Geographic Information System

1. GEOGRAPHIC INFORMATION
SYSTEM

2. Learning outcomes
1. GIS Disciplines
2. Understand why geography matters
3. Location- allocation
4. Mapping Concepts
5. Parts of maps

3. GIS used in multiple disciplines:
• Agriculture
• Archaeology Architecture/Landscape
Arch.
• Business
• Computer Science
• Environmental Science
• Engineering Journalism
• Military Science
• Natural Resource Management
• Geography Geology
• Meteorology
• Oceanography Law
• Enforcement Public
• Health History
• Sociology
• Urban/Regional Planning

4. Agriculture
• Farm management
• Pest/Disease tracking
• Crop monitoring
• Yield prediction
• Soil analysis

5. Natural Resource
Management
• Forestry
• Ecology
• Mining
• Petroleum
• Water Resources

6. Planning and Economic
Development
• Land Use/Zoning
• Emergency Preparedness
• Population Forecast
• Market Analysis
• Property Tax Assessment
• Transportation

7. Geography matters
Today’s challenges require geographic approach. Location matters for
understanding a wide variety of processes and phenomena. It helps us to have
an awareness of a place. All places and spaces have a history behind them,
shaped by humans, earth, and climate.
• Climate Change
• Urban Growth
• Sustainable Agriculture Water Quality and Availability
• International and National Security
• Energy
• Epidemiology/Disease Tracking
• Natural Hazards: Seismicity, Weather Events

8. Location- Allocation
• Finding a subset of locations from a set of potential or
candidate locations that best serve some existing
demand so as minimize some cost
• Locate sites to best serve allocated demand
• Application areas are warehouse location, fast
food locations, fire stations and schools.

9. Location- Allocation Inputs
• Customer or demand locations
• Potential site locations and/or existing facilities
• Street network
• The problem to solve

10. Location- Allocation Outputs
• The best sites
• The optimal allocation of demand locations to those
sites
• Lots of statistical and summary information about that
particular allocation

11. Maps and Maps Elements

12. Mapping Concepts
A map is a two-dimensional representation of
earth surface which uses graphics to convey
geographical information. It describes the
geographical location of features and the relationship
between them.

13. Mapping Concepts
Maps provide two types of information
o Locational information - means and include the geo-information obtained
through GPS or other means, such as the geographical location of the User and
sensor data from the device on which you access the Services.
o Spatial Relationships - explore the concept of where objects are in relationship
to something else. For example, a ball may be behind the chair, or under the
table, or in the box. The dog may be on the blanket, outside of the house, or in
the doghouse.

14. Mapping Concepts
Maps contain POINT, LINE and AREA features
• Point Features : wells, control points, sample sites, fire
stations
• Line Features : roads, hydro lines, rivers, contour lines.
• Area Features: urban areas, water bodies, soil/rock units,
forest areas

15. Point Features
o can be used to represent the location of any number of real-world
features. These include the ff:
o soil samples
o Manholes
o pumping stations,
o Trees
o Buildings
o Traffic accident
o Lamp post

16. Points
Examples: Wells, sample sites, huts, schools, clinics

17. Line Features
o Lines are a series of geographic coordinates joined
to form a line such as:
o Road
o Stream
o Railway

18. Lines
Examples: Roads, rivers, powerlines, faults
Simple
Complex
Curves
Networks

19. Area Features
o Areas (Polygons) are a series of geographic coordinates
joined together to form a boundary such as:
o Lake
o Farm
o Forest
o Soil types

20. Polygons

21. 5 Basic parts of any maps
Every map is unique, but most have at least five main
components in common:
1. Map Title or Heading
2. Map Key or Legend
3. Scale Indicator
4. Grid
5. Compass Rose or North Arrow

22. Map of the Philippines

23. Map Title or Heading
The title, also called the heading, of a map is
typically found at the top of the map. It tells you
exactly what the map is showing. The title will be in
a large font and describe in detail what the map is
for.

24. Map Key or Legend
All the map symbols are defined in the map key, or map legend.
The terms “key” and “legend” are often used interchangeably,
but some maps have both a key and a legend. In these instances,
the key includes the symbols while the legend includes things
like the scale and compass rose.

25. The symbols on a map make it easier to read because the map is
not crowded with words. The key is usually off to the side of the
map and tells you what each symbol stands for.
Map Key or Legend

26. Map Key Symbols
When making a map, Cartographers (map makers)
cannot write out everything and make it fit. They
need quick, simple drawings, called map symbols,
to replace written information. If you do not know
what ⋅⋅, ∘∘, or ⊙⊙ means, you cannot understand
the map.

27. Map Key Symbols
A map key tells you what all the symbols on the
map mean. For example, the small black dot, ⋅⋅,
means a town or village, the open circle, ∘∘, means
a city of at least 75,000 people or that ⊙⊙ means
a state capital. A map key can tell you that ★
usually shows a country’s capital.

28. Map Key Symbols
Every map uses its own map symbols, depending
on the information the cartographer wants to show.
Map keys can show symbols for natural resources,
population centers, bodies of water, types of
industry, and much more.

29. Map Key

30. Map Key Example

31. Map Key Example

32. Scale Indicator
The size of earth is too big to be represented as it is on a map. To
represent the whole earth or part thereof on a small map, the concept
of scale is used.
Representation of Scale:
1. Statement: Expressed in words such as ‘1 centimeter to the
kilometer’ which means one centimeter on the map represents one
kilometer on the ground.

33. 2. Representative fraction: It is expressed in fraction. If the scale is
1:50000, it means that 1 unit of measurement on map
represents 50,000 units on ground. It is also known as
numerical scale.
3. Graphic: The scale is shown in form of a strip, where the strip is
divided into a number of equal parts and is marked to show what
these divisions represent on actual ground. It is also known as
plain scale or linear scale.
Scale Indicator

34. Scale Indicator

35. Grid
A map’s grid is a series of imaginary horizontal and
vertical lines drawn onto the map. These lines may
represent actual latitudes and longitudes or they may just
split the map into smaller parts. Grid lines will be labeled
at one end or each end.

36. Grid

37. Compass Rose or North Arrow
A compass rose is a symbol on a map
that shows the cardinal directions. The
cardinal directions are the main compass
points—north, south, east, and west.
Sometimes it tells the intermediate or
ordinal directions, too: northeast,
southwest, northwest, southwest.

38. The orientation of a map is important to know, so a tool
that shows you the cardinal directions, or at least which
way is north, is included on most maps. You may see
an arrow labeled “N” for north, or you may see a
compass rose. A compass rose looks like a big star and
shows north, south, east, and west.
Compass Rose or North Arrow

39. Compass Rose or North Arrow

40. Compass vs. Compass Rose
A compass is a tool that can tell you what direction
you are going, and a compass rose is a drawing on
a map that tells you the directions of places shown
on the map.

41. Compass Rose
On maps and nautical charts dealing with tides,
sailing, and coastlines, the compass rose is also
called a "windrose" or "rose of the winds."

42. Other Common Parts of a Map
Because each map is unique, it’s hard to identify
the basic parts that appear on every single map.
You may see examples of the three main parts of a
map or even five, six, or eight main components of
a map.

43. Additional common map parts include:
• border or neatline - a thick line showing where the map stops
• map credits - information about who made the map, when it
was made, or the data was used to make it
• locator map or inset - a zoomed in or zoomed out view of an
area represented on the map