GEG 380: Week 1

Theoretical overview 

• Heterogenous layers & info overlay 

Data models 

• Vector model:

  • Represents real-world objects as collections of points, lines, and polygons. Vectors made of COORDINATES

  • Geometry: point, line, polygon

  • Points or dots (nodes): trees, poles, airports, cities

  • Lines(arcs): streams, streets, sewers

  • Areas(polygon); land parcels counties 

  • Produces attributes as TABLES (can be exported anywhere)

• Raster model 

  • Geography represented as cell matrixes that store numeric values that can be quantities or codes

  • Satellite images 

  • Basically a picture made of pixels (picture elements) and resolution 

  • More accurate w/ high resolution

  • Reflects light and assigns value to cells to determine land characteristics 

• WILL BE ON MIDTERM

Applications 

• Identify problems 

• Solve problems 

• Monitoring change 

GIS SOFTWARE APPLICATIONS 

Open source software (exam question)

• Free access 

• Depends on money from charities, grants, and donations 

• Low security

• Poss more complex and difficult to use than commercial software  

Commercial software (exam question)

• Company, or team can only modify content

• Pay continuous licensing fee

• Individual license granted (cheaper route) or enterprise license 

• User-friendly interface (very important)

• Comes w/ profess tech support, training materials, and customer service 

Most widely used GIS APPS

• QGIS (open source GIS)

  • More interesting to unis

• ArcGis (commercial)

  • Attractive to private agencies 

Types of GIS Software

• Desktop (most advanced & comprehensive)

  • INTERMEDIATE

  • Installed on laptop/desktop 

  • EX: ArcGIS Pro & QGIS

  • Full control for creating, managing, editing, visualizing, and performing advanced analyses of geo data

• Web

  • BEGINNER

  • Web based application 

  • EX; ArcGIS, Carto, Mapbox

  • Able to view maps, upload additional data, customize the display, and perform basic analyses

  • Good for statistical based maps 

  • Good for colorful maps

  • Need to use login 

• Geobrowser/Cloud GIS 

  • ADVANCED

  • On the web browser interface. Uses cloud to run tasks 

  • EX: google earth engine 

  • View satellite images, run spatial analysis on the cloud, and perform advanced programming tasks 

  • Can use data for global based research/analysis (very advanced)

Mobile GIS 

• Google maps 

• Gps function produces ore accurate and overall improvement in data quality 

• For orgs concerned about land management 

• Localized & real-time data 

• Fieldwork → office → server for users