Presentation on GIS

8/6/2019 Presentation on GIS

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SUBMITTED TO- SUBMITTED BY-

Mrs. Rachna Jain Ajay MakvanaAmit Kumawat

Anveshak Pardhi


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A system for capturing, storing, checking,

integrating, manipulating, analysing and

displaying data which are spatially

referenced to the Earth. This is normallyconsidered to involve a spatially referenced

computer database and appropriate

applications software

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GIS handles SPATIAL information

Information referenced by its location in space

GIS makes connections between activities

based on spatial proximity

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DigitalDigital

MappingMapping

PhotoPhoto--

grammetrygrammetry

ComputerComputer

AidedAided

DesignDesign

SurveyingSurveying

RemoteRemote

SensingSensing

DatabasesDatabases

GISGIS

Cross-disciplinary nature of GIS


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PlacenamePlacenameGrid coGrid co--ordinateordinate

PostcodePostcode

Distance & bearingDistance & bearing

DescriptionDescription

Latitude / LongitudeLatitude / Longitude


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Geometry

The shape of a

building or county

The course of a

river, the route of a

roadThe shape of the

landscape, relief

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Socio-economic data

Regional health data

Consumer / lifestyle profiles

Geodemographics

Environmental data

Topographic data

Thematic data, soils, geology

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Data Modelling - step 1 Features

Buildings

Road centrelines

Lamp columns

Gas pipes

CTV Access covers

Road surfaces


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Point

Line

Polygon


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Feature: Building

Object: PolygonEntity: Tourist

Information

Bureau


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Vector model

Raster model

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point

1,6

2,5

5,4

4,1

7,105,9

4,7

6,6

8,6

9,8

line

polygon

2,2

5 10

5

10

as geometric objects:

points, lines, polygons

as image filescomposed of grid-cells

(pixels)


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Advantage of the vector data format: allows precise

representation of points, boundaries, and linear

features.

useful for analysis tasks that require accuratepositioning,

for defining spatial relationship between coverage

features (topology), important for such purposes as

network analysis.

Main disadvantage of vector data is that the boundaries

of the resulting map polygons are discrete (enclosed by

well-defined boundary lines), whereas in reality the

map polygons may represent continuous gradation or

gradual change, as in soil maps.


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Good for representing indistinct boundaries

thematic information on soil types, soil

moisture, vegetation, ground temperatures.

As reconnaissance satellites and aerial surveys

use raster-based scanners, the information (i.e;

scanned images) can be directly incorporatedinto GIS.

The higher the grid resolution, the larger the

data file is going to be


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1 1 20 50

1 2 24 45

1 3 52 55

2 1 0 45 46

40

...

0 0 0 0 0 0 0 2 0

0 0 0 0 0 1 0 0 0

0 2 0 0 1 0 0 0 0

0 0 0 0 2 0 0 0 0

2 2 2 0 1 ...

x

y


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Geo-relational Data Models

Linked tables based on the relational

model, but storing geographical

information such as:

Geometry

Topology

Attributes


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Better information management

Higher quality analysis

Improve project efficiency

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Facilities management

Marketing and retailing

Environmental

Transport/vehicle routing

Health

Insurance

and many more . . .

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GIS is frequently confused with GPS because it is amore generic acronym (Geographic InformationSystem) used to describe a more complex mappingtechnology that is connected to a particular

database.

Because its generic, it is a broader term than theGPS in its technical sense.

Thus, GIS is a computer program or application thatis utilized to view and handle data about geographiclocations and spatial correlations among others. Itsimply gives the user a framework to obtaininformation.


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Documents

Presentation on GIS