GIS Basics

1. GIS
Introduction & Basics of Geoinformatics

4. Geography - Pattern and process of human and physical phenomena on
the surface of earth.
• What is where? (Spatial Distribution and Variations)
• Why is there? (Spatial Interactions)
• Why do we care? (Spatial Planning and Management)
Geographic

7. Information is processed data useful for problem solving.
• Data is basically the collection of facts and figures that pertain to places,
people, things, events, and concepts.
Spatial Data/ location
Also known as geospatial data or geographic information, it is the data or
information that identifies the geographic location of features and
boundaries on Earth, such as natural or constructed features, oceans, and
more
Information

15. A Geographic Information System (GIS) is a system that integrates
hardware, software, and data for capturing, managing, analyzing, and
displaying all forms of geographically referenced information
GIS - Definitions
Four main Functions
• Data capture (e.g. data entry, scanning, digitizing,)
• Data manipulation (e.g. editing, data conversion, data integration, etc.)
• Data analysis
• Data presentation and output (e.g. map making, printing, etc.)

16. Geo-Spatial Data
Two components of geospatial data: geographic position and attributes/
properties
• Geographic position answers “where is it” - referred as spatial data
 the location of a geographic feature or phenomenon (x, y, z)
• Attributes answers “what is it?” – attribute/non spatial data
• GIS stores geospatial data, with its attribute information in a GIS
database
• Provides link between the geographic position/spatial data and attribute
data/non-spatial data

19. Data Elements
 Points:
• Have no length or area at the given scale
• Usually have a single X, Y coordinate
• Represent a feature that is too small to be displayed as a line or area
 Arcs / Lines:
• Have length but no width
•Are accompanied by a set of coordinates
•Represent a geographical feature that is too narrow to have area, such
as a creek or road
 Polygons / Areas:
• Have an area that is given by the arcs/lines that make the boundary.
• Are used to represent features that have area (e.g. lakes, large cities
and islands)

20. Data Elements

22. • Polygone
• Lines
• Points
• Images
(pixels)

23. FUNCTIONS OF GIS
 Input
 Manipulation
 Management
 Query and Analysis
 Visualization

24. FUNCTIONS OF GIS
Data Input
• Converts existing data into GIS format
• Common sources of data include paper maps, tables of attributes, aerial
photos, and satellite imageries
• A major bottleneck in the implementation of GIS

25. FUNCTIONS OF GIS
Data Manipulation and Analysis
• Allows the user to define and execute spatial and attribute procedures to
generate derived information
• This subsystem is commonly thought of as the heart of a GIS, and
usually distinguishes it from other database information systems and
computer-aided drafting (CAD) systems.

26. FUNCTIONS OF GIS
Data Management and Storage
• Organizes the data, spatial and attribute, in a form which permits it to be
quickly retrieved by the user for analysis
• Permits rapid and accurate updates to be made to the database
• Involves use of a database management system (DBMS) for maintaining
attribute data

27. FUNCTIONS OF GIS
Query and analysis
• GIS provides both simple point-and-click query capabilities and
sophisticated analysis tools to provide timely information to managers
and analysts alike.
• GIS technology really comes into its own when used to analyze
geographic data to look for patterns and trends and to undertake "what if"
scenarios.
• Modern GISs have many powerful analytical tools

28. FUNCTIONS OF GIS
Visualization
• Presentation of outputs by maps and visualization tools (e.g. 3-D,
animation)
• Allows the user to generate graphic displays, normally maps, and tabular
reports representing derived information products.

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