Watershed magic
May 27, 2021 12:40 AM   Subscribe

A drop of rain falls in the USA and finds its way to the sea in an extraordinarily clever visualisation. One thing that stands out - all the wildlife reserves that border rivers.
posted by domdib (39 comments total) 66 users marked this as a favorite
I have questions about Green River and how it appears to go straight through the Rockies.

Also this answered a question I'd never really thought to ask about the Mississippi but that I clearly had. The Mississippi: what's its deal? Turns out the answer is "most of the United States drains into it, and you already know how important rivercraft were in the days before petrol engines".
posted by Merus at 12:52 AM on May 27 [4 favorites]

The first one I did went 6km and ended in some no-outlet lake or dried out lake bed in Wyoming. I think I'm doing it wrong!
posted by aubilenon at 1:01 AM on May 27

Tangentially: Paddle to the Sea
posted by fairmettle at 1:18 AM on May 27 [6 favorites]

aubilenon: Sounds like you clicked on the Great Divide Basin, which doesn't drain to any ocean. See also the Great Basin covering most of Nevada, western Utah, SE Oregon, and a big chunk of California.
posted by theory at 2:28 AM on May 27 [6 favorites]

I clicked on Wyoming too. A place called Arapahoe. It ended up in the Gulf via the Mississippi, but wow it took a long time.

It's a big continent! The perspective reminds me of flying over Minecraft while the terrain spawns without end. It just keeps going on and on. Australia's about the same size but mostly empty. There are places where if a raindrop fell it would stay there until it evaporates (very soon) and everyone would remember it as That Year It Rained.
posted by adept256 at 2:36 AM on May 27 [3 favorites]

The Mississippi: what's its deal?

The Mississippi is a former inland sea. Then it was a giant lake, then the USA drained it for timberland.

Yeah, the animation skips a lot of the Mississippi, which I suppose is too big and curvy for the designer to have thought about. For example, New Orleans is not on the tour.

Also, you've no option to go down the Atchafalaya, although 30 percent of the Mississippi flow goes through it, and more through other distributaries.

All of these river graphs use the same NHD system, which has arbitrarily chosen one of the passes as the end of the Mississippi-- I would hope that an animation like this could randomize it according to percentage flows, as those are well known.

Also spell check wants me to know that Atchafalaya isn't a word. Whatever.

But I guess this is why the Mississippi is in such bad shape, ecologically, and the attempts to restore it are being met with such resistance from the federal government. The USA literally cannot fathom it.
posted by eustatic at 4:27 AM on May 27 [7 favorites]

But this was useful for exploring the mines on the Amite River, so props.

The Amite has been so damaged by mining, that it creates a new channel path with every big storm. You can see the mismatch of the NHD path and the photo on this app. The Amite is absolutely wild and just eats highway bridges

No one should wonder why Denham Springs floods. Ever
posted by eustatic at 4:35 AM on May 27 [3 favorites]

The New River, which starts in the North Carolina mountains, flows northerly into West Virginia. It's older than the mountains that it crosses. It kept cutting down as the mountains slowly uplifted. Wikipedia page.

Here, on google maps, it crosses two long folds, making it obvious.

To follow it on the River Runner, put Blowing Rock NC in the search box. That's at one of the head waters.
posted by jjj606 at 5:02 AM on May 27 [12 favorites]

Very cool, but somehow didn't know the name of the St. Johns River in Florida, which was weird.
posted by saladin at 5:20 AM on May 27

If you put in Asheville, NC, you get to take the French Broad River, flowing north and then back and forth across Tennessee and into both Alabama and Kentucky before it joins up to the Mississippi. Continental divides are fun.
posted by rikschell at 5:23 AM on May 27

I think, as a rule, that if a river cuts a pass through a mountain range, it’s probably because the river was there before the mountains. I grew up near the New River, which cuts across the Appalachians from the southeast to drain into the Mississippi, but there are plenty of places along the West Virginia-Virginia border where the drainage cuts east, through the Shenandoah mountains, to drain into the James or the Potomac.

