04-04-2011, 04:05 PM
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1.1 Overview
Geographic Information System (GIS) is a computer based information system used to digitally represent and analyse the geographic features present on the Earth' surface and the events (non-spatial attributes linked to the geography under study) that taking place on it. The meaning to represent digitally is to convert analog (smooth line) into a digital form."Every object present on the Earth can be geo-referenced", is the fundamental key of associating any database to GIS. Here, term 'database' is a collection of information about things and their relationship to each other, and 'geo-referencing' refers to the location of a layer or coverage in space defined by the co-ordinate referencing system. Work on GIS began in late 1950s, but first GIS software came only in late 1970s from the lab of the ESRI. Canada was the pioneer in the development of GIS as a result of innovations dating back to early 1960s. Much of the credit for the early development of GIS goes to Roger Tomilson. Evolution of GIS has transformed and revolutionized the ways in which planners, engineers, managers etc. conduct the database management and analysis.
1.2 Definition of GIS
A GIS is an information system designed to work with data referenced by spatial / geographical coordinates. In other words, GIS is both a database system with specific capabilities for spatially referenced data as well as a set of operations for working with the data. It may also be considered as a higher order map. GIS technology integrates common database operations such as query and statistical analysis with the unique visualization and geographic analysis benefits offered by maps. These abilities distinguish GIS from other information systems and make it valuable to a wide range of public and private enterprises for explaining events, predicting outcomes, and planning strategies. (ESRI). A Geographic Information System is a computer based system which is used to digitally reproduce and analyse the feature present on earth surface and the events that take place on it. In the light of the fact that almost 70% of the data has geographical reference as it's denominator, it becomes imperative to underline the importance of a system which can represent geographically.
A typical GIS can be understood by the help of various definitions given below:-
A geographic information system (GIS) is a computer-based tool for mapping and analyzing things that exist and events that happen on Earth
Burrough in 1986 defined GIS as, "Set of tools for collecting, storing, retrieving at will, transforming and displaying spatial data from the real world for a particular set of purposes"
Arnoff in 1989 defines GIS as, "a computer based system that provides four sets of capabilities to handle geo-referenced data :
• data input
• data management (data storage and retrieval)
• manipulation and analysis
• data output. "
Hence GIS is looked upon as a tool to assist in decision-making and management of attributes that needs to be analysed spatially.
1.3 History
Work on GIS began in late 1950s, but first GIS software came only in late 1970s from the lab of the ESRI. Canada was the pioneer in the development of GIS as a result of innovations dating back to early 1960s. Much of the credit for the early development of GIS goes to Roger Tomilson. Evolution of GIS has transformed and revolutionized the the ways in which planners, engineers, managers etc. conduct the database management and analysis.
1.4 Need of GIS
Many professionals, such as foresters, urban planners, and geologists, have recognized the importance of spatial dimensions in organising & analysing information. Whether a discipline is concerned with the very practical aspects of business, or is concerned with purely academic research, geographic information system can introduce a perspective, which can provide valuable insights as
1. 70% of the information has geographic location as it's denominator making spatial analysis an essential tool.
2. Ability to assimilate divergent sources of data both spatial and non-spatial (attribute data).
3. Visualization Impact
4. Analytical Capability
5. Sharing of Information
Factors aiding the rise of GIS.
Revolution in Information Technology.
• Computer Technology.
• Remote Sensing.
• Global Positioning System.
Communication Technology.
Rapidly declining cost of Computer Hardware, and at the same time, exponential growth of operational speed of computers.
Enhanced functionality of software and their user-friendliness.
Visualizing impact of GIS corroborating the Chinese proverb "a picture is worth a thousand words."
Geographical feature and data describing it are part of our everyday lives & most of our everyday decisions are influenced by some facet of Geography.
1.4.1 Involvement in Various Sectors
80% of local government activities estimated to be geographically based
– plats, zoning, public works (streets, water supply, sewers), garbage collection, land ownership and valuation, public safety (fire and police)
• a significant portion of state government has a geographical component
– natural resource management
– highways and transportation
• businesses use GIS for a very wide array of applications
– retail site selection & customer analysis
– logistics: vehicle tracking & routing
– natural resource exploration (petroleum, etc.)
– precision agriculture
– civil engineering and construction
• Military and defense
– Battlefield management
– Satellite imagery interpretation
• scientific research employs GIS
– geography, geology, botany
– anthropology, sociology, economics, political science
1.5 Related Technologies
GISs are closely related to several other types of information systems, but it is the ability to manipulate and analyze geographic data that sets GIS technology apart. Although there are no hard and fast rules about how to classify information systems, the following discussion should help differentiate GIS from desktop mapping, computer-aided design (CAD), remote sensing, DBMS, and global positioning systems (GPS) technologies.
Desktop-Mapping
A desktop mapping system uses the map metaphor to organize data and user interaction. The focus of such systems is the creation of maps: the map is the database. Most desktop mapping systems have more limited data management, spatial analysis, and customization capabilities. Desktop mapping systems operate on desktop computers such as PCs, Macintoshes, and smaller UNIX workstations.
