Introduction to Geographical Information Science RSG620 Week 1, Lecture 2 Feb 17, 2016 Department of RS and GISc Institute of Space Technology, Karachi Introduction to Geographical Information Science RSG620

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

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

Location Information: Where is it? Attribute Information: What is it? There are two ways of explaining any element/object on the Earth ……. Location Information: Where is it? Attribute Information: What is it? GIS can tell us Where and What Geospatial data tells you where it is and attribute data tells you what it is. Metadata describes both geospatial and attribute data

Why GIS is Important? What is Where? : Where is what? Or 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 mankind in many applied fields like navigation, discovery, planning, etc. for at least the past 3,000 years What is Where? At which pole polar bear lives? Where you may find rain forest? Where is what? At North Pole what dominant land animal is found? At tropical region what type of forests are found?

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.

GIS... A GIS is not simply a computer system for making pretty maps. More importantly a GIS... ... 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 Source of this slide: Tim Haithcoat

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

Some other popular definitions of GIS 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)

Some other popular definitions of GIS 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)

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

Conventional Ways to Store Data MAPS 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. Map

Visual Interpretation Visual Interpretation Databases Vs Maps Very good Searching Bad Searching What? if link together Bad Visual Interpretation Very Good Visual Interpretation

Basic GIS Functions

Basic GIS Functions 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

GIS Functions Data Capturing

GIS Functions Tables Storing Data

GIS Functions Spatial Query Query: Select Florida county Taylor on map spatial queries (how many utility stores within 10 minutes from major highways?, How many emergency services located within a community?) Query: Florida counties with a population greater than 300,000

GIS Functions Spatial Analysis Create a new area within a user-defined distance of an existing entity.

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

GIS Functions Display

GIS Functions Output

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

GIS Key Components GIS hardware GIS software GIS data (maps, images, database, etc.) People Methods GIS require trained people to use them. Picture reference: http://www.mapsofindia.com/images/gis-components.jpg

GIS Components Hardware Hardware is the computer system on which software operates

GIS Components Hardware Reference: Bolstad

GIS Components Software Many public domain and commercially available software packages in the market ESRI (Environmental Systems Research Institute) line of products a good example (including ArcGIS)

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

GIS Components Map + Database GIS Data Map + Database 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

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

GIS Components GIS personnel may include 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 Methods 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

Other GIS Components Supporting institution Protocol for use Although new users often focus on GIS hardware and software components, we must recognize that GIS exists in an institutional context. Effective use of GIS requires an organization to support various GIS activities. Most GIS also require trained people to use them, and a set of protocols guiding how the GIS will be used. The institutional context determines what spatial data are important, how these data will be collected and used, and ensures that the results of GIS analyses are properly interpreted and applied. GIS share a common characteristic of many powerful technologies. If not properly used, the technology may lead to a significant waste of resources, and may do more harm than good. The proper institutional resources are required for GIS to provide all its potential benefits.

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

GIS Benefits 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 Time and money are saved Better decisions in short span of time

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