What is GIS? Introduction to gis and arc gis

2. INTRODUCTION TO
GEOGRAPHIC INFORMATION SYSTEMS (GIS)

3. What is GIS?
 A GIS integrate hardware, software and data for capturing,
managing, analysing and displaying all forms of geographically
referenced information.
 A 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.

4. Geographic Information System
 Geographic – 80% of government data collected is associated with
some location in space
 Information - attributes, or the
characteristics (data), can be used to symbolize and provide further
insight into a given location
 System – a seamless operation linking the information to the
geography – which requires hardware, networks, software, data, and
operational procedures
…not just software!
…not just for making maps!

5.  Homes
 School Districts
 Streets
 Zip Codes
 Cities
 Counties
CAPTURE
STORE
QUERY
ANALYZE
DISPLAY
OUTPUT
GIS FUNCTIONS

6.  Capturing Data: A GIS must provide methods for inputting
geographic (coordinate) or tabular (attribute) data. The more input
methods available, the more versatile the GIS.
 Storing Data: There are two basic data models for geographic data
storage: vector and raster. A GIS should be able to store geographic
data in both models.
 Querying data: A GIS must provide utilities for finding specific
features based on location or attribute value.
 Analyzing data: A GIS must be able to answer questions regarding
the interaction of spatial relationships between multiple data sets.
 Displaying Data: A GIS must have tools for visualizing geographic
features using a variety of symbology.
 Output: A GIS must be able to display results in a variety of formats,
such as maps, reports, and graphs.

7. COMPONENTS OF GIS

8.  People: This is the most important component in a GIS. People must
develop the procedures and define the tasks of the GIS. People can
often overcome shortcomings in other components of the GIS, but
the best software and computers in the world cannot compensate for
the incompetence of people.
 Data: The availability and accuracy of data can affect the results of
any query or analysis.
 Hardware: hardware capabilities affect processing speed, ease of
use, and the type of output.
 Software: This includes not only actual GIS software, but also
various database, drawing, statistical, imaging, or other software.
 Procedures or Methods: Analysis requires well-defined, consistent
methods to produce accurate, reproducible results.

9. HOW GIS WORKS
Thematic
object
selection
Real world
Maps
-Analysis
GIS operations
Cartographic
processing
.- Generalization
- Symbolization
Geology
Hydrology
Soil
Attribute tables
Decision makers
Statistical tables
GPS Satellite imagesAerial photographs
Point
Area
Line
Field Survey

10. GIS WORKFLOW

11. DATA IN GIS
Spatial and Attribute data
There are two important components of
geographic database: its geographic position
and its attributes or properties. In other
words, spatial data (where is it?) and
attribute data (what is it?)

12. SPATIAL DATA
City blocks Land use
001 Institutional
002 Commercial
003 Commercial
004 Residential
005 Residential
006 Residential
007 Industrial
008 Residential
009 Industrial
010 Industrial
011 Residential
012 Industrial
013 Residential
014 Residential
015 Residential
Map: City blocks
ATTRIBUTE DATA
SPATIALAND ATTRIBUTE DATA

13. What makes data spatial?
PlacenameGrid co-ordinate
Postcode
Distance & bearing
Description
Latitude / Longitude

14. Characteristics of spatial data
 Location
 Description: University of Azad Jammu and Kashmir
 Post Code: 13100
 Latitude/Longitude: 33° 21’ 55.38”N, 73° 36’ 17.62”E

15. Characteristics of spatial data
Geometry
 The shape of a
building or county
 The course of a
river, the route of a
road
 The shape of the
landscape, relief

16. Maps model the real world with points, lines, and polygons. Symbols and labels
describe the descriptive information about the geographic features.
Points
Points define the discrete locations of geographic features which are too small to
illustrate as lines or polygons such as well or telephone poles. Points can be used
to illustrate the locations of mountain peak or discrete elevation points.
Lines
Lines represent the linear features of geographic object too narrow to illustrate as
polygons, such as streets and streams that have length but no area. Moreover,
contour lines are represented as the lines
By using different symbols and labels, descriptive information of linear features are
illustrated. For example: Roads are drawn with various line widths and patterns and
colors to represent different road types, e.g., highway as wide solid red colour line,
blue lines are used to illustrate the streams. The symbol can be used to
illustrate the railway.
City streets are labeled with names and often address ranges.
BASIC TYPES OF SPATIAL DATA

