lodha govardhan

well come to all

Govardhan LodhaB.Sc.(Ag.) Final Year

J. N. Agriculture University, Jabalpur College of Agriculture, Tikamgarh (M.P.)

GIS Operation and Data Formation in GIS

Image: NASA 2005

GOVARDHAN LODHAAKASH SONKUSALE

SUBMITTED TO :-

Dr. M. L. KewatAssociate Professor

PRESENTED BY :-

PRESENTATION ON

JAWAHARLAL NEHRU KRISHI VISHWA VIDHYALAYA JABALPUR M.P.

College of Agriculture, Jabalpur

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

What is GIS?

1

Geographic Information System• Geographic – 80% of government data collected is

associated with some location in space

• Information - attributes, or thecharacteristics (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!

• 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 -

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

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 data2. Raster data:

Types of Spatial data• Vector For discrete data represented as

• Points• Lines• Polygons (zones or areas)• A series of x y coordinates

• Raster • Grid and cells• For continuous data such as elevation, slope,

surfaces

A Desktop GIS should be able to handle both types of data effectively!

Raster

Vector

Real World

Data Representation

• 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

GIS provides Data Integration

VectorsTopology

Networks

Terrain

Surveys

Images

CADDrawings

Annotation

Addresses

27 Main St.

Attributes

ABC

107’

3D Objects

Dimensions• Roads• Land Parcels• Population• Utilities• Land Mines• Hospitals• Refugee Camps• Wells• Sanitation

Working with GIS

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

Generate Image of Real world -

Data on different themes are stored in separate “layers”.

As each layer is geo-referenced layers from different sources can easily be integrated using location.

This can be used to build up complex models of the real world from widely disparate sources.

An overview of a GIS 3D image -

Questions

Thank You !