W01 - Introduction

Question 1

geographic information system (GIS)

Answer 1

computer system for capturing, storing, querying, analyzing, and displaying geospatial data

Question 2

geospatial data

Answer 2

describes both the locations and characteristics of spatial features

Question 3

what does a GIS require besides geospatial data?

Answer 3

hardware (ex. computers, operating systems, monitors, scanners, GPS receivers, etc), software, people, infrastructure (the physical, organizational, administrative and cultural environments that support GIS operations)

Question 4

when was the first operational GIS developed and what other events helped with the early development of GIS?

Answer 4

• by Tomlinson in the early 1960s for storing, manipulating and analyzing data collected for the Canada Land Inventory
• in 1964, Fisher founded the Harvard Laboratory for Computer Graphics
• mapping and spatial analysis were introducted at the University of Edinburgh + the Experimental Cartography Unit in the UK
• publication of Ian McHarg’s Design with Nature included map overlay method for suitability analysis
• introduction of an urban street network with topology in the US census bureau’s DIME system

Question 5

what advancements in technology helped bring GIS to mainstream use by the 1990s?

Answer 5

advent of the GUI, powerful and affordable hardware and software, public digital data

Question 6

what are 2 trends that have emerged in GIS?

Answer 6

• GIS has been increasingly integrated with other geospatial data such as satellite images and GPS data
• GIS has been linked with web mapping, web service, social media and cloud computing

Question 7

examples of applications of GIS

Answer 7

• land use planning, natural hazard assessment, wildlife habitat analysis, riptarian zone monitoring, timber management
• emergency planning, crime analysis, public health, land records management, transportation applications, precision farming, economic recovery

Question 8

examples of the integration with GIS and the internet

Answer 8

online map locators, location based services on phones for location searches, mobile GIS for field workers, mobile resource management, GPS for cars

Question 9

what are the different data models for GIS data?

Answer 9

vector data or raster data

Question 10

vector data

Answer 10

• uses points, lines, and polygons to represent spatial features or objects with a clear spatial location and boundary
• can be georelational or object-based, with or without topology, simple or composite

Question 11

georelational data model

Answer 11

stores geometries and attributes of spatial features separately

Question 12

object-based data model

Answer 12

stores geometries and attributes of spatial features in a single system

Question 13

topology

Answer 13

explicitly expresses the spatial relationships between features (ex. 2 lines meeting at a point)

Question 14

what are composite features?

Answer 14

features that are built on simple features of points, lines, and polygons and are designed for handling complex spatial relationships (ex. triangulated irregular network, dynamic segmentation)

Question 15

triangulated irregular network (TIN)

Answer 15

model that approximates the terrain with a set of nonoverlapping trianagles

Question 16

dynamic segmentation

Answer 16

combines 1-D linear measures like mileposts with 2-D projected coordinates

Question 17

raster data model

Answer 17

• uses a grid and grid cells to represent continuous fields (ex. elevation, precipitation). each cell has a value that captures the magnitiude of the field at that cell location
• requires lots of computer memory

Question 18

what is attribute data

Answer 18

describes the characteristics of spatial features

Question 19

what is data exploration

Answer 19

activities of visualizing, manipulating and querying data using maps, tables, and graphs to get a closer look at the data

Question 20

what are 2 basic data analysis tools for vector data?

Answer 20

• buffering and overlay
• buffering creates buffer zones from select features
• overlay combines the geometries and attributes of the input layers

Question 21

what are 4 basic data analysis tools for raster data?

Answer 21

• local, neighborhood, zonal, and global operations

- performed at the level of individual cells, groups of cells, or cells within the entire raster

Question 22

analyzing terrain

Answer 22

• tools to map the terrain in contours, profiles, hill shading, and 3d views
• tools to analyze the terrain’s slope, aspect and surface curvature
• viewshed analysis - determine areas visible from one or more observation points
• watershed analysis - trace water flow to delineate streams and watersheds

Question 23

spatial interpolation

Answer 23

• use points with known values to estimate values at other points (ex. kriging)

Question 24

least-cost path analysis

Answer 24

• find the least accumulated cost path in a raster (raster based, works with “virtual” paths

Question 25

network analysis

Answer 25

• find the shortest path between stops on a topological road network (vector-based, works with an existing road network)

Question 26

what is “volunteered geographic information” (VGI)

Answer 26

geographic information generated by the public using web applications and services

when VGI comes from a community or a specific group of people, that approach is public participation GIS (PPGIS) and results in community-based geographic information