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WILL1E
Moderator
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# Posted: 17 Dec 2020 01:47pm
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Trying to get a topo map of my property, which is only 6 acres. I went to the USGS site and selected my land plus more. I don't really understand how to use this site to see if i can get a contour map that shows finer increments than my attached photo.
Anyone know how to do that? Would be nice if the contours were in a vector format that i could open in a drawing program.
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cjm
Member
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# Posted: 17 Dec 2020 01:58pm
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check out mytopo.com ... lots of options for size, scale, detail, tic marks, shading, etc
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gcrank1
Member
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# Posted: 17 Dec 2020 02:07pm
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Interesting!
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WILL1E
Moderator
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# Posted: 17 Dec 2020 02:57pm
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Didn't see anything better than i what i found on USGS site.
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WILL1E
Moderator
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# Posted: 17 Dec 2020 02:58pm
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I wonder if i used my GPS and just walked around my property for a couple hours if i could somehow use that tracking info to generate my own topographic data set?
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Nate R
Member
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# Posted: 17 Dec 2020 03:55pm
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Historicaerials.com will give you old aerial photos, pretty cool stuff there to see how things changed over time.
The county you're in has a GIS site with aerial photos and topo overlays, I thought they mapped 2 foot contours, which is quite a bit finer than what USGS shows. Many counties have that now.
I'll email you a link.
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rockies
Member
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# Posted: 17 Dec 2020 09:22pm
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This might help.
https://www.youtube.com/watch?v=KnyP1_-03EU
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jsahara24
Member
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# Posted: 18 Dec 2020 01:57pm
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Couples ideas...
In Pennsylvania we have online mapping that includes 2 foot contours of the whole state that you can download free into AutoCAD. I am not sure if your state does as well. If they do I would be happy to convert from CAD to PDF for you.
My county parcel viewer has 5' contours in the application along with the property lines, wetlands, soils, floodplains, etc.
USGS is typically 20' contours so probably not going to help much unless you have a lot of elevation change on your property.
Good luck..
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jsahara24
Member
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# Posted: 18 Dec 2020 01:59pm
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Quoting: WILL1E I wonder if i used my GPS and just walked around my property for a couple hours if i could somehow use that tracking info to generate my own topographic data set?
Yes, you would need to get waypoints with lat/long/elevation, then create points in AutoCAD with those waypoints. From those points you create a surface and create contours from that surface. Without CAD it is possible, but a tedious chore for sure.
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moneypitfeeder
Member
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# Posted: 31 Dec 2020 12:47pm - Edited by: moneypitfeeder
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Try this:
http://geokov.com/GMapV3/Demo/MapMaker.aspx
Zoom in to the area you want to map, then at the top left side where it says "map" drop down & select "USTopo" then you can screen grab or use your browser to print to pdf. Here's an example of the screen grab of the area where my cabin is, you can change the dimensions of the map, this size is just the default
Also, I found this part of the USGS site that should be able to let you build a vector topo map, but I can't test the template, it seems to be built for a Windows machine and I'm on a Mac. https://viewer.nationalmap.gov/tools/topotemplate/
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Houska
Member
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# Posted: 1 Jan 2021 07:41am
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Up here (Ontario), townships, counties, and provinces offer higher-resolution topo maps than our national USGS-equivalent. So look at websites for more local governments for your land. By the way, it's not always publicized as "topo maps". Quite often you will have an interactive map with things like property boundaries, zoning, etc. where there's a setting somewhere on the webpage what "basemap" you want to use, and you may be able to switch to a topo basemap there.
Since I'm a geek (the most dangerous kind, a chainsaw-wielding geek), I've actually become proficient at GIS (=mapping) software to create my own maps of our property, with topo, vegetation, trails and placemarks marked. There's really good open source software that does this called QGIS, though it does have a learning curve. You can therefore place items over top of your topo map, or even create the contours from a digital elevation model (DEM), which is a file containing elevation values for a mesh of points. Here's an excerpt of what I've made for our property.
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Houska
Member
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# Posted: 1 Jan 2021 07:48am - Edited by: Houska
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Worth noting that while you can get contour maps or DEMs with 1m (or 1-2 ft) *precision*, you may be a bit disappointed since they may not have that level of *accuracy*. The data is usually processed in automated fashion from overlapping aerial photographs, where the elevation of each point is derived from minute perspective/parallax shifts across 2 adjacent photos. There's a fair amount of smoothing that takes place, and algorithmic "guessing" to try to get actual ground elevation, removing visual interference from trees and buildings.
It all works astoundingly well for mapping out hills and valleys of a reasonable size, but don't expect your favorite 6' cliff overlooking a ravine to be represented accurately just because the DEM or contour map claims to show 1' or 2' differences.
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