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The Most Detailed Map of US Waters That You've Ever Seen (2023)
- ychn114 2y ago[flagged]
- codingdave 2y agoThe detail is impressive - it even has the little 12" wide, 6" deep creek that runs through my property and the neighbors seasonal puddle/not-even-a-pond that forms in his field after heavy rains.
- eppp 2y agoIt also has a lot of features that dont exist and is missing several that do. Pretty strange. It misses a pond that is completely obvious on the lidar elevation map.
- erikerikson 2y agoI can confirm the peer message. It is missing much more significant water features (ponds/streams/marshes) on land I am intimately familiar with.
- lupusreal 2y agoI've been looking around creeks in my neighborhood and this layer is substantially less accurate than the base layer it's displaying on top of.. Not sure what's going on with this data.
- gunian 2y ago[flagged]
- rgrieselhuber 2y ago“ Water plays a central role in all our lives.” You don’t say.
- yuppiepuppie 2y agoI’d be interested to know how they gathered all that data. Given the very detailed ponds and streams that may seem invisible to our daily lives, did they really send someone out there to survey all of it? Or is this via satellite imagery or something similar?
- maxerickson 2y agoIt's derived from LIDAR scans. https://www.usgs.gov/ngp-standards-and-specifications/elevation-derived-hydrography-and-national-hydrography-datasets https://www.usgs.gov/ngp-standards-and-specifications/elevat... I'm not sure it's their best product for elevation anymore, but USGS also publishes 3dep, which is a unified layer of the best available elevation data for the US.
- qwertyuiop_ 2y agoIt’s all those “ufos” with clearly marked FAA mandated navigation lights.
- driggs 2y agoFrom high resolution Digital Elevation Models. They first compute the flow direction from every pixel; from flow direction, the compute flow accumulation at every pixel. They then filter based on some threshold for catchment area, and vectorize the flow paths. The USGS NHD+ Users Guide includes a very detailed description of the technical process: https://pubs.usgs.gov/publication/ofr20191096 https://pubs.usgs.gov/publication/ofr20191096
- SpicyUme 2y agoWeird, just spot checking a few places I know relatively well I see a few issues that seem like they would show up from that method. I wonder if there are issue in build up environments? Unfortunately that link is down for me. A collection of streams go uphill in this map where in reality I believe they flow into an underground pipe or something that drains into the lake in a different place. I wouldn't expect the underground section to be perfect, but the hill the streams ascend is ~50 feet. In another place two ponds are not shown, maybe due to dense tree cover? I believe both have water year round, but one was fenced off after a kid drowned and the owners may have filled part of it in.
- ghaff 2y agoRelatively less detail I'm sure but Raven Maps has a beautiful large laminated wall map of landforms and drainage in the continental US. https://www.ravenmaps.com/48state-drainage-landform.html https://www.ravenmaps.com/48state-drainage-landform.html
- Mistletoe 2y agoThat’s really beautiful.
- ghaff 2y agoIt really is. I just had to get everything taken off my walls (and the house basically emptied) because of smoke damage remediation. A large framed map of Boston Harbor had its glass broken. I may just replace it with this which is probably more interesting as I put things back together.
- deleted 2y ago[deleted]
- adamtaylor_13 2y agoTrying to scroll anywhere on the map crashes the website on iOS. Not sure what that’s about.
- UltraSane 2y agoIt is downloading a MASSIVE amount of data. Good stress test for browsers.
- MichaelZuo 2y agoHow can that be the case when e.g. chrome can handle opening multi-GB PDFs?
- mfro 2y agoIt appears to be streaming the data in and out to reduce ram load. On my desktop it was very laggy and had no detail for 2-4 mins and from then on I can zoom into any area and wait a few secs for the data to overlay. GPU usage is very high while rendering.
- adamtaylor_13 2y agoInterestingly though, Chrome can NOT handle a 200MB html file. Which is kind of interesting given HTML is the sole purpose of a browser. Source: Was doing some interesting data extraction work and wanted to pull tables from a 200MB HTML file but chrome always crashed after a few seconds.
- MichaelZuo 2y agoI’m not that surprised, I’ve always had the impression the whole HTML ecosystem is more amateurish than PDF.
- danesparza 2y agoNot bad. Areas like Tucson, AZ are deceptive however. The Santa Cruz "river" typically doesn't have any water in it. :-)
- labster 2y agoThe deception works well though. Some German POWs got a map of Arizona and tried to escape by rafting down the Gila River. Naturally all escapees were found in less than a week.
- SirMaster 2y agoDoesn't some of this change throughout the year? Like some rivers only run at certain times the year. If so when is this data from?
- mfro 2y agoThere are differences in representation for the mean annual flow of each waterway. Read the article.
- lupusreal 2y agoWhere do they get their ground truth from? They show a lake near me which no longer exists, as of a few years ago when the dam was removed. (OSM gets this right, FWIW.)
- eppp 2y agoLidar and some sort of algorithm probably. It seems to work ok but not perfectly and depending on your area the lidar point cloud could be almost 10 years old.
- asdasdsddd 2y agoWow the inner bay area is parch dry
- novaleaf 2y agoMore detail isn't necessarily better. I own some property and this water map repeats the same seasonal streams that exist on the state's (very old) records. they should validate with satellite data or something similar.