Babu Ram Dawadi, IOE Pulchowk Campus

DefinitionA Geographic Information System (GIS) is a

computer based system that facilitates the phases of data entry, data analysis and data presentation especially in cases when we are dealing with georeferenced data.

A Geographic Information System (GIS) is a computer-based mapping tool that enables geographic or spatial data capture, storage, retrieval, manipulation, analysis, modeling and presentation of the real world scenario. Basically, GIS is working on the principle of geography. Geography or GIS is now proving its potential and widely accepted by inter-disciplinary experts at various levels to better manage the earth’s resources.

Def…GIS is a System of computer software,

hardware and data, and personnel to help manipulate, analyze and present information that is tied to a spatial location –spatial location– usually a geographic locationinformation– visualization of analysis of datasystem– linking software, hardware, datapersonnel– a thinking explorer who is key to

the power of GIS

History of GISDecade Milestones for computer-based GIS

1960’s - Canada Geographic Information System (CGIS) developed: national land inventory pioneered many aspects of GIS

- Harvard Lab for Computer Graphics and Spatial Analysis: pioneered software for spatial data handling

- US Bureau of Census developed DIME data format

- ESRI founded

1970’s - CGIS fully operational (and still operational today)

- First Landsat satellite launched (USA)

- CARIS (Computer Aided Resource Information System) founded

- USGS (United States Geological Survey) begins Geographical Information Retrieval and Analysis System (GIRAS) to manage and analyze large land resources databases and Digital Line Graph (DLG) data format

- ERDAS (Earth Resources Data Analysis System) founded

- ODYSSEY GIS launched (first vector GIS)

History of GISDecade Milestones for computer-based GIS

1980’s - ESRI launches ARC/INFO (vector GIS)

- GPS became operational

- US Army Corp of Engineers develop GRASS (raster GIS)

- MapInfo founded

- First SPOT satellite launched (Europe)

- IDRISI Project started (GIS program)

- SPANS GIS produced

- National Center for Geographic Information and Analysis (NCGIA) established in USA

- TIGER digital data

History of GISDecade Milestones for computer-based GIS

1990’s - MapInfo for Windows, Intergraph, Autodesk, others

- ESRI produces ArcView and ARCGIS

- $7+ billion industry

GIS SoftwareThe geoprocessing engines of GISMajor functions

Collect, store, mange, query, analyze and present

Key termsProgram – collections of instructions to

manipulate dataPackage – integrated collection of programsComponent – self-contained, reusable software

building blocks

User Interface Applications

Geographic Tools

Data AccessSpatial

ReferenceVector

DataManager

Raster

Output

Editing

Analysis

CustomizationDisplay

Translation

  Autodesk ESRI Intergraph MapInfo Smallworld

Viewer AutoCAD LT

ArcReader GeoMedia Viewer ProViewer Custom

Desktop World ArcView GeoMedia MapInfo Professional

Spatial Intelligence

Profess-ional

AutoCAD / Map

ArcEditorArcInfo

GeoMedia Pro MapInfo Professional

Smallworld GIS

Hand-held OnSite ArcPad IntelliWhere MapXtend Scout

Database Server

GIS Server

ArcSDE Uses Oracle Spatial

SpatialWare Part of Smallworld GIS

Component In several products

MapObjects

Part of GeoMedia MapX, MapJ Part of Smallworld GIS

Internet MapGuide ArcIMS GeoMedia Web Map, GeoMedia Web Enterprise

MapXtreme, MapXSite

Smallworld Internet Applic- ation Server

CAD AutoCAD Map

In several products

In several products

In several products

Part of Smallworld GIS

Number ofUsers

CostInternetViewer

ComponentHand-heldDesktop

Professional

Functionality

• ArcGIS Desktop ApplicationsArcGIS Desktop Applications

• ArcIMS , ArcExplorer, ArcPadArcIMS , ArcExplorer, ArcPad

• MapObjects MapObjects

• Third-Party applicationsThird-Party applications

SQL ServerSQL Server OracleOracle InformixInformix IBM DB2IBM DB2

ArcSDE Services

ArcSDEArcSDE

Data Is Independent of Application

ArcIMSArcIMSArcGISArcGIS

SQL ServerSQL ServerSQL ServerSQL Server

High Availability, High Performance, Secure, Scalable

Web Server

DatabasesDatabases

BrokerBroker

BrowsersBrowsers

Web

ApplicationsApplications

Web Server

DatabasesDatabases

BrokerBroker

BrowsersBrowsers

Web

ApplicationsApplications

ServicesServices

Distributed GIS DevelopmentDistributed GIS Development

New Concept – g.net architecture leveraging emerging web technologies

Web services GIS technology for applications over the web

Mapping Metadata GIS Functionality

Spatial Data sharing and distribution

Extends ArcGIS System concept Desktop Applications Back Office Servers Distributed “Services” via the Internet

GIS Portal

GIS Portal

• Network architecture

(Distributed)

