Geospatial Visualization
School of Architecture
Dr. Timothy Norris
tnorris@miami.edu
Christopher Mader
cmader@med.miami.edu
Image: accusoft blog
Presentation of Initial Sketch
In Class Next Week
Presentation Style
  • In person zoom meeting
  • You will share your screen from the lab (either a lab machine or your machine)
  • You will open your project in the GIS software of your choice
  • You will have a maximum of 5 minutes to present
  • Your presentation will be followed by a critique/review
Presentation of Initial Sketch
In Class Next Week
Expectations/Criteria
  • outline and show project data management
  • show two data layers (not counting base map)
  • show a first draft of layout (title, legend, labels)
  • introduce the outline of your story
  • define an initial question you want to answer (ARC 594/694)
  • share any problems you encountered
  • include an aggregate data display (extra credit, not required as per syllabus)
Simplification and Selection
Classification
unknown artist (cerca 1587). Fool's Head World Map. Image from National Maritime Museum, Greenwich, London.
Quick Overview
  • Generalization
    • Selection
      - The decision of what geographic phenomena are represented on the map
    • Simplification
      - The decision of what spatial resolution will be used for representing geographic phenomena
  • Classification
    • The decision of how to display attribute information that represents geographic phenomena


Scale Matters



Purpose Matters
“Map Generalization [selection and simplification]: Little white lies and lots of them”

Monmonier, M. (1996 [1991]). How to Lie With Maps. Chicago, University of Chicago Press.
Selection

Scale matters: several examples of selection across different scales

Purpose matters: selection across constant scale where on the left physical geography is emphasized whereas on the right there is a base map good for showing attribute information of non-physical phenomena

Robinson, A. H., J. L. Morrison, et al. (1995 [1953]). Elements of Cartography, sixth edition. USA, John Wiley and Sons.
Generalization

How long is the coastline of Great Britain??

Scale Matters: for a large scale world map, the polygon on the left will be sufficient, but for a poster map of the world more detail will be necessary.
Benoît Mandelbrot (1967). "How Long Is the Coast of Britain? Statistical Self-Similarity and Fractional Dimension", Science, New Series, Vol. 156, No. 3775. (May 5, 1967), pp. 636-638.
Simplification
Too much detail gives more visual weight to the line
Too much detail will make the file size larger
Simplification
ArcMap has two common algorithms
  • Point remove
  • Bend simplify
QGIS has several tools
  • Simplify Geometries
  • GRASS - v.generalize
Classification

Classification is not always desirable

  • Attribute data directly linked to the visual variable
    - the color is linked to the data (a satellite image)
    - the size is linked to the data (a proportional symbol map)
  • For interval or ratio measurement

Classed: how many classes?

  • Clorapleth: 5-7 is recommended
  • Chorachromatic: < 7
  • How to decide on class divisions?

A non-classed proportional symbol map. Note how you automatically class them in your mind.

Classed
2008 Presidential Election by County
Mark Newman - mejn@umich.edu. Department of Physics and Center for the Study of Complex Systems, University of Michigan. Under creative commons license.
non-Classed
2008 Presidential Election by County with Linear Percentages
Mark Newman - mejn@umich.edu. Department of Physics and Center for the Study of Complex Systems, University of Michigan. Under creative commons license.
Classification
Perceptual Problems
  • Be careful with the range of sizes (above)
  • Be careful of optical illusions (right)
 
Typography and Cartography
Perhaps the second hardest part of cartography (after finding data)

 
Sans Serif
Serif
Fonts for Cartography
Gill Sans
Optima
Caslon Pro
Myriad Pro
Meridian
Kepler
Popular Design Fonts
Helvetica
Trajan
Garamond
Futura
Bodini
Frutiger
Some Terminology
More than you wanted to know, but . . .
 
Character Spacing
Kerning
  • Special spacing between characters
  • Different for each font
Word Spacing
  • Space between words

Leading
  • Space between lines
  • Can be expressed as percent of font height or points
Most design software packages allow for adjustment to kerning between individual characters in a word. This can be important for large fonts; for example poster titles.

