30 January 2012

Topo maps

Here are some more unusual USGS topo quad maps.  The first is of Venice, LA - effectively the last town on the Mississippi River before the delta and the Gulf.  The high point on the map is the levee, along the South side of the river.  It looks like there are 2 contour lines, and the bottom of the map says they are 5 foot contours, so the levee would be a little higher than 10 feet above see level.  The rest of the maps has nearly no contour lines anywhere.  Flat, flat flat.

The second map is from an adjacent quad but has no contour lines.  Instead of labeling the contour interval at the bottom, there is simply a note that says "Entire Area Below 5 Feet".  And, in the corner you'll notice that there is no legend for roads, either.  But they still made the map. The USGS didn't say, "Oh there isn't muc land there" or "there is absolutely no topography there".  They made the maps.  And I bet these maps get used too.

Be careful, the linked images are quite large.  But if you want to go back to the source, you can head over to Libre Map to get all of the topos for Louisiana.