Week 07 · October 5–7
Make the map answer a question.
Study the foundations of wildfire-smoke map visualization in Lecture 6: compare state averages, work with spatial objects and layers, and choose a projection and extent suited to the question.
This week
Visual comparisons
- Read state smoke averages in a dot plot with a national reference.
- Use regional colors and facets to organize comparisons.
- Choose a dot plot or map according to the question.
Spatial foundations
- Recognize the geometry column in an sf object.
- Draw county boundaries and layer state borders with geom_sf().
- Combine county polygons into larger regions.
Projection choices
- Compare longitude–latitude and Albers displays.
- Distinguish coord_sf() from st_transform().
- Set geographic limits that make the study area readable.
Lecture slides
Research guide
When Canadian smoke crosses the border
Connect each map to the part of the research question it measures. A map of smoke exposure establishes where and when exposure occurs; interpreting health effects requires the additional evidence described in the guide.
By the end of Week 7
Review the following:
- how a dot plot compares state smoke averages with a national reference;
- how spatial data combine ordinary columns with geometry;
- how counties, states, and regions form separate map layers; and
- how projection and geographic extent affect the display.