Basic introduction about GIS and Remote Sensing

1. Introduction toIntroduction to
Geographic InformationGeographic Information
Systems (GIS)Systems (GIS)
&&
Remote Sensing (RS)Remote Sensing (RS)
Syed Subtain HussainSyed Subtain Hussain
GIS ConsultantGIS Consultant
20182018

2. OutlinesOutlines
• Introduction to GIS
• Who use GIS? & what can we do with
GIS
• How does GIS work?
• Geography database & types of data
• Features of GIS
• Remote Sensing (RS)
• Sample Maps

3. What is GIS?
11

4. Geographic Information System (GIS) is a
computer-based system including software,
hardware, people, and geographic information
A GIS can:
create, edit, query, analyze, and display
map information on the computer
A “geographic information system” (GIS) is a
computer-based tool that allows you to create,
manipulate, analyze, store and display
information based on its location.

5. Geographic Information SystemGeographic Information System

6. Who uses GIS?Who uses GIS?
• International organizations
 The World Bank, UN, FAO, WHO, etc.
• Private industry
 Transport, Real Estate, Insurance, Crime, etc.
• Government
 Ministries of Environment, Housing, Agriculture,
Census, NDMA, etc.
 Local Authorities, Cities, Municipalities, etc.
 Provincial Agencies for Planning, Parks,
Transportation, etc.

7. GIS SoftwarsGIS Softwars
• Esri ArcGIS desktop/server
• MapInfo
• Global Mapper
• QGIS (opensource)
• Etc.

8. • The possibilities are unlimited…
 Environmental impact assessment
 Resource management
 Risk Assessment
 Disaster Management
 Tax Mapping
 Water and Sanitation Mapping
 Transportation routing
 Disaster planning
 and more ...
What can you do with a GIS?What can you do with a GIS?

9. How does a GIS work?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
• A land parcel
• Etc.

10. What is Spatial Data?What is Spatial Data?
Spatial data is information
which is linked to a specific
location, for example the
population of a town, or the
occupant of an address.

11. • A GIS stores information about the world as
a collection of thematic layers that can be
linked together by geography
Geography and DatabasesGeography and Databases

12. Data Collection TechniquesData Collection Techniques
RasterRaster VectorVector
PrimaryPrimary Digital remote
sensing images
GPS
measurements
Digital aerial
photographs
Survey
measurements
SecondarySecondary Scanned maps Topographic
surveys
DEMs from maps Data sets from
atlases

13. GIS WORK FLOWGIS WORK FLOW

14. GIS providesGIS provides Data IntegrationData Integration
VectorsVectors
TopologyTopology
NetworksNetworks
TerrainTerrain
SurveysSurveys
ImagesImages
CADCAD
DrawingsDrawings
AnnotationAnnotation
AddressesAddresses
27 Main St.27 Main St.
AttributesAttributes
ABCABC
107’107’
3D Objects3D Objects
DimensionsDimensions
• Roads
• Land Parcels
• Population
• Utilities
• Land Parcel
• Land Mines
• Hospitals
• Refugee Camps
• Wells
• Sanitation
• etc.

15. Two fundamental types of dataTwo fundamental types of data
• Vector
 A series of x,y coordinates
 For discrete data represented as points, lines,
polygons
• 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!

16. Raster
Vector
Real World
Data RepresentationData Representation

17. Sample MapSample Map
Land useLand use

18. Sample MapSample Map
Land Parcel of VillageLand Parcel of Village

19. Remote Sensing (RS)Remote Sensing (RS)
• Remote Sensing, process of obtaining information about
land, water, or an object without any physical contact
between the sensor and the subject of analysis.
• Remote Sensing is an extensive science, drawing from
many areas for support and development. Satellite and
digital imagery play an important role in remote sensing;
providing information about the land studied.
• The benefits of remote sensing continue to arise. It can
be used to access hard to reach areas for fieldwork, and
provides a more detailed, permanent and objective
survey that offers a different perspective. Air photos are
still favored and easily accessible sources of information
for classification

20. RS acquiring informationRS acquiring information
• Remote Sensing means acquiring
information about a phenomena,
object or surface while at a
distance from it. This name is
attributed to recent technology
in which Satellite, space craft
and Drone are used from
collecting information to it.

21. The remote sensing processThe remote sensing process

22. Higher Resolution Satellite Sensors UsedHigher Resolution Satellite Sensors Used
Quickbird
2.5 m multispectral
resolution
61 cm (~2 ft.)
panchromatic resolution
IKONOS
4 m visible/infrared
resolution
1 m panchromatic
resolution
MOST COMMON USES FOR HIGH RESOLUTION:MOST COMMON USES FOR HIGH RESOLUTION:
Accurate Base Maps
Infrastructure Mapping
Disaster Assessment (Smaller Scale)

23. How data is extracted:How data is extracted:
• Layers such as roads (yellow) and rivers (blue) can
be easily seen from air/satellite photos
• This information is digitized (see next slide),
separated into layers, and integrated into a GIS

24. Digitizing DataDigitizing Data
• MANUALMANUAL
 Map is fixed to digitizer table
 Control Points are digitized
 Feature Boundaries are digitized in stream or point mode
 The layer is proofed and edited
 The layer is transformed/registered to a known system
• AUTOMATED SCANNERSAUTOMATED SCANNERS
 Digitizing done automatically by a scanner
 There is a range of scanner qualities
 Most utilize the reflection/transmission of light to record data
 “Thresholding” allows for the determination of both line and point
features from a hardcopy map
 Editing still required
• DIRECT DATA ENTRYDIRECT DATA ENTRY
 Coordinate Geometry is used, with GPS playing a vital role
 This involves directly entering in coordinates measured in the field
 These coordinates can then be tagged with attribute data
 This data this then downloaded to a computer and incorporated into a
GIS

25. IKONOS (4 m Multispectral)IKONOS (4 m Multispectral)

26. Pre Flood – 17 July 2006 Post Flood – 09 Aug 2006
10098 acr
3516 acr
● Phulani
● Goth Lataran
● Ural
● Junno Dhand
● Shahpur
● Godhpur
● Than Lake
● Goth Azizpur
● Goth Raza Mahar
● Phulani
● Goth Lataran
● Ural
● Junno Dhand
● Shahpur
● Godhpur
● Than Lake
● Goth Azizpur
● Goth Raza Mahar
● Muhro Mari
● Darapur
● Kot Shahgarch
● Muhro Mari
● Darapur
● Kot Shahgarch
Flood Damage to Standing CropsFlood Damage to Standing Crops
SukkurSukkur

27. Village 21
Village 13
Village 20
Village 11
Village 22
Village 19
Village 15
Village 14
Village 16
Village 7
Village 23
Village 17
Village 8
Village 5
Village 3
Village 2
Village 1
Village 12
Village 9
Village 6
Village 10
Village 4
Village 18
Village 24
MODELLING THROUGH GISMODELLING THROUGH GIS
VILLAGES TO BE EFFECTED BY FLOODINGVILLAGES TO BE EFFECTED BY FLOODING
If flood level rose to 2000 feet
If flood level rose to 3000 feet
If flood level rose to 4000 feet

28. Thank You!Thank You!