22.03.2013 Views

Creating a Map with ArcMap - Tufts University

Creating a Map with ArcMap - Tufts University

Creating a Map with ArcMap - Tufts University

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

one file choice (e.g., 233902.sid) - open this one. (Images come in color bands, so if you chose<br />

just one of the bands, you would not be getting all the colors).<br />

• Zoom in to the orthophoto. Turn off layers above it to be able to see it.<br />

• You can display layers above the orthophoto to be somewhat transparent if you like. For example,<br />

to show land use by parcel over an orthophoto (assuming you still have parcels colored by land<br />

use), turn on the parcels and right-click on the parcels layer to get the layer properties. Go to the<br />

Display tab. Set the Transparent entry to 50 (for 50%) and press Apply to see what happens<br />

• Also add the USGS scanned quad map. Since the map was drawn at the 1:24,000 scale, it looks<br />

best on the screen at this scale as well.<br />

Now that you know how to find a worksheet ID, you can if you wish download and add more<br />

orthophotos or scanned maps (e.g., to cover all of Somerville).<br />

Using Shaded Relief images<br />

Shaded relief images are better seen than explained but they are sometimes useful for maps. MassGIS<br />

has created a shaded relief data layer for the entire state of Massachusetts – it is a very large file but is<br />

available for download if you want it (same web site as above). But we have clipped a small portion of<br />

this out to cover the Boston metro area and have put this in the GIS tutorial data set. To use it in<br />

Arc<strong>Map</strong>:<br />

• Click on the Add Data icon and navigate to the MassGIS \ Shaded_relief folder and add the<br />

shd_clip image data set. (Note: this is located in your Tutorial data folder and not on the M: drive)<br />

• If it is being covered by other data layers, turn them off for now.<br />

• Rightclick on the Shd_clip layer name and choose Zoom to Layer - this takes you to the full<br />

extent of the data layer. The Shd_clip layer is showing topography as if illuminated by the sun<br />

shining from the northwest.<br />

• Zoom in the Somerville area. Zoom in until the shaded relief starts to pixellate (you can see<br />

individual squares or grid cells) - what scale are you at?<br />

16

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!