I didn’t know about the Green River cutting across the Rockies before this thread, but I’m not surprised about it. Same process, but the Rockies are younger.
posted by fantabulous timewaster at 5:43 AM on May 27

It's a neat visualization. As noted above, it highlights some of the limitations of the NHD stream layer, but I'm not sure there is another option with both more accuracy and also full coverage across the lower 48 that they could have used.
posted by Dip Flash at 5:49 AM on May 27 [1 favorite]

Heh. The thing this most helpfully visualizes is that I need a faster computer!
posted by seanmpuckett at 5:52 AM on May 27 [5 favorites]

It seems to lose track if a water course goes over the border: I dropped in North Idaho and it said the Columbia River was an "unnamed stream".
posted by The Notorious SRD at 6:11 AM on May 27 [4 favorites]

it said the Columbia River was an "unnamed stream".

It told me that the Clark Fork fed it all the way to the Pacific. And then zipped by Grand Coulee and skipped over Hanford on the way to the Wallula Gap. But this is a cool web app, and confirms that I'm not the only one interested in how watershed and drainages affect the geography of a place.
posted by St. Oops at 6:21 AM on May 27

There are a lot more divides than most people know. Two drops in my 'flat' down can go completely separate ways for hundreds of miles before they meet at the Mississippi, but you'd never know it unless you looked at drainage maps or used a tool like this. Pretty neat!
posted by SaltySalticid at 6:24 AM on May 27 [1 favorite]

There was a point in recent history, that for "security reasons" all the lakes on the US Canadian border were erased on the US side leaving straight lines on our side. Some of the out flows might not meet smaller streams. Unnamed stream, headwaters of the Colombia, might just be more "map magic." Each state used to have an accurate topo map, no more, I tell you.

I was once rolling acoss the big sky country, when, all of a sudden the land ahead changed abruptly, becoming bad land and runnels, and I realized I was seeing The Missouri Breaks, where the water flow heads into the Mississippi, it's an apt, old school Americana place name. Not forgetting Brando in that "outfit."
posted by Oyéah at 7:57 AM on May 27

Ah, I'm in the weird and wacky Red River of the North Basin, where everything starts heading sort of towards the Missouri and Mississippi but takes a hard turn north and all my maps end at the Canada border.
posted by AzraelBrown at 8:18 AM on May 27

There are a lot more divides than most people know.

One side effect of planning trips around units of the National Park Service has been learning more about these without having sought out that knowledge. The year we went to both Great Basin National Park and Yellowstone National Park we learned (A) about the existence of the Great Basin, and (2) that the Continental Divide isn't just one thing. And then a few years later we went to Glacier National Park, which cements that knowledge by having a Triple Divide Peak.
posted by fedward at 8:19 AM on May 27 [3 favorites]

Now that the site has been hugged by the internet, the engineer in me is thinking how this could have been done on the client side with a 2D array of ordinal and cardinal directions.
posted by RobotVoodooPower at 8:23 AM on May 27 [5 favorites]

The biggest OH YEAH, for divides is the one in Western PA.
posted by 922257033c4a0f3cecdbd819a46d626999d1af4a at 8:59 AM on May 27

I keep trying this but it just keeps calculating :(
posted by jacquilynne at 9:42 AM on May 27 [1 favorite]

It’s neat - rain at my house ends if at the Great Salt Lake - which I wasn’t expecting given I’m on the Wasatch backside but the flow made sense to me.

Sharing with my kids for a remote home school activity. Thanks for sharing!
posted by inflatablekiwi at 9:56 AM on May 27 [1 favorite]

Turns out the answer is "most of the United States drains into it, and you already know how important rivercraft were in the days before petrol engines".

