Welcome to Introduction to GIS Software: QGIS, Class 8
This is a web page that can be viewed as slides.
→ to move forward
← to go back
Introduction to GIS Software: QGIS
GISs
- view spatial data
- make maps with spatial data
- modify spatial data
- analyze spatial data
- create spatial data
GISs
- view spatial data
- make maps with spatial data
- modify spatial data
- analyze spatial data
- create spatial data
GISs
- view spatial data
- make maps with spatial data
- modify spatial data
- analyze spatial data
- create spatial data
geoprocessing
geoprocessing
functions that make new geometries based on existing ones
buffers
buffers
make a "buffer" around features
buffer distance is in the layer's projection's units
you can make negative buffers
overlay operations
Intersect
Union
Symmetric difference
usually you'll use geoprocessing functions in a chain
keep track of these as you work!
for example, let's calculate the % of each city council district within some distance of a subway entrance
buffer
intersect
dissolve
geocoding
geocoding is a business
Google's geocoding terms:
up to 2,500 geocoding requests per day
Google's geocoding terms:
"The Geocoding API may only be used in conjunction with a Google map..."
source
Yahoo's geocoding terms:
up to 2000 geocoding requests per day
Yahoo's geocoding terms:
"You must not store any results"
source
"Never mind so-called disputed places (Kashmir, the West Bank, Cyprus, etc.) all neighbourhoods are 'disputed' around the edges..."
"... Our experience has been that there are few better ways to pick a fight than to tell someone what neighbourhood they are in (and being wrong)."
Aaron Straup Cope