Data Management Brown Bag: Geographic Information

Systems (GIS) Data

A.K.A Spatial Data

Joe Aufmuth

GIS Librarian

mapper@uflib.ufl.edu

273-0367

Today’s Focus• An overview of GIS: definition, principals,

data types, and ArcGIS• Spatial Data Source Limitations• Is GIS the Correct Research Tool?• Spatial Data Sources• Summary of Spatial Data Users @ UF

Soil Information System of Thailandhttp://www.mcc.cmu.ac.th/research/DSSARM/SoilSys/soilsys.html

GIS Models The Real World

GIS: A Definition

A Geographic Information System, or GIS is composed of computer hardware, software, geographically referenced digital data (spatial data), and people (data accuracy and bias).

A GIS is used to collect, store, update, manipulate, analyze, and display all forms of geographic information.

A GIS models or represents geographic features and can measure or predict their interactions.

Multiple Data Layers

Where it is (position)

What it is (description)

When it was there (time)

Quantity, Proximity Spatial Analysis How Features interact

“What if..” Predictions

ESRI

Principal GIS Concepts

• A data model (geo-database) that uses location and description to mimic the “real” world. (also temporal)

• Spatial information (X,Y,Z elevation) about three vector feature classes (POINTS, LINES, POLYGONS) and a linked tabular database of their multiple attributes or descriptions (grid cells have a singular attribute).

• ***Common reference system for all layers used in the GIS. PROJECTION, DATUM (horizontal and vertical), SPHEROID and UNITS (Lat/Long = spherical coordinate system, not suitable for analysis)

• Facilitates overlay of multiple layers to create and analyze new temporal and spatial relationships between features

Two Spatial Data Formats

Vector Raster Points, Lines, and Polygons Grid Cells (Pixels)

Visualize the WorldThree Vector Feature Classes:

Points, Lines, and Polygons• Point: A discrete or single location with no

discernible area at a specified scale.

• Line/Arc: A set of ordered coordinates (x,y) that when connected represent the linear shape of a narrow object.

• Polygon (area): A closed figure composed of lines that enclose a homogeneous area.

Vector Data

Polygon

To Node

Vertex

Line (Arc)

From Node

Point

No Area

No AreaAreaHomogeneous

Left

Right

Tabular Data

Columns = Fields = Items = Attribute = Description

Rows = Records= Features

Data (text, number, date)

Grid/Raster/Imagery Data(Greater Data Variability based on Cell Size)

# Rows

# Columns Numeric Cell Value1 value per cell

Exampleselevation, land use, flow rate, drainage direction, temperature, salinity, reflectance, etc…

Gradients and VariableData

ArcGIS Software: ArcMap Program

ArcMap uses vector data in a special format called a “SHAPEFILE”.

A single shapefile layer contains either points, or lines, or polygons.

A shapefile is composed of several individual files that include vector data, a relational database, coordinate projection, data index, etc.

ArcGIS is no longer paid for by the Provost

A Shapefile and It’s Attribute Table:

A Map of Countries:- One polygon file - Each country is one

feature- Data display is not a

map

GPS Table – GIS Import

Typical Data Layers• Administrative and

Political Boundaries • Cities• Historic Sites Inventory• Land Cover and Use• Imagery (Satellite and

Aerials)• Soils• Hydrology• Census

• Roads• Railroads• Elevation• Fire Hydrants• Township, Range and

Section• Species Distributions• Property Boundaries• All in a Common

Coordinate System

Source Data Limitations• Different Purposes, Sources, and Reliability of Digital

Spatial Data (digital = accurate)– Federal, State, Local, Private– QA/QC of All Data (positional and attribute accuracy)

• Different Coordinate Systems (Geographic vs Projected)– Latitude/Longitude – Global/Spherical Reference System– Projection – Plane/Surface Grid Coordinate System– Every Layer Must Share a Common Projected Coordinate System

for Analysis

• Different Digital Data Collection Scales and Uses– Small Scale / Large Area – Regional Analysis (1:100,000)– Large Scale / Small Area – Local Analysis (1:24,000)

Source Data Limitations• Representing a particular real world location with a point,

line, or polygon is scale dependent.

• At small scales (1:500,000) areas become a single line or point (generalized features/low resolution).

• At large scales (1:2000) lines and points may have area (detailed/higher resolution).

• Usable data scale = Data source scale or smaller.– GPS data = 1:1

vs

The Appropriate Research Tool?• Is the research question a spatial problem? • What research data is needed and how can GIS be

used to obtain it? Are spatial operations involved? (clip, buffer, union, intersect, identity, etc..)

• What level of spatial resolution/scale and positional accuracy is required?

• Does needed spatial data exist or does it have to be created? Is descriptive tabular data available?

• Can detailed descriptive tabular data be joined to spatial data at the current data resolution/scale?

• Is it easier to make a graphic or map in another program? I need a pretty map!