Re the Mississippi, Father of Waters: That waterflow carries incredibly rich soil down the river. I grew up near the banks in Southern Illinois. If you drop any seed, it grows. That’s a bit hyperbolic, but I’ve never lived anywhere else where the soil just smells fertile. It’s intoxicating.
posted by Abehammerb Lincoln at 9:59 AM on May 27 [3 favorites]

Also the shortest path I could find (not surprisingly) is anywhere in. Bad Water Basin in Death Valley. 0 km travelled…..I mean it is the lowest geographic point in the US so makes sense
posted by inflatablekiwi at 10:16 AM on May 27

Sam Learner's site has some other interesting projects, too.
posted by SunSnork at 10:18 AM on May 27 [1 favorite]

I clicked on Casper, Wyoming -- where I set up camp in a Walmart parking lot on a hot afternoon, and I often regret not buying an inner tube and PFD and floating down the North Platte to a triumphant happy hour downtown, hopefully avoiding the coyotes.
posted by RobotVoodooPower at 10:19 AM on May 27 [1 favorite]

My drop ends in Lake Champlain outside of Swanton VT.
I guess border patrol stopped it.
posted by MtDewd at 10:57 AM on May 27

Very cool, but somehow didn't know the name of the St. Johns River in Florida, which was weird.
posted by saladin at 5:20 AM on May 27 [+] [!]

Yeah, a lot of missing names from segments in Louisiana as well, hit and miss.

I've looked into some of the NHD for St Johns, and apparently some of it might be scalar --there will be two copies of the same segment, which I assume are supposed to present at two different scales. One Copy is labeled with the name, the other copy may not be.

It seems like the small scale flowlines have most(?) of the labelling gaps, where a dataset has "Null" for GNIS_NAME

Here's the manual for NHD Plus from 2014

Here's a poster of how simple it is!

Does anyone know whether USGS has a citizen science effort to input these names? Like an Open Hydrology Map? if a bunch of local nerds worked on their own area, I imagine these Nulls could be resolved, although there will always be naming disagreements
posted by eustatic at 11:06 AM on May 27

Ah, as of 2018, here is a video on NHD Markup Web Application (Chrome only)
posted by eustatic at 11:09 AM on May 27

Seems it also drops a lot of industrial information? I wanted to make maps of how Shell Chemical pollutes Bayou Trepagnier, but it won't display the drainage from the Shell plant itself

Here's one for the Proposed Formosa Plastics plant, which would dump pre-production plastic waste into our catfish grounds in Des Allemands, and beyond, but also destroye the climate.

it seems like it skips the smaller flowlines

I discovered the slider, so if you want to use this in a New Orleans classroom, you have to move the slider to the right as the flight path gets to Kenner--it still jumps from kenner to the JAB in Plaquemines Parish, but at least you can sort of see the city out the corner of the map
posted by eustatic at 11:37 AM on May 27 [2 favorites]

This is a cool idea! I teach a high school class called "Water" and we discuss watersheds. This will be a fun tool to share with kids for them to explore. That said, I wish on the fly-by you could have more conspicuous city labels so students could more easily identify all the places they're floating past on their way to the sea (or inland basin...)

And I wish you could fly in reverse! Last nite I was reading a (remarkable) article on the 1921 Tulsa massacre that layered the geography and the personal stories of the massacre in an incredibly powerful way. As I often do while reading the news, I pulled up a separate tab with google maps to further explore the geography of the place. Realizing Tulsa was situated on the Arkansas River, I realized I knew next to nothing about the river. I figured it ended up in the Mississippi... but where are the headwaters? Scrolling repeatedly westward from Tulsa, across the high plains, to the Rockies, up up up... I arrived at the city with the highest elevation in the US! Thinking about places in terms of their river connection -- both downstream and up -- has slowly become an obsession of sorts for me.

