Wednesday, January 22, 2020

On-line topo maps with 2ft elevation lines

Home page for my county's gis website

One of my readers expressed an interest in where I found the topo maps with the 2 foot elevation contours.

They are available on my county's GIS (Geographical Information System) website.

I generally go to the Gallery page

Many, many choices
More often than not, I go to the general purpose map which offers several "base map" layers and "application" layers.
The applications layers button is the second button from the left. Clicking on that button will pop-up the menu shown. I turned on the 2ft elevation, Building Footprints and Hydrology flowlines and turned off parcels.
The base map layer button is the middle button (shown beneath the icon rich menu). I changed the base map to the 2015 Aerial Imagery. If you look at the actual map shown, you might recognize the site of the First Battle of Silver Creek described in the Seven Cows story.
But what if you don't live in Eaton County?

I think you are going to have to view the page source code and see what service they are accessing. The base-map ends at the county line but the topo lines are still shown after you scroll out of Eaton County.

I am 99% sure the person who asked me has at least one kid who has the computer savvy to do that.

5 comments:

  1. I think that you'll find that the source information is actually being hosted on Eaton County's ArcGIS web site. ArcGIS is the 800lb gorilla in the GIS (Geographic Information Systems) world. The customers who utilize ArcGIS for their mapping can customize their maps with any data that they want. States, county's, townships, cities, etc all frequently choose to use ArcGIS to present different types of data as it relates to geographic areas and features. This particular kind of mapping is not hosted by a large global or national mapping service like Google, Bing, etc. 2 ft elevation lines in our county along the Continental Divide would be a lot of lines very close together. But...none of that is to say that there isn't some kid out there with more computer savvy than me. I'm a computer guy from the Cretaceous Period.

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  2. Lidar imagery is often available now at finer res than 2 ft lines but lines help the eye, too.

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  3. Many county GIS systems now have the data.

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  4. My county has a similar system. It shows property lines and identifies owners too.
    I've never seen a 2 foot system, but like DaveS my county has considerable elevation change

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  5. USGS has a series of 7.5 minute maps - very nice, great details, plus you can see land use over time.

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