17. Polygons
Polygons are closed features that represent the shape and location of
homogeneous features such as landuse, forest types. Tone of the colour
can be applied to illustrate the density of population, green color can be
used to represent vegetation and blue colour can be used to illustrate
lake.
Surfaces
A surface represents the elevation, presence or absence of something for
every point on the piece of earth. The elevation models are best examples
to illustrate as the surfaces.
Surfaces are typically represented on the maps as the series of isolines.
Elevation contours, rainfall, temperature can be represented as the
surface of isolines.
Surfaces can be represented as the Raster Elevation Model and Vector
Elevation Model.

18. Point Line
Area
surface
GEOMETRY OF SPATIAL DATA

19. Vector Graphics:
•Images are built-up from points, lines (segments) and areas
(Polygons).
•Each defined by pair of X-Y co-ordinates.
•Preparing a map by digitization is converted into vector data in
computer.
Raster Graphics:
•Images are built-up from cells which is called as Pixels.
•In raster graphics, the smaller the area of land that each cell
represents, the higher the resolution of the data and higher the
spatial accuracy, ultimately the larger the files needed to store
the data.
.For continuous data such as elevation, slope, surfaces.
REPRESENTATION OF GEOGRAPHIC DATA

20. VECTOR AND RASTER REPRESENTATION

21. Raster
Vector
Real World
VECTOR AND RASTER REPRESENTATION

22. GIS LAYER
 A GIS stores information
about the world as a
collection of layers that can
be linked together by
geography.
Real World

23. Why do we need GIS?
 Because location is important, It is an issue in many
of the problems society must solve. Problems that
involve an aspect of location, either in the
information used to solve them, or in the solutions
themselves, are termed geographic problems.

24. Examples of geographic problems
 Health care managers solve geographic problems “Where to locate new clinics
and hospitals”
 Delivery companies solve geographic problems when they decide the routes,
and schedules of their vehicles, often on a daily basis.
 Transportation authorities solve geographic problems “When they select routes
for new highways”
 Forestry companies: They determine how best to manage forests, etc.
 Governments solve geographic problems when they decide how to allocate
funds for building sea defenses

25. APPLICATIONS OF GIS
 Applications generally fulfill the five M’s of GIS:
 mapping,
 measurement,
 monitoring,
 modeling,
 and management

26. APPLICATIONS OF GIS
 land-use planning and management
 oil & mineral exploration
 environmental impact studies
 management of water resources
 natural hazard mapping
 forestry and wildlife management
 soil degradation studies
 agricultural development
 socio-economic survey and mapping
 Measurements of landscapes or structures
 Transport/vehicle routing
and many more . . .

27. INTRODUCTION TO ArcGIS SOFTWARE

28. ArcGIS is a Product of
ESRI
ENVIRONMENTAL SYSTEM RESEARCH INSTITUTE

29. It is available in three license level……….
 Basic, ArcView
 Standard, ArcEditor
 Advanced, ArcInfo
ArcGIS Desktop Software

30. Exploring ArcGIS Desktop
ArcView: viewing, map production, spatial analysis,
basic editing
ArcEditor: ArcView, plus specialized editing
ArcInfo: ArcView & ArcEditor plus special analysis
and conversions
• All three software products look and work the same. They differ
only in how much they can do.
• ArcEditor does more than ArcView, and ArcInfo does more than
ArcEditor.

31. ArcInfo is now referred to as ArcGIS for Desktop Advanced
ArcInfo

32. Mapping & Analysis for Understanding Our World
ArcGIS Desktop
Version 10.1

33.  ArcMap
Mapping, editing, analysis
 ArcCatalog
Manage spatial data, database designs, creation and management of metadata
 ArcToolbox
GIS data conversion and geoprocessing
 ArcScene
3-D display
Main components of ArcGIS

34. Powerful map creation and spatial data editing.
ArcMap is the main interface for conducting
analysis and creating maps. Here, feature
classes and shapefiles can be populated, data
can be edited, calculations can be performed,
and finally, maps can be created for displaying
the results of the GIS analysis
ArcMap

35. Open Arc Map

37. Tool Bar
DISPLAY WINDOW

38. ArcCatalog

39. Arc Tool Box