• ThatFembyWho@lemmy.blahaj.zone
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    7 months ago

    openstreetmaps ftw. Get that, turn on cartographic overlays (outdated scans but still useful), aerial imagery, download and import nhd data, pull up ngs website, and enjoy. Help us map rivers! Even better if you can do an actual ground survey w/ gps.

    • books@lemmy.world
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      7 months ago

      I spent way toonlong mapping our houses in my neighborhood. It’s always funny to see my work on apps, I’m like shit that street is missing houses I need to get on it.

      • ThatFembyWho@lemmy.blahaj.zone
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        7 months ago

        yeah, it’s addictive, I started with sidewalks in my neighborhood, and before I knew it, I was mapping parking zones, fire hydrants, trash cans, benches, traffic signals, speed limits, turn lanes…

        • books@lemmy.world
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          7 months ago

          What’s the best tool to map points? I walk my dog and would love to quickly drop a pin for a sewer grate or fire hydrant? Is there something I can do mobile?

    • Pantoffel@feddit.de
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      7 months ago

      Okay what is nhd and ngs? When I’m horny for aerial imagery, I’m usually browsing Landsat and Sentinel archives.

        • Pantoffel@feddit.de
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          7 months ago

          Oh thank you very much. Yes, the map viewer I often use, although I’ve only touched Landsat and Sentinel imagery.

        • ThatFembyWho@lemmy.blahaj.zone
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          7 months ago

          btw NHD data tends to be too large for JOSM to handle… my one complaint about JOSM, I feel it could be more memory efficient. Qgis can be used to process and extract large datasets, just split them up into several files per state. (You also need to merge the source files.) But it’s totally worth the pain, because you get a lot of rich, high resolution data.

          Depending on where you live, your state or city might also have open datasets available.

      • ThatFembyWho@lemmy.blahaj.zone
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        7 months ago

        Be sure to check out the osm wiki! For editing, you can use their web viewer, but I personally prefer JOSM for more advanced work. Vespucci is a great tool for mapping on your phone.

  • PoisonedPrisonPanda@discuss.tchncs.de
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    7 months ago

    I like to do this for civil constructions.

    You ever took a look an desert settlements?

    There are so many awesome things to see there, and thinking of all the little humans doing their shit there is mesmerizing.

    Kind of Sim city/sims in real life

    • ThatFembyWho@lemmy.blahaj.zone
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      7 months ago

      Agreed, I’ve learned a lot doing this. Sometimes it leads to a story, like the ruins of a federal fire watchtower that was destroyed by arson, or discovering one of the largest fisheries in the country. I’ve also noticed a lot more houses are torn down in my city than might be expected. Whole blocks are empty fields now, or maybe have one derelict house remaining.

      It’s also disturbing just how much trash people collect in their yards… and the massive wounds of foresting and strip mining.

      • Pantoffel@feddit.de
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        7 months ago

        Ugh, I was in rural china once and the uncle of my ex threw all his trash in his back yard. Disgusting. Nobody really minded though. They didn’t approve, but they didn’t confront him.

  • thebuoyancyofcitrus@beehaw.org
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    7 months ago

    Why do that when you can pull in a hydrological dataset and perform stream network analysis to find the flow path between your points of interest?

  • chiliedogg@lemmy.world
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    7 months ago

    Why follow a line when I could make a DEM from some LIDAR data, then run Aspect and Accumulation functions and dileneate watersheds?

    • KrokanteBamischijf@feddit.nl
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      7 months ago

      You’re now playing GIS DnD:

      The LiDAR dataset you’re using was scanned in a forested area and doesn’t include any secondary return data. As a result, your watersheds are occluded and the data doesn’t provide the greatest cartography.

      What do you do?

        • KrokanteBamischijf@feddit.nl
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          7 months ago

          Success! You manage to build a somewhat useful TIN from the data. Upon further inspection, the contours of the watersheds you were looking for are vaguely visible. Occlusion from the surrounding trees has had an impact on the dataset though, and it seems the noise wasn’t filtered out of the dataset properly, leaving you with the occasional ridiculously stretched triangle to work with. Generating nice vector data from this will prove challenging.

          How do you proceed?

          • chiliedogg@lemmy.world
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            7 months ago

            Knowing this isn’t old growth and that the trees have been harvested for lumber multiple times, I summon my unpaid intern and have her search for maps containing contours in a year closely following a tree harvest.

            I cast Quadrangle with a conformity bonus from my UTM state plane.

  • starman2112@sh.itjust.works
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    7 months ago

    Bro wtf where does the river come from? I tried following it upstream on gmaps but it just stops in the middle of some field. Not even a mountain or something