CAD
CAD systems evolved to create designs and plans of buildings and infrastructure. This activity required that components of fixed characteristics be assembled to create the whole structure. These systems require few rules to specify how components can be assembled and very limited analytical capabilities. CAD systems have been extended to support maps but typically have limited utility for managing and analyzing large geographic databases.
RemoteSensingandGPS
Remote sensing is the art and science of making measurements of the earth using sensors such as cameras carried on airplanes, GPS receivers, or other devices. These sensors collect data in the form of images and provide specialized capabilities for manipulating, analyzing, and visualizing those images. Lacking strong geographic data management and analytical operations, they cannot be called true GISs.
DBMS
Database management systems specialize in the storage and management of all types of data including geographic data. DBMSs are optimized to store and retrieve data and many GISs rely on them for this purpose. They do not have the analytic and visualization tools common to GIS.
1.6 Role of GIS
GIS make possible the automation of activities involving geographic data
– map production
– calculation of areas, distances, route lengths
– measurement of slope, aspect, viewshed
– logistics: route planning, vehicle tracking, traffic management
• allow for the integration of data hitherto confined to independent domains (e.g property maps and air photos).
• by tieing data to maps, permits the succinct communication of complex spatial patterns (e.g environmental sensitivity).
• provides answers to spatial queries (how many elderly in Richardson live further than 10 minutes at rush hour from ambulance service?)
• perform complex spatial modelling (what if scenarios for transportation planning, disaster planning, resource management, utility design)
It has find its use in every spheres of day to day life. It comprises of following:
• Urban Planning, Management & Policy
– Zoning, subdivision planning
– Land acquisition
– Economic development
– Code enforcement
– Housing renovation programs
– Emergency response
– Crime analysis
– Tax assessment
• Environmental Sciences
– Monitoring environmental risk
– Modeling stormwater runoff
– Management of watersheds, floodplains, wetlands, forests, aquifers
– Environmental Impact Analysis
– Hazardous or toxic facility siting
– Groundwater modeling and contamination tracking
• Political Science
– Redistricting
– Analysis of election results
– Predictive modeling
• Civil Engineering/Utility
– Locating underground facilities
– Designing alignment for freeways, transit
– Coordination of infrastructure maintenance
• Business
– Demographic Analysis
– Market Penetration/ Share Analysis
– Site Selection
• Education Administration
– Attendance Area Maintenance
– Enrollment Projections
– School Bus Routing
• Real Estate
– Neighborhood land prices
– Traffic Impact Analysis
– Determination of Highest and Best Use
• Health Care
– Epidemiology
– Needs Analysis
– Service Inventory
1.1 Overview
Geographic Information System (GIS) is a computer based information system used to digitally represent and analyse the geographic features present on the Earth' surface and the events (non-spatial attributes linked to the geography under study) that taking place on it. The meaning to represent digitally is to convert analog (smooth line) into a digital form."Every object present on the Earth can be geo-referenced", is the fundamental key of associating any database to GIS. Here, term 'database' is a collection of information about things and their relationship to each other, and 'geo-referencing' refers to the location of a layer or coverage in space defined by the co-ordinate referencing system. Work on GIS began in late 1950s, but first GIS software came only in late 1970s from the lab of the ESRI. Canada was the pioneer in the development of GIS as a result of innovations dating back to early 1960s. Much of the credit for the early development of GIS goes to Roger Tomilson. Evolution of GIS has transformed and revolutionized the ways in which planners, engineers, managers etc. conduct the database management and analysis.
1.2 Definition of GIS
A GIS is an information system designed to work with data referenced by spatial / geographical coordinates. In other words, GIS is both a database system with specific capabilities for spatially referenced data as well as a set of operations for working with the data. It may also be considered as a higher order map. GIS technology integrates common database operations such as query and statistical analysis with the unique visualization and geographic analysis benefits offered by maps. These abilities distinguish GIS from other information systems and make it valuable to a wide range of public and private enterprises for explaining events, predicting outcomes, and planning strategies. (ESRI). A Geographic Information System is a computer based system which is used to digitally reproduce and analyse the feature present on earth surface and the events that take place on it. In the light of the fact that almost 70% of the data has geographical reference as it's denominator, it becomes imperative to underline the importance of a system which can represent geographically.
A typical GIS can be understood by the help of various definitions given below:-
A geographic information system (GIS) is a computer-based tool for mapping and analyzing things that exist and events that happen on Earth
Burrough in 1986 defined GIS as, "Set of tools for collecting, storing, retrieving at will, transforming and displaying spatial data from the real world for a particular set of purposes"
Arnoff in 1989 defines GIS as, "a computer based system that provides four sets of capabilities to handle geo-referenced data :
• data input
• data management (data storage and retrieval)
• manipulation and analysis
• data output. "
Hence GIS is looked upon as a tool to assist in decision-making and management of attributes that needs to be analysed spatially.
1.3 History
Work on GIS began in late 1950s, but first GIS software came only in late 1970s from the lab of the ESRI. Canada was the pioneer in the development of GIS as a result of innovations dating back to early 1960s. Much of the credit for the early development of GIS goes to Roger Tomilson. Evolution of GIS has transformed and revolutionized the the ways in which planners, engineers, managers etc. conduct the database management and analysis.
1.4 Need of GIS
Many professionals, such as foresters, urban planners, and geologists, have recognized the importance of spatial dimensions in organising & analysing information. Whether a discipline is concerned with the very practical aspects of business, or is concerned with purely academic research, geographic information system can introduce a perspective, which can provide valuable insights as
1. 70% of the information has geographic location as it's denominator making spatial analysis an essential tool.
2. Ability to assimilate divergent sources of data both spatial and non-spatial (attribute data).
3. Visualization Impact
4. Analytical Capability
5. Sharing of Information
Factors aiding the rise of GIS.
Revolution in Information Technology.
• Computer Technology.
• Remote Sensing.
• Global Positioning System.
Communication Technology.
Rapidly declining cost of Computer Hardware, and at the same time, exponential growth of operational speed of computers.
Enhanced functionality of software and their user-friendliness.
Visualizing impact of GIS corroborating the Chinese proverb "a picture is worth a thousand words."
Geographical feature and data describing it are part of our everyday lives & most of our everyday decisions are influenced by some facet of Geography.
1.4.1 Involvement in Various Sectors
80% of local government activities estimated to be geographically based
– plats, zoning, public works (streets, water supply, sewers), garbage collection, land ownership and valuation, public safety (fire and police)
• a significant portion of state government has a geographical component
– natural resource management
– highways and transportation
• businesses use GIS for a very wide array of applications
– retail site selection & customer analysis
– logistics: vehicle tracking & routing
– natural resource exploration (petroleum, etc.)
– precision agriculture
– civil engineering and construction
• Military and defense
– Battlefield management
– Satellite imagery interpretation
• scientific research employs GIS
– geography, geology, botany
– anthropology, sociology, economics, political science
1.5 Related Technologies
GISs are closely related to several other types of information systems, but it is the ability to manipulate and analyze geographic data that sets GIS technology apart. Although there are no hard and fast rules about how to classify information systems, the following discussion should help differentiate GIS from desktop mapping, computer-aided design (CAD), remote sensing, DBMS, and global positioning systems (GPS) technologies.
Desktop-Mapping
A desktop mapping system uses the map metaphor to organize data and user interaction. The focus of such systems is the creation of maps: the map is the database. Most desktop mapping systems have more limited data management, spatial analysis, and customization capabilities. Desktop mapping systems operate on desktop computers such as PCs, Macintoshes, and smaller UNIX workstations.
CAD
CAD systems evolved to create designs and plans of buildings and infrastructure. This activity required that components of fixed characteristics be assembled to create the whole structure. These systems require few rules to specify how components can be assembled and very limited analytical capabilities. CAD systems have been extended to support maps but typically have limited utility for managing and analyzing large geographic databases.
RemoteSensingandGPS
Remote sensing is the art and science of making measurements of the earth using sensors such as cameras carried on airplanes, GPS receivers, or other devices. These sensors collect data in the form of images and provide specialized capabilities for manipulating, analyzing, and visualizing those images. Lacking strong geographic data management and analytical operations, they cannot be called true GISs.
DBMS
Database management systems specialize in the storage and management of all types of data including geographic data. DBMSs are optimized to store and retrieve data and many GISs rely on them for this purpose. They do not have the analytic and visualization tools common to GIS.
1.6 Role of GIS
GIS make possible the automation of activities involving geographic data
– map production
– calculation of areas, distances, route lengths
– measurement of slope, aspect, viewshed
– logistics: route planning, vehicle tracking, traffic management
• allow for the integration of data hitherto confined to independent domains (e.g property maps and air photos).
• by tieing data to maps, permits the succinct communication of complex spatial patterns (e.g environmental sensitivity).
• provides answers to spatial queries (how many elderly in Richardson live further than 10 minutes at rush hour from ambulance service?)
• perform complex spatial modelling (what if scenarios for transportation planning, disaster planning, resource management, utility design)
It has find its use in every spheres of day to day life. It comprises of following:
• Urban Planning, Management & Policy
– Zoning, subdivision planning
– Land acquisition
– Economic development
– Code enforcement
– Housing renovation programs
– Emergency response
– Crime analysis
– Tax assessment
• Environmental Sciences
– Monitoring environmental risk
– Modeling stormwater runoff
– Management of watersheds, floodplains, wetlands, forests, aquifers
– Environmental Impact Analysis
– Hazardous or toxic facility siting
– Groundwater modeling and contamination tracking
• Political Science
– Redistricting
– Analysis of election results
– Predictive modeling
• Civil Engineering/Utility
– Locating underground facilities
– Designing alignment for freeways, transit
– Coordination of infrastructure maintenance
• Business
– Demographic Analysis
– Market Penetration/ Share Analysis
– Site Selection
• Education Administration
– Attendance Area Maintenance
– Enrollment Projections
– School Bus Routing
• Real Estate
– Neighborhood land prices
– Traffic Impact Analysis
– Determination of Highest and Best Use
• Health Care
– Epidemiology
– Needs Analysis
– Service Inventory