Geograhic
Information System
Sodik Kirono
Muhadi Setiabudi University
March, 3rd 2020
INTRODUCTION TO
GEOGRAHIC
INFORMATION
SYSTEM
Kang-Tsung Chang. 2006. Introduction to
Geographic Information Systems, 4th Edition.
New York : Mc Graw Hill [Chapter 1]
Longley et al., GI Systems & Science, VR 100
Preface, Chapter 1
1.2 Brief Story
What is GIS?
GIS Basics
Concepts
GIS
Applications
Component of
GIS
1.1. Whats is
GIS?
GIS Basics Concepts
Mapping is key but is NOT the whole story
A GIS is NOT simply for MAKING
maps
maps at different scales, projections, colors
… not simply for STORING maps or
images.
In fact, it stores the DATA from which these
are created.
Container of data
Container of maps
Geographic
Information
System
Inventory of geographically distributed features and facilities
Computerized tool to automate time-consuming tasks
Analysis tools for solving geographic problems
Spatial decision support system
Method for revealing patterns and processes in geographic
information
Geographic
Information
System
Software
Hardware
Network
Data
People
Procedures
What exists at a certain location?
Where are certain conditions satisfied?
Major
Questions for
a GIS?
What has changed in a place over time?
What spatial patterns exist?
What if this condition occurred at this place?
(modelling, hypothesis testing)
The Process of GIS
Think about a
place or a
topic ...
Ask a question
about it ...
Analyze data
to make a
map ...
Explore the
patterns that
appear ...
Enhance the
data or modify
the analysis ...
Ask a new
question …
Repeat ...
GIS Definitions
Different definitions of a GIS have evolved in
different areas and disciplines.
• map coordinates,
• Database of spatial and often non-spatial,
• computer-based link between them.
All GIS definitions recognize that spatial data
are unique because they are linked to maps.
Spatial Data
Attribute Data
Joining Spatial and
Attribute Data
1.3 Geospatial Data
Spatial/Geospatial/Geographic
Data?
Latitude and
longitude
Street address
x and y
coordinates
Range and
township
Location shown
on a map
Non-spatial Data?
Name
Gender
Income
SSN or student ID number
Political party
Data Model
A conceptual description (mental
model) of how spatial data are
organized for use by the GIS
GISs have traditionally used
either “field” or “object” data
models
A Field Data Model Uses a Raster or Grid
Data Structure.
Grid extent
Rows
Grid
cell
Resolution
Columns
“Rasters are Faster...”
MAPS DIRECTLY ONTO COMPUTER
MEMORY STRUCTURE (ARRAY).
EASY TO UNDERSTAND, READ,
WRITE, DRAW
Rasters are Faster...
natural for scanned or remotely sensed data.
continuous surfaces (e.g., topography)
spatial analytical operations are faster.
compression is easier
“Rasters tell WHAT occurs everywhere.”
“ Rasters are Faster, but
Vectors are Correcter! ”
Can represent point, line,
and area features more
accurately.
Far more efficient than
grids.
Not where EVERYTHING
occurs (continuous
phenomena)…
But WHAT occurs
everywhere …
Work well with GPS
receivers.
Object/Vector Feature Types
Feature Type
Single Part
Multi-Part
Point
Line
Area
Annotation
A
Object/Vector Feature Types
1.4 GIS
Operations
SPATIAL DATA
INPUT
ATTRIBUTE DATA
MANAGEMENT
DATA DISPLAY
DATA
EXPLORATION
DATA ANALYSIS
GIS MODELS
AND MODELLING
Thank You