• Loosely Coupled

• Internet Standards

• Many GeoServices

• Many Clients

• Metadata Servers

• Open / Interoperable

• Full GIS capabilities

GIS Users

GIS PortalMetadata

Server

Searc

h Cat

alog

and

Fin

d

Searc

h Cat

alog

and

Fin

d

Publish GIS Data & ServicesPublish GIS Data & Services

Document in CatalogDocument in Catalog

Connect and U

se

Connect and U

se

Checkout and U

se

Checkout and U

se

World Wide Web

Author, Manage, Serve Geographic Information Collections

Author, Manage, Serve Catalogs

GIS GIS ClientsClients

GIS GIS ClientsClients

GIS Web GIS Web ServicesServices

GIS Web GIS Web ServicesServices

ArcGIS

Used to build

• Data

• Maps

• Models

• Applications

• Metadata

ArcGIS

Used to build

• Data

• Maps

• Models

• Applications

• Metadata

ArcIMS

• Serve GIS

• Data

• Maps

• Apps

ArcIMS

• Serve GIS

• Data

• Maps

• Apps

ArcGIS

• Author and Manage

Metadata

• Build Catalog

ArcGIS

• Author and Manage

Metadata

• Build Catalog

Array of GIS Clients

Access and use GIS data and services

• ArcReader

• Map Objects for Java

• ArcGIS Desktop & Extensions

• ArcPad

Array of GIS Clients

Access and use GIS data and services

• ArcReader

• Map Objects for Java

• ArcGIS Desktop & Extensions

• ArcPad

ArcSDE

Used to manage

• Data

• Metadata

• Transactions

ArcSDE

Used to manage

• Data

• Metadata

• Transactions

ArcSDE

Used to manage and distribute

• Metadata

ArcSDE

Used to manage and distribute

• Metadata

ArcIMS

• Manage Metadata

• Provide Search Services

ArcIMS

• Manage Metadata

• Provide Search Services

MetadatMetadata & a &

Catalog Catalog ServicesServices

MetadatMetadata & a &

Catalog Catalog ServicesServices

3-Stages of GISData preparation and entry: the early stage in

which data about the study phenomenon is collected and prepared to be entered into the system.

Data Analysis: the middle stage in which collected data is carefully reviewed and, for instance, attempts are made to discover patterns

Data Presentation: the final stage in which the results of earlier analysis are presented in an appropriate way

Importance & ApplicationsB: BusinessI: IndustriesG: GovernmentA: AcademyA: AircraftM: Military

Major AreaNatural Resource Management

Wildlife habitat, Wild and scenic rivers, Recreation resources, Floodplains, Wetlands, Agricultural lands, Forests.

Facilities ManagementLocating underground pipes and cables, Balancing loads in electrical networks, Planning facility maintenance

Application contd…Land Management

Zoning and subdivision planning, Land acquisition, Environmental impact policy, Water quality management, Maintenance of ownership.

Info. Based Street NetworkAddress matching, Location analysis or site selection, Development of evacuation plans.

How GIS assume Greater SignificanceWhich is the best route between kalanki and ratnapark

having minimal road intersection with good road and lesser traffic jam during peak hours?

Identify the roads served by Metro water tank in kalanki with a population between 1,000 and 1,500?

Which part of Gandaki zone has less literacy rate with unemployed youth between 20 and 30 years of age?

Where are the potential aquifers located away from agricultural land with good road connectivity within 50 km of Kathmandu for groundwater extraction?

Identify the apartment houses in new road not following building codes to withstand earthquake.

Spatial data and Geoinformationspatial data; we mean data that contains

positional values. Often we can say in more precise phrase geospatial data as a further refinement, which then means spatial data that is geo-referenced

By information, we mean data that has been interpreted by a human being

Geo-information is a specific type of information that involves the interpretation of spatial data.

The real world and representation of GISwe usually are trying to represent some part of the

real world as it is, as it was, or perhaps as we think it will be

A computerized system can help to store such representations.

Static ModelMaps & Databases: at any point in time, they represent a

single state of affairs. Usually developments or changes in the real world are not easily recognized in these models.

Dynamic ModelSimulation

Maps..The best known models of the real world are maps

A map is a miniature representation of some part of the real world

GIS and the map is very closely related to each other

maps can deal with questions/answers relating to basic components of spatial or geographic data: location (geometry), characteristics, (thematic attributes) and time, and their combinations

Map TypesTopographic maps: A topographic map

visualizes, limited by its scale, the Earth’s surface as accurately as possible. This may include infrastructure (egg, railroads and roads), land use (eg, vegetation and built-up areas), relief, hydrology, geographic names and reference grid

Thematic maps: A thematic map represents the distribution of the particular themes; we can distinguish socio-economic theme and the physical themes using these maps.

Spatial Databases A spatial database system is a database system

It offers spatial data types in its data model and query language

It supports spatial data types in its implementation, providing at least spatial indexing and efficient algorithms for spatial join.

a spatial database is a collection of spatially referenced data that acts as a model of reality -a database is a model of reality in the sense that the database represents a selected set or approximation of phenomena -these selected phenomena are deemed important enough to represent in digital form -the digital representation might be for some past, present or future time period (or contain some combination of several time periods in an organized fashion)

Spatial Databases…Spatial DB store representations of geographic

phenomena in the real world to be used in a GIS.

They are special in the sense that they use other techniques that tables to store these representations because it is not easy to represent geographic phenomena using tables.

spatial phenomena exist in a two or three dimensional Euclidean space ( a model of space in which locations are represented as coordinates- (x, y) in 2D; (x, y, z) in 3D- and notions like distance and direction have been defined with the usual formulas).

Spatial DB..A database may contain collection of: