INTRODUCTION TO GEOGRAPHICAL INFORMATION SCIENCE RSG620 Week 1, Lecture 2 March 28, 2014 Department of RS and GISc Institute of Space Technology, Karachi Week 1, Lecture 2 March 28, 2014 Department of RS and GISc Institute of Space Technology, Karachi

Introduction to GIS  What is GIS? G ?Geographical I ?Information S?System Science Studies

What is Geography? Definition: Geography is the study of the world's environment and man's interaction within the environment.” Geography has two parts: 1. PHYSICAL: The study of the earth's natural features, such as mountains, rivers, soil, vegetation, and weather 2.HUMAN: (Cultural) The study of human cultures and man made features. “All kinds of resources are used to study geography, but the most common are MAPS.”

S in GIS?  S as in System  Technology (for acquiring and managing GIS data)  S as in Science  Concept behind the technology. Theoretical foundation on which GISystems are based  S as in Studies  Societal context (social, legal, issue of privacy and confidentiality and ethical issues related to GIS application)

Why Geography is important?  Why are we more interested in spatial data today than 100 years ago? Reference: Bolastad, 2008

How an object on Earth can be defined?

…….Use …….Heights …….Species …….Type X O South, Y O West Location Information: Where is it? Attribute Information: What is it? GIS can tell us Where and What

Why GIS is Important?  What is Where? :  Query information to find location Or  Where is what?  Obtain information from a location  Impact of spatial information on our lives?  Applied geography, in the form of maps and spatial information, has served discovery, planning, cooperation, and conflict for at least the past 3,000 years (Bolstad)

GIS is about Geospatial Information  Geospatial Information: Information about places on earth  Not only Where and What but time is also important What is Where, When?

Simpler Definitions  A GIS helps us gather and use spatial data (Bolstad)  A computer system which can hold and use data describing places on the earth's surface.

... is an analysis tool... links spatial data with geographic information about a particular feature on a map... can use the stored attributes to compute new information about map features A GIS is not simply a computer system for making pretty maps. More importantly a GIS...

 A GIS is a computer-based system to aid in the collection, maintenance, storage, analysis, output, and distribution of spatial data and information.

 A powerful set of tools for collecting, storing, retrieving, transforming and displaying spatial data from the real world. (Burrough, 1986)  Any manual or computer based set of procedures used to store and manipulate geographically referenced data. (Aronoff 1989)

A decision support system involving the integration of spatially referenced data in a problem solving environment. (Cowen 1988)A decision support system involving the integration of spatially referenced data in a problem solving environment. (Cowen 1988) Systems that know how to deal with stuff in space. (Herrington 1998)Systems that know how to deal with stuff in space. (Herrington 1998)

DATABASES A Database comprises of tables having fields with specific data structure. A Database comprises of tables having fields with specific data structure. The tables are linked with each other through various common fields. The tables are linked with each other through various common fields.

MAPS Map can be defined as “A Facility for displaying interpretation of geographic information on a flat surface.” Map can be defined as “A Facility for displaying interpretation of geographic information on a flat surface.” Location information describes the position of a particular geographic feature on earth's surface & provides the basis for representing spatial relationships between these features. Location information describes the position of a particular geographic feature on earth's surface & provides the basis for representing spatial relationships between these features.

Bad Visual Interpretation BadSearching Very good Searching Very Good Visual Interpretation What? if link together

Capture Collecting data using different data structures and technologies – GPS, RS, Digitizing, etc. Store Data stored in the form of databases, spatial files, drawings, images, etc. Query A GIS must provide utilities for finding specific features based on their location or attribute values Analyze A GIS must have the ability to answer questions regarding the interaction of spatial relationships between multiple datasets Display There must be tools for visualizing the spatial information in the form of maps Output Results of display should be able to be output in a variety of formats

Data Capturing

Storing Data  Tables

Spatial Query  Query: Select Florida county Taylor on map

Spatial Analysis

Remember!!  Queries manipulate the database  Analysis transforms data into information

Display

Output

-Maps (Topographic, Statistical, 3D, Contour etc) -Atlases -Reports (Write-ups etc) -Charts, Graphs Hard Copy -Electronic map (visual digital map + multimedia) -Digital Atlas -Digital Layouts -Web Based Maps (Interactive Web Mapping) Soft Copy

GIS Key Components 1. GIS hardware 2. GIS software 3. GIS data (maps, images, database, etc.) 4. People 5. Methods Picture reference:

Hardware Hardware is the computer system on which software operates

Hardware Reference: Bolstad

GIS software combines spatial mapping and analysis with database management GIS software combines spatial mapping and analysis with database management GIS software provides the functions and tools to store, analyze, and display and disseminate spatial data and information GIS software provides the functions and tools to store, analyze, and display and disseminate spatial data and information Many public domain and commercially available software packages in the market Many public domain and commercially available software packages in the market ESRI (Environmental Systems Research Institute) line of products a good example (including ArcGIS) ESRI (Environmental Systems Research Institute) line of products a good example (including ArcGIS) Software

Key components to GIS software: 1.An easy-to-use graphical user interface (GUI) 2.Tools for entering and manipulating geographic information 3.Tools that support geographic query, analysis and visualization 4.A database management system (DBMS)

Functions Commonly Provided by GIS Software Reference: Bolstad, 2008

 Digital maps (virtual representation of world)  Map = Spatial representation of features  Database = Feature attributes Data Sources  Available through various sources like profit and non- profit organizations, academic institutions, government agencies Map + Database GIS Data

Satellite Imagery Elevation Geodetic Control Boundaries Surface Waters Transportation Land Ownership Soils Gas Pipe Lines Electric Lines Landcover Wetlands Flood Zones GIS Combines Data from Many Sources

Data Format

GIS Data

Attribute Type Nominal: descriptive information associated with a spatial entity  country name: Bangladesh, Pakistan, India, ….  highway class: Major highway, local streets, ….  crop type: Maize, cotton, wheat, ….  etc. Numeric: Real numbers usually on a linear scale (area, length, weight, height etc.) Ordinal: rank order or scale by their values. Such as small, medium, large (soil erosion class, drainage class…). Does not infer a specific scale. GIS Data

People GIS personnel may include –GIS technologist to design and maintain the system General programmers GIS developers –GIS Users GIS Managers Data providers GIS specialist/analyst General users and Public users

GIS Components  Analysis to be performed on data  To answer the question needs to be resolved  How to › Retrieve › Input into the system › Stored › Managed › Transformed › Analyzed › Presented as output Methods

Other GIS Components  Supporting institution  Protocol for use

Some Advantages of GIS  Automation of procedures involving geographic data (map making, calculation of area, slope, etc., and planning and management activities)  Integration of data from different independent domains  Visual Interpretation of spatial data depending on various criteria  Perform Spatial Queries and complex Spatial Modeling (what if scenarios)  More

Geo-spatial data are better maintained in a standard format Revision and updating are easier Easier to search, analyze and represent More value added as well as thematic product Geo-spatial data can be shared and exchanged easily Working productivity is improved and more efficient Time and money are saved Better decisions in short span of time

Class Exercise - 1  You have probably collected, analyzed, or communicated spatial data in one way or another during the past few years. Describe each of these steps for a specific application you have used or observed.

Quiz 1 1. Define GIS in your own words 2. List some things you can do with GIS 3. Describe some roles of GIS professionals 4. List the steps in defining and completing a GIS project Reference: Bolstad, Lectures

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