Introduction to Geographic Information Systems and Processes Unit I: What is GIS?

Introduction to Geographic Information Systems and Processes

Unit I:What is GIS?

Why does location matter?

• Because everything that happens, happens somewhere. (yes, even on the internet).

• Knowing where something happened is important to understanding what the effects will be.

• There are two types of location problems:1)Geographic2)Spatial

What is a Geographic Problem?

• A Geographic Problem is any problem that involves any aspect of location, either in the information used to solve them or in the solutions themselves (pg 4).

• Example:– The City of Tallahassee solves a geographic

problem when it plans garbage truck and bus routes to optimize pickups and service to the most people with the least amount of fuel or quickest trip time, respectively.

Three issues to take into account with Geographic Problems

• 1) Geographic Scale : What level of geographic detail required?• 2) Intent : What is the purpose of this analysis?

– Practical/Applied : solving a problem to achieve a specific end (minimize cost, maximize profit, etc). This is a pragmatic view.

– Human Curiosity : Mapping glacial deposits and sea level change across the world to understand Global Climate Change ( or Warming , depending on what side of the issue you are on).

• 3)Temporal (Time) Scale: When do the problems need to be solved? Over what span of time do the actions take place.– Operational (short term): where is the closest hurricane shelter for a specific

neighborhood?– Tactical (medium term): where should the county widen roads so that

evacuees can more easily and quickly vacate a flood plain next year.– Strategic (long term): Where should building codes be updated to ensure

proper storm water management to prevent future floods. (Where should new levees and storm surge walls be built to reduce the risk of inundation?)

Spatial is Special• Geographic Problems are problems dealing with

the surface (or near-surface) of Planet Earth. ( eg. The optimal bus route to serve FSU’s Campus)

• Spatial Problems are problems dealing with any (even abstract) space or spaces. (eg. the folding of proteins in reaction to a certain chemical)

• Therefore, every Geographic problem is Spatial but not all Spatial Problems are Geographic.

• We use the term Geospatial to cover both terms when discussing spatial analysis of geographic phenomena.

What is an Information System?

• Information Systems help us manage what we know, by making it easier to organize, store, access, retrieve, manipulate, synthesize, and apply knowledge to the process of solving a problem. (pg 11)

• What we know can be divided into 5 different catagories

5 divisions of What We Know

1) Data2) Information3) Evidence4) Knowledge5) Wisdom

5 divisions of What We Know

• Data: – Consist of numbers, text, or symbols which are

context free or neutral.– In a computer context they are the bits that hold

the lowest level of what we know.– Eg. Raw geographic info such as temperature at a

specific time and location.– The most important part of a GIS.– Garbage in, Garbage out.

5 divisions of What We Know

• Information:– Data that is serving a purpose.– Data that has been given some form or

interpretation.– A database is considered Information.– Independent, it exists outside of a Knower. – More ‘expensive’ to produce than data.

5 divisions of What We Know

• Evidence:– Information from different sources, related to a

specific problem, having a consistent level of validation.

– A geodatabase consisting of many layers of information covering a specific area that has been checked for accuracy in the field (ground truthing).

– Between Information and Knowledge.

5 divisions of What We Know

• Knowledge:– Information or Evidence which has value added to

it through a specific context, purpose, or experience

– Information in a book becomes Knowledge when it is read and understood by someone.

– Requires a “Knower”

5 divisions of What We Know

• Differences between Information and Knowledge:– Knowledge entails a ‘knower.’ Information exists

independently, but knowledge is related/requires people– Knowledge is harder to detach from the ‘knower’ than

information. Shipping, receiving, transferring knowledge between people are all harder than with information.

– Knowledge requires more assimilation• We may hold conflicting information, but we rarely

hold conflicting knowledge.

5 divisions of What We Know

• Wisdom:– The resulting decision made after knowing all the

information and evidence that was derived from the data, taking into account the possible consequences of the decision.

– Highly individualized almost impossible to share others completely.

– Your view of the world.

What does this have to do with GIS?

• Idiographic Geography: focuses on the description of form and unique characteristics of a place

• Nomothetic Geography: tries to describe/discover general processes.

• One important characteristic of GIS is that it allows for combination of the general with the specific.

• Knowledge with data.• The integration of Idiographic Geography with

Nomothetic Geography

What does this have to do with GIS?

• The database of a GIS represents the specific knowledge or Data/Information

• The Software of a GIS captures and implements general knowledge through analysis and computation to create more knowledge and evidence

• The Analyst makes decisions based on the analysis and contributes to the wisdom about the topic.

So What is a GIS?

• It depends…• 6 general definitions (Table 1.3)• All consist of these elements:– GIS Software– GIS Data– GIS community– Doing GIS

So What is a GIS?• GIS Software:– A piece of software one can buy from a vendor to perform

well defined functions on Geospatial data.• GIS Data:– Digital representations of the world or a space that is

usually contained in a dataset.• GIS Community:– A groups of people that use or advocate the use of these

tools for various purposes.• Doing GIS:

– The act of using a GIS (all parts) to solve a problem or advance science

6 general definitions (table 1.3)Groups of people Definition of GIS

General Public Container of maps in digital form

Planners, community leaders, and decision makers

Computerized tool for solving geographic problems

Utility and Transportation managers Digitized (mechanized) inventory of geographically distributed features and facilities

operations researchers; Management scientists (foresters)

Spatial decision support system

Resource managers, other planners Tool for performing operations on geographic data that is too tedious, expensive, or inaccurate if performed by hand

Research Scientist and Investigators Tool for revealing what is otherwise invisible in geospatial information

So What is a GIS?

