LAB 03: PROJECT! MAPPING THROUGH TRANSECTS > ASSIGNMENT

Lab 03 asks you to create and compose a series of sections (elevation profiles) that cut across a watershed-based area of interest (AOI). You should i) download a digital elevation model (DEM) of an AOI using the SRTM plugin,  ii) cut a series a sections through that DEM using a grid (or other linework) set to the extents of your watershed boundary, and iii) compose your sections with contextual raster and vector layers in illustrator. Your drawing should show that you’ve thought about what a section can tell us about a landscape in relation to other kinds of spatial information and media.

IMPORTANT NOTE

As you draw on the cumulative knowledge built up from these first three labs, try to begin honing in on sites, scales, and geospatial methods that that can provide a platform for your final project (and midterm presentation “pitch”-- more on this soon). Consider using this lab as an opportunity to create work more reflective of your emerging interests beyond the generic, tutorial-based workflow.


DELIVERABLES

Post an image (PNG preferred, PDF ok) of your WIP to the Work-in-Progress channel on Are.na, including a short write-up. Follow the formatting guidelines in the syllabus, and the detailed drawing and write-up guidelines below.


Drawing Guidelines



Your Work-in-Progress should feature and/or make use of the following:

• A digital elevation model (DEM) downloaded using the SRTM Downloader plugin. Make sure your DEM reflects and is appropriately scaled to the size of a watershed area of interest (AOI) derived or created from the Watershed Boundary Dataset (WBD)
  • Your AOI can be based on an original, custom watershed polygon you create (using the Watershed Boundary data provided in the Additional Data folder last week)-- just make sure you’re choosing a scale that works well with the resolution of the SRTM data we’re working with. Too large an extent will result in a DEM mosaic with a lot of tiles that may be difficult to work with due to size; too small an extent will result in a DEM that may appear low resolution. Choose wisely!

• A grid or other linework to use for cutting a series of sections/elevation profiles through your AOI

• Contextual raster or vector layers that show hydrologic and/or other data that will help the viewer make sense of what’s happening in your section 
  
  • Note that depending on the scale of your map, you may want to use more detailed hydrographic features that include lower classes of river, streams, etc. Take a look at the FFR (Free Flowing Rivers) data included in the Additional Data from last week, or brave the USGS National Hydrography Dataset through their download portal.

• A composition of your sections and contextual layers in Illustrator 

If you're ready to experiment further:

• experiment with multiple rasters overlaid on top of each other using blending modes in the Symbology > Layer Rendering > Blending mode dialogue (hint: it’s hidden all the way at the bottom, so make sure to scroll down); you can also do this in Illustrator to combine raster images and vector linework with interesting effects!

Write-up Guidelines

Same as always: Write-ups should generally offer a short (around 300 words) but critical reflection on your technical and conceptual workflow. This means thinking about your experience with the technical process, design decisions regarding tools used and graphic choices, and a broader, critical consideration of how the exercise connects to themes, genres, and questions of spatial media.

Here are a number of possible prompts to guide your reflections; you do not need to answer them directly, nor do you need to answer each one.

As you work through the tutorial, consider a set of questions regarding your  technical workflow: 

• What are the implications of choosing different hydrologic unit levels (i.e. watershed scales) for this lab?


• Why is it important to use a grid or other systematically generated linework to cut your sections?

• What additional data might you need to cut sections when working across polygonal water bodies (e.g., lakes) and linear water features (e.g., rivers)? 

 

• Are there any "break-downs" in your workflow? If so, what kinds? Are these break-downs traceable to knowledge-based constraints or tool-based constraints?

Consider a further set of questions regarding your conceptual workflow.

Recall the basic journalistic “5W+H” questions regarding the genealogies of these datasets; make sure to explore metadata and documentation when available, or track it down:

• Who made these data, and for whom?


• What exactly do these data represent?


• When was the dataset originally made? Has it been modified, or is it entirely new? How many versions have there been? Are there plans to update it?


• What geographic extents (where) does the data cover, and how are those extents determined?


• Why were these data made, and with what purposes and users in mind?


• How are the data made in the first place? How are those representations geometrically and graphically constructed from the data? How are they classified, and what are the bases for those classifications?

In light of your genealogical interrogation of the data and reflection on your technical workflow, consider:

• How do sections differ from “planimetric” representations (i.e. a view from above)? When might you want to use one over the other? When might you want to use both together?

• What kinds of spatial information and relations are represented well in section? Or represented poorly?
  

• How can sections tell stories about change through a landscape? Think about serial smaller sections that cut through a waterway at intervals compared with a single, longer section that follows a waterway.  

• Are there geographic areas of interest that are emerging for you after these first three labs and sets of readings? Where, and why?