Spatial Data Sources

• GOOGLE Search Terms• GIS Data Clearinghouse = 338,000 • GIS Data Sources = 4,400,000• GIS Data Download = 19,100,000• GIS Database = 27,900,000

Spatial Data in The CloudFlorida Geographic Data Library (FGDL), Florida’s Statewide DataUF’s URP GeoPlan Center www.fgdl.org

LABINSFlorida’s Land Boundary InformationSystemwww.labins.org

U.S. Geo Spatial One StopThe US’s GIS data portalwww.GeoData.gov

AfricoverFood and AgricultureOrganization of the UNwww.africover.org/system/africover_data.php

Subscribed Spatial Databases

LandScan 2010 Global Population

World Language Mapping System

SimplyMap demographic data

UFDC Digital Collections

The Map and Imagery LibraryOver 500,000 Maps plus atlases, reference books, aerial photography, and spatial data.

Specialized tours and class instruction by appointment.

Area specialties include: Florida, Latin America, the United States, Africa, and the Holy Land.

Scanners and computers with GIS and remote sensing software are available

More information can be found at http://www.uflib.ufl.edu/maps/

GIS and Remote Sensing Users @ UF

=++ Zonal Attributes

GIS Cataloged References @ UFGIS use only limited by the imagination!

Geographic Information Systems AND…• Public Health – 71• Forestry – 56• Business – 189• Conservation – 375• Policy – 371• Dissertation – 190• Thesis – 232 1988

1997

UF ArcGIS User Summarywww.geoplan.ufl.edu

• ~ 700 Students Annually, Free Education Edition

• 40+ units on campus that use the concurrent use license for ArcGIS Desktop (from 1 to unlimited licenses)

• Agricultural and Biological Engineering

• Agricultural Education and Communication

• Biology• Bureau of Economic and Business

Research (BEBR)• Civil and Coastal Engineering• College of Agricultural and Life

Sciences - CALS (includes Soils)• College of Design, Construction &

Planning• College of Vet Medicine -

Administration• Coop. Extension, County Ops.• Department of Epidemiology• Department of Health Outcomes

and Policy - Community Denistry

• Department of Urology• e-Learning Support Services /

Office of Academic Technology• Emerging Pathogens Institute• Environmental Horticulture• Fire Science• Florida Museum of Natural History• Food and Resource Economics

Department• Forest Resources and Conservation

- SFRC (includes Fisheries)• Geography• GeoPlan• Horticulture• IFAS - Citrus Research and

Education Center (CREC)• IFAS - Entomology and

Nematology

• IFAS - Everglades Research and Education Center (EREC)

• IFAS - Florida Medical Entomology Lab (Vero Beach)

• IFAS - Fort Lauderdale Research and Education Center (FLREC)

• IFAS - Indian River Research and Education Center (IRREC)

• IFAS - North Florida Research and Education Center (NFREC)

• IFAS - Osceola County• IFAS - Plant Science Unit• IFAS - Southwest Florida Research

and Education Center (SWFREC)• IFAS - Statistics• IFAS - Tropical Research and

Education Center (TREC)• IFAS - West Florida Research and

Education Center (WFREC)• IFAS Center for Aquatic &

Invasive Plants

• Institute for Child Health Policy• Libraries (Unlimited Licenses)• LUCIE (includes Geogrphay)• Maternal Child Health and

Education Research and Data Center, Dept of Pediatrics (Now called FDC)

• Office of Institutional Planning & Research

• Program for Resource Efficient Communities

• Sea Grant• UF Planning• UF Shands Cancer Center• University of Florida Foundation

Research Department• Wildlife Ecology and Conservation

Image Analysis SoftwareImagine/ENVI User Departments• CISE• Ag and Bio Engineering• Geomatics -- School

Forest Resources• Libraries (5/5)• CREC, Lake Alfred

Experiment Station• Ft. Lauderdale Fish and

Wildlife• Geography/LUECI Lab• Soil and Water Sciences

• Ag and Bio Engineering• Wildlife, Ecology and

Conservation• GeoPlan Center• Florida Cooperative Fish

and Wildlife Research Unit

• Fisheries and Aquatic Sciences

UF’s Graduate LevelInterdisciplinary Concentration

in GIS (ICGIS) Degrees

Note: (N) - non-thesis degree; (O) - thesis with non-thesis option degree; (T) - thesis degree

http://www.uflib.ufl.edu/icgis/

ICGIS

10 Participating Degree Programs in:Agricultural and Biological Engineering

Environmental Engineering SciencesLandscape Architecture

Geomatics Program Forestry

GeographyAnthropology

Soil and Water ScienceUrban and Regional Planning

Wildlife Ecology and ConservationSchool of Natural Resources and Environment

15 Total Credit Hours; 5 Categories of Courses; 29 Classes; 20 Professors

• http://www.uflib.ufl.edu/gisday/gisday2012/agenda2012.html

Converting Maps To Digital Data

Geo-referencing: assigning “real world” coordinates to a

digital object

Modern/Ancient Jerusalem 1887Paper to Digital (Remlap, L. T)

Large Format Digital Image Capture

Desktop Image Capture

Google Maps: Jerusalem

ArcGIS: Jerusalem Imagery

Geo-referencing – image coordinates to “real world” coordinates

Finding Common Image and Real World Control Points

Georeferenced Digital MapNew Historic Data Layers

QUESTIONS?