service stations are within the buffer. Copyright (c) 2008 by John Wiley and Sons

Proximity Analysis Proximity analysis assesses how close certain map features are to other map features. For instance, it can determine how many customers are in a grocery store’s trade area. Class Question. Discuss with your neighbor another use for Proximity Analysis. Copyright (c) 2008 by John Wiley and Sons

Modeling and Forecasting Forecasting and simulation models can be built with spatial data, and the results displayed in map form. An example is a model that projects the population distribution of retail consumers within a county, based on starting year data. The future population distributions of retail consumers can be mapped, to inform businesses and the public. Copyright (c) 2008 by John Wiley and Sons

Spatial Modeling of Industrial Locations for LA Using Location Quotient Source: Greene and Pick, 2006 Copyright (c) 2008 by John Wiley and Sons

Statistical Analysis Statistical models are often applied to study the relationships of certain spatially referenced attributes to other attributes (Getis, 1999). They include correlation, regression, analysis of variance (ANOVA), cluster analysis, principles components, and t tests. The input data, as well as the results, of many of these models can be represented as spatial displays. This enhances understanding of the geographical effects and influences. Although beyond the scope of this chapter, a specialized part of statistics, called geostatistics, takes especially into account spatial effects and interactions, such as spatial autocorrelation (Getis, 2000). An example is predicting the future spatial patterns of demand for advertising services in an urbanized area. Copyright (c) 2008 by John Wiley and Sons

Summary Information Systems and GIS are closely related to each other GIS uses spatial boundaries and attributes to perform spatial analysis GIS requires an underlying knowledge of geographical principles such as coordinate systems. Specialized equipment is used for input of information into a GIS GIS analysis techniques are utilized to map comparisions, forecasts, spatial models, and geo-statistical analysis. Copyright (c) 2008 by John Wiley and Sons