 
Map Text Conventions
  • Think about visual hierarchy and your story
  • ALWAYS
    • Natural features (rivers, oceans, lakes, mountains) - SERIF
    • Human features (cities, roads, states, counties) - SANS SERIF
  • Generally
    • Four fonts at most, better two or three
    • Avoid bold text when possible
    • Avoid type crashes (with lines, points or any other features)
A few exercises
  • Geocoding
    > give addresses lat/long coordinates
  • Joining tables
    > attach attributes to spatial geometries
  • Creating a new layer
    > for drawing your own geographies
  • Creating a Layout
    > for printing or export
Geocoding - 1
  • list of address information, usually comma separated values (csv)
  • ArcGIS geocoding service
  • "Free" online geocoding services
    • Census.gov - somewhat accurate
    • Texas A&M - needs free account
    • geocod.io - first 1000/day free, then you pay
    • More, ... google "online geocoders"
  • in the GIS ...
    • Import as csv with lat/long coordinates as columns
    • Google "create x,y points from csv" in [GIS of choice]
Geocoding - 2
  • Public LEED Project Directory
  • Go to https://www.usgbc.org/projects
    • Filter for only Miami, explore ...
    • Note that there is address information - geospatial data!
    • Download the version already made in Box Folder
  • Go to https://geocod.io
    • Upload the xlsx file
    • Check the column selections for the geocoding process
    • Note (but do not choose) the possible enrichments
    • Create account and download geocoded data
  • in the GIS ...
    • Follow the create point methods from last week
    • Either of ArcGIS Pro or QGIS
    • Label the layer (right click layer and look for either properties or label)
Joining tables - 1
  • Census data example: attributes and geography come separate
  • Get Census data from the "US Census Bureau" (data.census.gov)
    • start at https://data.census.gov/cedsci/
    • Search and select table (poverty in Florida 2021 - 5 year ACS)
    • "Customize Table" and add geography (Census tract - Florida - All Census Tracts in Miami-Dade County)
    • look for "Download Table Data" and download (make sure S1701 is selected)
    • Explore the map tab while your download is prepared
    • When ready, return to table > click "Download"
    • use IPUMS at https://uma.pop.umn.edu/ as an alternative
  • Get geographic data from "Census Geography Program"
Joining tables - 2
  • problems with the Census webpages??
  • in the GIS ...
    • Import poverty data as csv with no geometries
      > open attribute table and note header rows
    • Import tracts from shapefile
      > open attribute table and inspect
    • The join will be based on "GEOID" (tracts) and "Geography" (csv)
      > note that you must remove the "1400000US" from the Geography column in the csv
      > find the "Field Calculator", create a new field GEOID in the csv as: right("Geography" ,11)
    • Right click the geometry layer, find "Joins" in the layer properties (ArcGIS)
      Right click the layer, select properties, look for joins (QGIS)
      > join the csv with the tracts using GEOID (tracts) and the new GEOID (csv)
    • Symbolize from layer properties
      > note many different options, explore ...
Creating a data layer
  • ArcGIS Pro
    • Find an appropriate location to create a new file in Catalog
    • Right click and choose type of layer to create
    • Specify parameters (depends on layer type)
    • From Edit panel edit layer and add a feature (draw) -> save
    • From attribute table edit fields and add one, then enter a value -> save
  • QGIS
    • Find an appropriate location to create a new file in Browser
    • Right click and choose type of layer to create
    • Specify parameters (depends on layer type) -> add a field before saving
    • Use pencil icon to edit layer and then add tool (point, polygon or line) -> right click to finish
    • Enter values for fields and then save with pencil icon
Layouts for Printing and Export
  • ArcGIS Pro
    • "Insert" Panel > New Layout (choose size)
    • Add "Map Frame" and adjust scale and size
    • add other elements: title, legend, scalebar
    • "Share" Panel > Layout > export
  • QGIS
    • Project > New Print Layout (create a name)
    • right click on page to change "Page Properties"
    • Add Item > Add Map (draw rectangle on page)
    • add other elements: title, legend, scalebar
    • Layout > Export
A few more exercises (perhaps useful for your sketch)
not recipies, but use the keywords to find help in Google
  • Use API as service
    > load online dynamic data into a GIS
    > if you use this in your sketch ...
    >> make sure to have two additional layers that you downloaded to your project directory.
  • Georeferencing
    > locating external files (mostly rasters) in geographic space
Use API as Service - 1
  • API - Application Programming Interface
    • Sharing of dynamic data across some network protocol (i.e. the internet)
    • Include "API" in your search terms (as an alternative to "shapefile")
    • Among many other data providers, Arc GIS Online provides data as APIs
    • Great for data exploration and online mapping applications
    • Not suitable for publication ready maps (hard to cite)
  • Find an API endpoint
    • Identify metadata
    • Copy the URL
    • [ sometimes not obvious ]
Use API as Service - 2
  • ArcGIS Pro
    • Add data to map -> Data From Path
    • Paste URL
  • QGIS
    • Add data to map - ArcGIS REST Server
    • Edit the URL and delete everything after .../FeatureServer
    • Paste URL
    • Click "add to map"
Georeferencing ARC GIS Pro
  • For both raster (tiff, jpg) and vector (dxf) data
  • ArcGIS Pro Raster
    • add layer to map
    • click Raster layer: find "Image" panel > georeference
    • fit to display, move, scale
    • add control points
  • ArcGIS Pro Vector
    • add layer to map
    • click CAD layer group > expand layer group > select one CAD layer
    • click "CAD Layer" panel > georeference
    • fit to display, move, scale
    • add control points
Georeferencing QGIS
  • For both raster (tiff, jpg) and vector (dxf) data
  • QGIS Vector
    • possible but a little complicated
    • google "georeference dxf QGIS"
  • QGIS Raster
    • Plugins - GDAL georeferencer
    • Raster > GDAL Georeferencer
    • add image to georeferencer
    • add control points (from map canvas)
    • Settings > Transformation Settings > (Choose Transformation Type)
    • "Play" button
    • load image in QGIS