Download - Getting started with GIS
Getting started with
G S
Submitted by:
Pattan Imran Khan
IntroductionGeographical Information System
The acronym GIS stands for Geographical
Information System.
GIS consists of two distinct disciplines,
namely, Geography and Information System.
GISGeography Information system
&
What is Geography?
The scientific study of the geospatial pattern
and process.
The geography usually starts with 3 “W’s”
questions :1. Where?2. What is it like there?3. Why do I care?
What is Information
System?
It is an interactive combination of people,
computer hardware and software, communication
devices and procedures designed to provide
continuous flow of information to the people who
need information to make decisions or perform
analysis.
What is a GIS?
A geographical information system is a system
which integrates hardware, software and data
for capturing, managing, analyzing and
visualizing all forms of geographically
referenced information.
In simplest terms it is the merging of
cartography, statistical analysis and database
technology.
In short, a GIS is….
An information system (hardware, software, data)
which enables us to apply lots of analysis models
to any geographical datasets
for generating derived information
that can be visualized as maps.
History & Development of GIS: The development of GIS was first started in 1832. One of the
first applications of spatial analysis is in Epidemiology.
In 1854 John Snow depicted a cholera outbreak in London
using points to represent the locations of some individual
cases, possibly the earliest use of a geographic methodology
in epidemiology.
The year 1960 saw the development of the world’s first true
operational GIS in Ottawa, Ontario, Canada by the federal
dept. of forestry and rural development, developed by
Dr. Roger Tomlinson (Father of GIS),
it was called the Canada Geographic Information System (CGIS).
London Cholera epidemic(1854):
Cholera death
Water pump
Key components of GIS: A GIS constitutes of five key components, namely
1. Documentation
2. Hardware
3. Software
4. Data and
5. Users.
These five components need to be in balance to
function any information system satisfactorily.
GIS
Software
Data
Documentation
Users
Hardware
• Vector(Drawing)• Raster(images)• Descriptive(text/tables)
• Guides• Procedures• Specifications• Standards
• End Users• Administration
• Managers• GIS Technicians
• Computer & Peripherals
• Networks and network devices• Printing and
image acquisition
devices
• GIS applications• databases• operating system• other software's
GIS data & Spatial data model:
Data are the observations made from real-world
experiences, organized and processed in order to
make them meaningful, and convert into
information.
Data may have three modes:
1. Spatial data
2. Thematic or attribute or non-spatial data &
3. Temporal data.
Spatial data may be represented by several GIS data
models.
Data model:
A data model describes in an abstract way how data
is represented in an information system.
In GIS there are two basic data models to input and
visualize data in the world of GIS. They are:
1. Raster data model &
2. Vector data model.
Raster data model: The raster data model divides the geographic space into a
regular grid of square cells, called pixels, with a number in
each cell representing the solid color fill of that cell in
specific sequence (row-column structure).
Example of raster data may be:
Stored electronic image or
picture taken as an aerial
photograph or satellite image.
Vector data model: The vector data model is close to the traditional
mapping approach where the objects are
represented as points, lines or areas(features).
The position of each object is defined by a series of
coordinate pairs.
Points
Lines
Areaspoint
1,6
2,5
5,4
4,1
7,105,9
4,7
6,68,6
9,8
line
polygon
2,2
5 10
5
10
Vector model Raster model
Capture Analyze
Manage Present
GIS Process
Global positioning system (G.P.S)
Step 1: Capture
Remote sensing
Active
Passive
Step 1: Capture
Photogrammetric techniques
Step 1: Capture
Examples :
ArcGIS QGIS MapInfo
Step 2 : Analyze
DataBases
Step 3 : Manage
Examples :
PostGIS
MySQL Oracle
Step 3 : Manage
Printed Maps
Dynamic or Interactive Maps
Step 4 : Present
GIS Applications
Applications of GIS: Agriculture
Archaeology
Business
Crime mapping
Environmental science
Engineering
Journalism
Military science
Natural resource
management
Geography
Geology
Meteorology
Oceanography
Law enforcement
Public health
History
Sociology
Urban/Regional planning
Transportation
Thank You