This document provides an overview of geographic information systems (GIS). It defines GIS as a system that links geographic data to locational information. It explains that GIS has both spatial and attribute data and can represent data as vectors or rasters. The document also gives examples of how GIS is used in various applications like environmental assessment, resource management, and transportation routing. It provides a brief description of how GIS works by storing data in thematic layers that can be linked by location. It also outlines some key GIS operations like data capture, geo-referencing, and data representation.

1. B.Sc.(Ag.) Final Year
J. N. Agriculture University, Jabalpur
College of Agriculture, Tikamgarh (M.P.)

2. Image: NASA 2005
GOVARDHAN LODHA
AKASH SONKUSALE
SUBMITTED TO :-
Dr. M. L. Kewat
Associate Professor
PRESENTED BY :-

3. Slides
• Introduction
• GIS Operations
• How does GIS work?
• Types of data
• Data Representation
• Working with GIS
• An overview of GIS Image

4. What is GIS?
1

5. Geographic Information System
• Geographic – 80% of government data collected is associated
with some location in space
• Information - attributes, or the
characteristics (data), can be used to symbolize and provide
further insight into a given location
• System – a seamless operation linking the information to the
geography – which requires hardware, networks, software,
data, and operational procedures
…not just software!
…not just for making maps!

6. • Many More to Come…
 Environmental impact assessment
 Resource management
 Land use planning
 Tax Mapping
 Water and Sanitation Mapping
 Transportation routing
 And many more ...
GIS Operations -

7. How does a GIS work?
• GIS data has a spatial/geographic
reference
 This might be a reference that describes a
feature on the earth using:
• a latitude & longitude
• a national coordinate system
• an address
• a district
• a wetland identifier
• a road name

8. Types of data
 Two types of data are stored for each item in the
database
• 1. Attribute data:
 Says what a feature is
• Eg. statistics, text, images, sound, etc.
• 2. Spatial data:
 Says where the feature is
 This also of two types -
1. Vector data
2. Raster data:

9. Types of Spatial data

10. Raster
Vector
Real World
Data Representation

11. • A GIS stores information about the world as a
collection of thematic layers that can be linked
together by geography
Polygon 3 Scrub 17 Very high Clay
Geography and Databases

12. GIS provides Data Integration
Vectors
Topology
Networks
Terrain
Surveys
Images
CAD
Drawings
Annotation
Addresses
27 Main St.
Attributes
ABC
107’
3D Objects
Dimensions
• Roads
• Land Parcels
• Population
• Utilities
• Land Mines
• Hospitals
• Refugee Camps
• Wells
• Sanitation

14. Data formation in GIS
 Capturing data
 Scanning: all of map converted into raster data
 Digitising: individual features selected from map as
points, lines or polygons
 Geo-referencing
 Initial scanning digitising gives co-ordinates in inches
from bottom left corner of digitiser/scanner
 Real-world co-ordinates are found for few
registration points on the captured data
 These are used to convert the entire map onto a
real-world co-ordinate system

15. Generate Image of Real world -

16. An overview of a GIS 3D image -

18. Thank You !