Babu Ram Dawadi, IOE Pulchowk Campus
Definition
 A 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 location
 information– visualization of analysis of data
 system– linking software, hardware, data
 personnel– a thinking explorer who is key to the power
of GIS
History of GIS
Decade
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 GIS
Decade
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 GIS
Decade
Milestones for computer-based GIS
1990’s
- MapInfo for Windows, Intergraph, Autodesk, others
- ESRI produces ArcView and ARCGIS
- $7+ billion industry
GIS Software
 The geoprocessing engines of GIS
 Major functions
 Collect, store, mange, query, analyze and present
 Key terms
 Program – collections of instructions to manipulate data
 Package – integrated collection of programs
 Component – self-contained, reusable software building
blocks
Functionality Architecture
User Interface Applications
Output
Analysis
Translation
Geographic Tools
Editing
Spatial
Reference
Customization
Display
Data
Manager
Data Access
Vector
Raster
Product Families
Autodesk
ESRI
Intergraph
MapInfo
Smallworld
GeoMedia Viewer
ProViewer
Custom
MapInfo
Professional
MapInfo
Professional
Spatial
Intelligence
Smallworld GIS
Viewer
AutoCAD
LT
Desktop
World
ArcView
GeoMedia
Professional
AutoCAD /
Map
ArcEditor
GeoMedia Pro
Hand-held
OnSite
ArcPad
IntelliWhere
MapXtend
Scout
Database
Server
GIS
Server
ArcSDE
Uses Oracle
Spatial
SpatialWare
Part of
Smallworld GIS
Component
In several
products
Map
Objects
Part of GeoMedia
MapX, MapJ
Part of
Smallworld GIS
Internet
MapGuide
ArcIMS
MapXtreme,
MapXSite
CAD
AutoCAD
Map
In several
products
GeoMedia Web
Map, GeoMedia
Web Enterprise
In several
products
Smallworld
Internet Application Server
Part of
Smallworld GIS
ArcReader
ArcInfo
In several
products
GIS Software Classification
Number of
Users
Internet
Viewer
Component
Hand-held
Desktop
Professional
Functionality
Cost
ArcSDE Unifies Spatial Data Access
• ArcGIS Desktop Applications
• ArcIMS , ArcExplorer, ArcPad
• MapObjects
ArcSDE Services
SQL Server
Oracle
• Third-Party applications
Informix
IBM DB2
First, Spatially Enable The Data…
Data Is Independent of Application
ArcSDE
ArcIMS
ArcGIS
SQL Server
High Availability, High Performance, Secure, Scalable
GIS Internet Enterprise Today
Applications
Browsers
Web
Web Server
Broker
Databases
Future GIS Internet Enterprise
Applications
Browsers
Web
Web Server
Broker
Services
Databases
Distributed 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
G.net Architecture Building Blocks
• Network architecture
(Distributed)
GIS
Users
• Loosely Coupled
• Internet Standards
• Many GeoServices
• Many Clients
World
Wide Web
• Metadata Servers
• Open / Interoperable
• Full GIS capabilities
Metadata
Server
 Publish GIS Data & Services
 Document in Catalog
Author, Manage, Serve
Catalogs
GIS
GIS
Portal
GIS
Portal
Portal
Author, Manage, Serve
Geographic Information Collections
ESRI Direction
“Software for G.Net”
ArcGIS
ArcIMS
Used to build
• Serve GIS
GIS Web
Services
• Data
• Maps
• Data
• Maps
• Models
• Apps
• Applications
Array of GIS Clients
Access and use GIS data
and services
• ArcReader
• Map Objects for Java
• Metadata
ArcSDE
ArcGIS
Used to manage
• ArcGIS Desktop &
Extensions
• Author and Manage
Metadata
• Data
• ArcPad
• Build Catalog
ArcSDE
Used to manage
and distribute
• Metadata
Metadata
&
Catalog
Services
• Metadata
• Transactions
ArcIMS
• Manage Metadata
• Provide Search
Services
GIS
Clients
3-Stages of GIS
 Data 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 & Applications
 B: Business
 I: Industries
 G: Government
 A: Academy
 A: Aircraft
 M: Military
Major Area
 Natural Resource Management
 Wildlife habitat,
 Wild and scenic rivers,
 Recreation resources,
 Floodplains,
 Wetlands,
 Agricultural lands,
 Forests.
 Facilities Management
 Locating 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 Network
 Address matching,
 Location analysis or site selection,
 Development of evacuation plans.
How GIS assume Greater Significance
 Which 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 Geoinformation
 spatial 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 GIS
 we 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 Model
 Maps & 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 Model
 Simulation
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 Types
 Topographic 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: