GIS

GEOGRAPHIC GEOGRAPHIC INFORMATION SYSTEMINFORMATION SYSTEM

DEVELOPED BY :POONAM SHARMA

INTRODUCTION

Geographic Information System

GIS is a set of computerized tools for collecting, GIS is a set of computerized tools for collecting, storing, retrieving, transforming and displaying storing, retrieving, transforming and displaying spatial data.spatial data.

WHAT IS GIS ?

A particular form of Information system applied A particular form of Information system applied to geographical data.to geographical data.

A system is a group of connected entities and A system is a group of connected entities and activities which interact for a common purpose.activities which interact for a common purpose.

What is Not GIS ?

GPS : Global Positioning System Global Positioning System

A static map : paper or digital paper or digital Maps are often a Maps are often a “product” of GIS of GIS

A way to visualize the analysisA way to visualize the analysis

A A software package package

How do we create Geographic Information ?

Aerial Aerial PhotographyPhotography

Land Land SurveyingSurveying

GPSGPSWhatWhat WhereWhere

Geographic Geographic InformationInformation

Fields Fields SamplesSamples

Population Population CensusCensus

Administrative Administrative RecordsRecords

Why is GIS Important ?

GIS technology is to geographical analysis what GIS technology is to geographical analysis what the microscope, the telescope,and computers have the microscope, the telescope,and computers have been to other sciences.been to other sciences.

It integrates spatial information within a It integrates spatial information within a single system.single system.

It allows us to manipulate and display It allows us to manipulate and display geographical knowledge in new and exciting geographical knowledge in new and exciting ways.ways.

Why is GIS so HOT ?

GIS gives a GIS gives a “high tech” feel to geographic feel to geographic information.information.

Maps are fascinating and so are maps in Maps are fascinating and so are maps in computers.computers.

Cont…

There is increasing interest in geography and There is increasing interest in geography and geographic education.geographic education.

GIS is an important tool in understanding GIS is an important tool in understanding and managing the environment .and managing the environment .

Disciplines & Technologies

GIS is a convergence of technological fields and GIS is a convergence of technological fields and traditional disciplines.traditional disciplines.

GIS has been called an GIS has been called an “Enabling Technology”.

Geography

Broadly concerned with understanding the world Broadly concerned with understanding the world and man’s place in it.and man’s place in it.

Long tradition in spatial analysis.Long tradition in spatial analysis.

Provides techniques for conducting spatial analysis.Provides techniques for conducting spatial analysis.

Cartography

Computer cartography provides methods for digitalComputer cartography provides methods for digital representation.representation.

It is concerned with the display of Spatial It is concerned with the display of Spatial Information.Information.

It provides long tradition in the design of maps It provides long tradition in the design of maps which is an important form of output from GIS.which is an important form of output from GIS.

Remote Sensing

Remote Sensing includes techniques for data Remote Sensing includes techniques for data acquisition and processing anywhere on the globe acquisition and processing anywhere on the globe at low cost.at low cost.

Images from space and the air are major source of Images from space and the air are major source of geographical data.geographical data.

Interpreted data from a remote sensing system can Interpreted data from a remote sensing system can be merged with other data layers in a GISbe merged with other data layers in a GIS

Photogrammetry

Photogrammetry is the source of most data used for Photogrammetry is the source of most data used for input to GIS.input to GIS.

In Photogrammetry we use aerial photography In Photogrammetry we use aerial photography for making measurements.for making measurements.

Statistics

Statistics is important in understanding issues Statistics is important in understanding issues of error and uncertainty in GIS data.of error and uncertainty in GIS data.

Many models are built using GIS are Many models are built using GIS are statistical in nature.statistical in nature.

Many statistical techniques are used for Many statistical techniques are used for analysis.analysis.

Computer Science

CAD provides software, techniques for provides software, techniques for data input, display and visualization.data input, display and visualization.

Advances in Advances in computer graphics provide provide hardware, software for handling and displaying hardware, software for handling and displaying graphic objects.graphic objects.

DBMS contribute procedures for system contribute procedures for system design and handling large volume of data.design and handling large volume of data.

GIS as a set of InterrelatedSubsystem

Data Processing SystemData Processing System

Information User SubsystemInformation User Subsystem

Data Analysis SubsystemData Analysis Subsystem

Data Acquisition : from maps, images or from maps, images or field surveys.field surveys.

Data Input : data must be input from source data must be input from source material to the digital database.material to the digital database.

Data Storage : how often is it used, how how often is it used, how should it be updated, is it confidential?should it be updated, is it confidential?

Data Processing Subsystem

Data Analysis Subsystem

Retrieval and Analysis : may be simple may be simple responses to queries, or complex statistical responses to queries, or complex statistical analysis of large sets of data.analysis of large sets of data.

Information Output : how to display the how to display the results? As maps or tables? Or will the results? As maps or tables? Or will the information be fed into some other digital information be fed into some other digital system ?system ?

Information User Subsystem

Users may be researchers, planners, Users may be researchers, planners, managers.managers.

It provides interaction between GIS group It provides interaction between GIS group and users to plan analytical procedures and and users to plan analytical procedures and data structures.data structures.

Data from MapsData from Maps

Tabular dataTabular data

Field dataField data

Data from other Data from other digital databasedigital database

Remote sensingRemote sensing

Global positioning Global positioning systemsystem

Reports Reports

Maps Maps

Photographic Photographic products products

Statistics Statistics

To other digital To other digital databasedatabase

Input to ModelsInput to Models

Geographic Information SystemGeographic Information System

Database ManagementDatabase Management

Ideal GIS