Welcome to Advanced GIS, Lecture 10
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            Advanced GIS
            Class 10
            Please create a Mapbox account and sign into it while we wait to get started.
         
        
            
dates to remember
        
        
            
April 29 and May 6: final project presentations
        
        
            
May 10: final projects due
        
        
        
            sign up for a time to talk about your project
            source
         
        
        
        
        
            
making base maps
        
        
          there is a video of the following section
         
        
            
some webmaps use raster tiles
        
        
        
        
            
raster tiles are 256 x 256 pixel images
        
        
            
they use the same zoom, x, and y values, so they're interchangeable
        
        
            
each tile is just an image on the internet
        
        
            http://a.tile.stamen.com/toner/0/0/0.png
         
        
        
        
        
            
as you zoom in, the number of tiles quadruples
        
        
            
if you made tiles for all of zoom 18 you'd have billions of images
        
        
            that's why browsers only load what you need to see
            source
         
        
        
            
so how do you make base maps?
        
        
            
it depends!
        
        
            
in theory you can make tiles on your own
        
        
            
many mapmakers turn to Mapbox
        
        
        
            
Mapbox provides (modified) OpenStreetMap data
        
        
        
            
creating styles
        
        
          there is a video of the following section
         
        
        
        
        
        
            
like most GISs, Mapbox maps are layer-based
        
        
        
        
            
layers are grouped into similar feature types, a layer group is called a component
        
        
        
        
            
you can change all of the layers in a component simultaneously
        
        
        
        
            
or you can view the layers that make up that component
        
        
        
        
        
        
            
layers have a lot more settings than components
        
        
            
by default, a layer in a component is locked
        
        
            
you can "override" individual settings and change them
        
        
        
        
            
not sure which component or layer a feature is on?
        
        
        
        
            
click it!
        
        
        
        
        
        
            
want to see exactly which features are in a layer?
        
        
        
        
            
first, go to the layer
        
        
        
        
            
click Select Data
        
        
        
        
            
green features will appear on the map, pink are on the layer but filtered out
        
        
        
        
            
click a feature to see the data behind it
        
        
        
        
            
some settings can't be changed without "ejecting" a layer from a component
        
        
        
        
        
        
        
        
        
        
        
        
        
        
            
how should we design base maps?
        
        
            
not too differently from offline maps
        
        
            think about:
            
                - scale
 
                - hierarchy
 
                - color
 
                - symbology
 
            
         
        
            
scale
        
        
        
            color
            Think about what the colors you are using mean to the viewer.
            Use contrast to your advantage.
         
        
        
            
and consider how your data will look on top of it
        
        
        
        
        
        
            
using Mapbox tiles in Carto
        
        
          there is a video of the following section
         
        
        
        
        
        
        
        
        
        
        
          there is a video of the following section
         
        
        
        
        
        
        
        
            
adding your own data to a Mapbox style
        
        
          there is a video of the following section
         
        
            1. Upload data (such as a zipped shapefile)
            2. Add the tileset to your style
         
        
        
        
        
        
        
        
        
        
        
        
        
            but it has a pretty generous free level
            source
         
        
            by default, Glitch refreshes every time you press a key, which adds another map view
            source
         
        
            you might not want to use Mapbox tiles when coding
            source