QBB 4113
Geographical Information System
and Geomatics
Objectives
• Utilise GIS as a spatial analysis tool, decision
support system and intelligent mapping tool for
geosciences applications.
Learning Outcomes
• Apply GIS database as a mapping tool
• Conduct a GIS based geohazard mapping
Assessment Methods:
Coursework – 50%
Final Exam – 50%
Main References:
1. Bonham-Carter, G.F. 1994. Geographic Information
Systems for Geoscientists: Modelling with GIS.
Ontario: Pergamon
2. Burrough, P.A. 1991. Principles of Geographical
Information Systems for Land Resources Assessment.
Oxford: Calendron Press
Fundamentals of GIS
Fundamentals of GIS
Objectives
• To understand the basic concept of GIS including
functions, systems and usefulness of GIS
• To identify needs of GIS for the management of
natural resources and environment
• To understand the process of decision making
using GIS
Fundamentals of GIS
Contents
1. Definition of GIS
2. Why is a GIS needed?
3. Required functions for GIS
4. Computer systems for GIS
5. GIS as a multi-disciplinary science
6. Areas of GIS applications
7. GIS for decision support
Definition of GIS
• Geographic Information System or GIS is
defined as an information system to input,
retrieve, process, analyze and visualize
geographically referenced data or
geospatial data in order to support
decision making for planning and
management of natural resources and
environment
Why is a GIS needed?
• Geospatial data are poorly maintained
• Maps and statistics are out of date
• Data and information are inaccurate
• Geographic data are inconsistent
• There is no standard
• There is no data sharing
• There is no data retrieval service
• There is no scientific decision making
What is GIS?
There are a number of definitions of GIS. Different groups of people (general public,
planners, teachers, scientists) can find a different definition useful.
Here are some of them:
“GIS is much more than a container of maps in digital form”.
“A GIS is a computerized tool for solving geographic problems”
“GIS is a spatial decision support system”
“GIS is a mechanized inventory of geographically distributed features and facilities”
“GIS is a method for revealing patterns and processes in geographic information”
“GIS is a tool to automate time-consuming tasks that are too tedious or expensive or
inaccurate if performed by hand”
“GIS is a collection of computer hardware, software, and geographic data for
capturing, managing, analyzing, and displaying all forms of geographically referenced
information.”
Key Components of GIS
Concept of Geospatial Data
Benefits of GIS
• Geospatial data better maintained in a
standard format
• Revision and updating easier
• Search, analysis and representation easier
• More value added products
• Data can be shared and exchanged
• Productivity more improved
• Time and cost saved
• Better decision making
Basic Functions of GIS
Basic Functions of GIS
Functions Sub-functions
Data Acquisition and Preprocessing Editing, Topology Building, Format
Conversion etc.
Database Management and Data archiving, Query etc.
Retrieval
Spatial Measurement and Analysis Buffering, Overlay Operations etc.
Graphic Output and Visualization Mapping, Bird’s Eye View etc.
Computer Systems for GIS
Hardware System
GIS Software
• Arc GIS
• GeoMedia
• MapInfo
• IDRISI
• ILWIS
• GRASS
• QGIS
GIS as a Multidisciplinary Science
• Geography • Computer Science
• Cartography • Mathematics
• Remote Sensing • Statistics
• Photogrammetry • Operations
• Surveying Research
• Geodesy • Civil Engineering
• Urban Planning
Areas of GIS Applications
What is an ideal GIS?
Applications of GIS in Oil and Gas
Applications of GIS in Water Resources
Management
Applications of GIS
in Landslide Hazard
Data Models and
Structure
Data Models and Structure
Objectives
• To understand the concept of data model and
structure, especially vector model and raster
model
• To understand the topological data structure and
relationship
• To develop thematic data modeling
Vector and Raster Model
Two major types of geometric data model:
• Vector Model
Vector model uses discrete points, lines and/or
areas corresponding to discrete objects with
name or code number of attributes
• Raster Model
Raster model uses regularly spaced grid cells in
specific sequence
Vector and Raster Model
Vector and Raster Model
Advantages of Vector Model
Precise Expression
Less Data Volume, Full Topology
Fast Retrieval
Fast Conversion
Disadvantages of Vector Model
Complicated Structure
Difficulty in Overlay
Difficulty in Updating
Expensive Data Capture
Vector and Raster Model
Advantages of Raster Model
Simple Data Structure
Easy for Overlay and Modeling
Suitable for 3D Display
Integration of Image Data
Automated Data Capture
Disadvantages of Raster Model
Large Data Volume
Difficulty in Network Analysis
Slow Conversion
Geometry and Topology of Vector
Data
• Spatial Objects are geometrically represented by
Point, Line and Area
• For spatial Analysis in GIS, only the geometry with
the position, shape and size in a coordinate
system is not enough but the topology is also
required
• Topology refers to the relationships or
connectivity between spatial objects
Geometry and Topology of Vector Data
Topological relations between spatial objects
Topological relations between spatial objects
Geometry and topology of point objects with
raster data
Geometry and topology of line objects with raster
data
Geometry and topology of area objects with raster
data
Flow Directions
Map Layers
Thank you
