Geographic Information

Systems

Michael Kennedy

Department of Geography

University of Kentucky

kennedy@uky.edu

Tue 23 Feb 2010

Cyberinfrastructure Days

GIS in General

Spatial data

GIS at UK

The Process: PAST

Data Collectors

Cartographers

Photographers

Geographers

Printers

Trail Specialists

For plannersand decision-makers whotake some action to affect.

f

“Mapping” Map

EXAMPLES OF THINGS MAPPED:“Themes” or “Layers”

• Land Elevation

• Land Slope

• Soil Type

• Land Use, Land Cover, Zoning

• Population Data

• Dental Cavities of Children

• Wildlife Habitat

• Sites of Auto Accidents

• Roads and Railroad Lines

• Energy Use Patterns

ADVANTAGES OF A DIGITAL GEOGRAPHIC INFORMATION

SYSTEM

• Size of Memory• Updatable• Recurring Data Sources• Overlays Possible• Analysis “easy”

• Maps are Intuitive• Maps are Portable• Maps are Honest

But:

THREE FORCES FOR CHANGE

(1) Difficulties with Maps

• Hard to Analyze• Hard to Compare Among• Compromise between

two functions:--Storage--Display

(2) BEFORE 1960’S

Resources,energy,land,etc.

Waste,heat,etc.

HumanActivity

AFTER 1960’S

HumanActivity

Resources,energy,land,etc.

Waste,heat,etc

(3) GARDEN-VARIETY COMPUTER POWER

1960 Lately

Memory Size 1 10000(Primary) (60Kb) (600Mb)

Memory Size 0 (On-line, (zilch) (500 Gb) Secondary)

CPU Speed 1 10000 (200u sec) (20nsec)

Cost 1 1000 $500,000 $500

SIMPLISTIC FORMULA FOR CALCULATING

BANG FOR THE COMPUTING BUCK

P = M * S / $

Factor increase since 1960:

1013

GEOGRAPHIC INFORMATION SYSTEM

Need for BetterResource Allocation

MapShortcomings

(2)(1)

Computers(Stupid,

fast,accurate)

People(smart,slow,

sloppy)

$$$(3)

(5)

(4)

The Process: NOW

STORAGE

DigitalComputer

Store

Data CollectorsCartographersPhotographersGeographersPrintersField SpecialistsComputer ProgrammersComputer Scientists

f1

queries f2

DISPLAY

For planners, etc.

Geographic Information System:

A Tool to Aid in

Managing the

Environment

-------------------------

The marriage of a

(geo)graphic database and

an attribute database

Building a

Geographic Information System

(How to make a computer believe its a map)

•Data Acquisition & Input

•Data Structure & Storage

•Analyzing & Processing

•Information Display

Spatial Data

•Data (symbols, graphics, numbers)

•Physical Medium

•Position Locator

Exclude: change, move, <1 centimeter

Classes of Spatial Data

•Maps

•Photographic Materials

* Digital files which contain spatial locators

Spatial Data Bases

Inherent Difficulties:

• Size & Number of Data Sets• Diverse Acquisition• t• Locational Reference

(point, line, area, volume, time)• Continuous vs. Discrete

(x,y) (z) (no 1 for 1)• No Natural Development• Coordinate Systems• “Not-Basic-Data” Attitude• Always Errors

Basic Problem

Extract significance from

continuous, virtually infinite,

4-D environment;

place in 1-D discrete store;

and

return relevant information

in 2-D formats (maps, tables)

Answer:•Idealize•Aggregate•“Probabilize” (interpolate, extrapolate)

•Categorize

A Storage Paradigm

Storage Paradigms

Vectors

•Cell (grid, raster)•Polygon•TIN

For Point Data“Just” Coordinates

For Lineal Data

For Areal Data

CELL:

+ Overlay Capability

- Artificial, Arbitrary- Poor Geographic Specificity- Resolution Compromise

POLYGON:

+ Appropriate Boundaries+ Best Geographic Specificity

- Processing Time for Overlays+ - Storage Requirements- Locked to Data Base Size

A BC

1

2

3

TIN:

+ Can use significant points+ Continuous 3-D Surface+ Gives elevation, slope, aspect- Surface non-differentiable- Uses plane facets

Geographic Information System

Products

Criteria for Use by Decisionmakers:

Availability Known•Understandable•Worth Time Investment•Assistance Available•Timely•Relevant•INTEGRITY

•Purpose• Inventorying•Analyzing•Explaining•Documenting•Defending•Forecasting•Monitoring•Planning

HAVE:

•Remote Sensing (satellite)•Remote Sensing (aircraft)•Natural Science, Demographic

Data•Computing Power

Great Speed

Immense Storage•Expertise for specific-purpose

systems

DON’T HAVE:

• Models to simulatecomplex environments

• Common set of storage paradigms or formats

DON’THAVE:

• Governmental Understanding of :

vs.

Smart Fast

People Yes

Computers Yes

Large Governments

• Governmental Commitment

Some images of local spatial data sets

Kentucky RiverWater Filtration PlantTopographic QuadrangleElevation: Contours, DEM, TINNetworks: Highways and RoadsSoil TypesMajor StreamsGPS TrackGraphic OverlayUK Campus: Orthophoto Issues Resolution Issues Time & Change (1994,2002)

What has all this to do with

Cyberinfrastructure?

One theme: Six inch orthophotography requires 16 bytes of storage per square foot – 0.5 GB

per square mile.

Fayette County needs 118 GBKentucky needs 16.4 TB

CyberinfrastructureCan it provide:

A Geographic Information System

--with--•Spatial Data Library (plug in data AND metadata) (made up of basic data)

•Analysis Capability (including “map standard” information output with statements of accuracy and precision)

Geographic Information Systems

at the University of Kentucky

KGS spatial data on the web

Remote sensing on agricultural crops

Optical detecting of nitrogen deficiency

Land use assessment in Google Maps

Kentucky Land Education and Research (KLEAR)

3D visualization of urban landscapes

Textbooks

UK Organizations involved with the GST Working Group

AnthropologyBiosystems and Agricultural EngineeringCenter for Visualization and Virtual EnvironmentsEarth and Environmental SciencesForestryGeographyKentucky Geological Survey (KGS)Landscape ArchitectureLinguisticsPhysical PlantPolitical SciencePublic HealthStatistics

Hopes for Geospatial Technology at UK

HAVE:

•Really Good People•Interesting Projects•Lots of Enthusiasm•Plenty of Computing Facilities•Site License for Vital Software

DON’THAVE:

• Any Formal UK Recognition• $$$• Other Important Software• Instruction beyond Intermediate• Undergraduate Certificate• Graduate Certificate• Minor• Major• Coordinator (teaching, research, outreach)

See the UK GST Poster at the CI Days Forum

Thank you !