• It will vary depending on your Data, Problem, and Required Application

Brief History of GIS (Table 1.4)

• Era of Innovation– 1963 - CGIS – Canadian GIS – Roger Tomlinson– 1963 - URISA – USA – Urban and Regional Information Systems and

Applications– 1964 - Harvard Laboratory for Computer Graphics and Spatial analysis– 1966 - SYMAP- First Raster GIS developed @ Harvard– 1969 - ESRI Inc Founded by Jack Dangermond (a student of the

Harvard Lab– 1972 - LANDSAT 1 Launched – First major remote sensing satellite.

Brief History of GIS (Table 1.4)

• Era of Commercialization– 1981 – ArcInfo Launched – first major commercial GIS, set new

industry standard (ESRI)– 1985 – GPS Operational – Major source of geo-locational information

and accuracy assessment.– 1988 – TIGER – US Census data in easily usable digital form –

(Topologically Integrated Geographic Encoding and Referencing) – 1994 – Open GIS Consortium – GIS Vendors, Agencies and data

providers working together to improve interoperability– 1996 – First online GIS products introduced – 1996 - Mapquest

Brief History of GIS (Table 1.4)

• Era of Exploitation– 1999 – IKONOS- New generation of Remote

Sensing satellite – 1 meter spatial resolution.– 2000 – GIS passes $7 Billion in revenue– 2004 – National Geospatial Intelligence Agency

(NGA) – Biggest GIS user in the world, US government geo-intelligence agency (National Imagery and Mapping Agency)

– 2005 – Google Maps and Earth – integrate Keyhole technology for the masses

What is GIS?

• Geographic Information Systems (GIS) are computer-based systems for the management, display, and analysis of geographic data.

• This includes the Computers, Data, and People that collect and analyze data.

Why Use GIS?

• GIS was originally developed as an extension of the use and analysis of the traditional paper map.

• The most basic form of digital map data represents the same types of data that are displayed on paper maps.

• Digital maps use the same measurement frameworks, and frequently also use the same representation methods (e.g., colors, classification schemes) used on paper maps.

Why is a GIS better than a Paper Map?

• GIS uses the analytical power of the computer to complete complex tasks which would be impossible or impractical using paper maps.

• GIS allows the integration of many different types of data from many different sources (maps, tabular data, aerial photos, elevation models, satellite imagery, CAD data, linear measurements, etc.) within an integrated storage, management, analysis, and display environment. Many of these data types are not easily represented on paper maps.

• GIS registers a variety of different data to the same coordinate space, which allows for the analysis of the combination of different layers (e.g., slope, forest windthrow hazard, distance to streams, and forest age). Frequently with paper maps, different thematic maps appear on different map sheets that are in different scales or use different representation frameworks.

• Digital data are more stable than paper media, easier to copy, and easier to distribute. Many web sites exist that distribute digital geospatial data.

Why is a GIS better than a Paper Map?

• Digitally created maps are more easily updated than paper maps (change the data and print a new copy).

• GIS allows the creation and use of "one-time" maps (whereas paper maps generally need to be printed and sold by the thousands to recapture the cost of production). For example, a map can be prepared with GIS specifically for a particular public presentation; the map may never be used after that presentation.

• GIS allows individual users to tailor their map displays for their own purposes, rather than having to settle for a general-purpose paper map.

• GIS eliminates some user bias in measurement or analytical processes (the computer repeats measurement and analytical processes identically, whereas people often repeat processes with random or systematic errors).

• GIS brings new tools for thinking differently about the world and its interrelationship.

What can GIS Do?• Locate geographic features based on their properties (e.g., "Where are all the

cities within western Washington of population greater than 5000, but less than 10,000?").

• Identify properties of geographic features based on their location (e.g., "How many people live in the cities within 20 miles of Seattle?").

• Determine a good location of a Wal-Mart, based on the demographics and land-use/availability of a given area.

• Generate optimal routing and scheduling for an appliance delivery and repair truck.

• Determine the ground area covered by a new cellular phone network. Locate "holes" in cellular coverage.

• Delineate watershed boundaries for the major tributaries of a River, and generate land-cover area statistics for those watersheds.

• Predict landslide hazard for forest harvest units, based on slope, precipitation, and soil type.

• Make colorful, interesting, and informative maps that are easily reproduced.

Anatomy of a GIS• The Network:

– Includes the Internet, WWW, and Intranets of agencies, companies, and groups– 1972 - Internet began as ARPANET (Advanced Research Projects Agency Network)– 1980 - Hypertext developed by Tim Berners-Lee

What can GIS Do?• Locate geographic features based on their properties (e.g., "Where are all the

cities within western Washington of population greater than 5000, but less than 10,000?").

• Identify properties of geographic features based on their location (e.g., "How many people live in the cities within 20 miles of Seattle?").

• Determine a good location of a Wal-Mart, based on the demographics and land-use/availability of a given area.

• Generate optimal routing and scheduling for an appliance delivery and repair truck.

• Determine the ground area covered by a new cellular phone network. Locate "holes" in cellular coverage.

• Delineate watershed boundaries for the major tributaries of a River, and generate land-cover area statistics for those watersheds.

• Predict landslide hazard for forest harvest units, based on slope, precipitation, and soil type.

• Make colorful, interesting, and informative maps that are easily reproduced.