And, FWIW: here's an interactive watershed map that I use with my students: your downstream path is traced in polygons, rather than a 3D fly-by, but it also shows what's upstream of you. Mouse over a point on the Mississippi and you'll get a sudden reminder of why folks might call it a Big River.
posted by Theophrastus Johnson at 12:10 PM on May 27 [4 favorites]

And then a few years later we went to Glacier National Park, which cements that knowledge by having a Triple Divide Peak.

Oh good to know - that's cool. Just played on the website with my 6 and 8 year olds on one of their last remote school lunches before school holidays (we'll be in Glacier in a few weeks to camp so that's exactly where we started), and they really liked checking different places within Glacier and see if they went to Pacific, Canada, or the Gulf. Fun.

Also its just a cool tool because the fly throughs really show how the geography changes from inside the park down through Idaho and through Washington etc. I know you can do fly through in Google Earth etc. but this is really educational and gives a reason to actually do it.
posted by inflatablekiwi at 12:13 PM on May 27 [1 favorite]

Does anyone know whether USGS has a citizen science effort to input these names?

Oh heck yes I would love that.
posted by saladin at 12:28 PM on May 27 [1 favorite]

Different view of (some of!) the same process, a world map done entirely in river basins.
posted by clew at 5:43 PM on May 27 [2 favorites]

I found the USGS citizen science effort, it s on app, or web app in chrome:


I also found an instructional YouTube link, posted above.

Happy GNISing!
posted by eustatic at 6:28 PM on May 27 [2 favorites]

MetaFilter: too big and curvy for the designer to have thought about
posted by kirkaracha at 10:23 PM on May 27 [2 favorites]

ooh ooh ooh! I helped make this possible! This tool uses the Hydro Network Linked Data Index (NLDI) to get the downstream trace, and then merges with additional NHD data. The NLDI is a tool that I helped architect and put together about 4 years ago. I have been hoping someone would make this kind of a tool ever since I was sitting in the office of one of the software developers and he showed me a sub-second response time for a downstream trace from the headwaters of the Missouri to the Gulf of Mexico.

The data needed to make this application has been available in the NHD for decades, but the key thing about the NLDI is speed and using data formats (a restful API that speaks geojson) that normal day-to-day web developers use. Previously you would have needed an ArcGIS Pro license ($$$) or knowledge of some fairly esoteric open source tools to get the data of the the proprietary file geodatabase format that it was made available in, and then a lot of additional GIS know-how to get to the point where the data could be handed off to the kinds of tools available through mapbox and others.

The flyover path is a simplified version of the flowline, because Sam Learner (the developer of this visualization) found that directly following the flowline with the simulated plane was so jittery that it makes you seasick. The challenge of course is that for large and windy rivers the flightline sometimes cuts off curves. It's not so much "too big and curvy for the designer to think about" and more "there were a number of tradeoffs that the single person who made this visualization in his free time was balancing and it doesn't work perfectly for every use case." As he noted in the readme to the code repo:
I've used mapbox to animate the downstream path, but needed to make all sorts of adjustments for elevation and bearing changes to prevent jerkiness/nausea (just moving from point to point feels a little like flying through turbulence while shaking your head side-to-side).
National-scale hydrology tools are hard, because something that works well for the Mississippi will probably not work as well for the Snake, which won't work as well for Mono Lake, which won't work as well for the Lake Champlain - Richelieu River system, which won't work well for some random small river that does some other kind of strange thing. You can see that now he is going down and fixing various hydrological challenges, such as the Snake River and the Chesapeake Bay.

With respect to cross-border hydrologic connectivity- stay tuned! I and others meet with our Canadian water data equivalents regularly. It is a long slog to make interoperable systems, but we are getting there. There is also a lot of exciting other stuff in the works as we move work to make our data access and presentation systems more user centered, interoperable, and accessible.
posted by rockindata at 11:17 AM on May 28 [12 favorites]

Montana to Louisiana. Impressive.
posted by Jacen at 3:26 PM on May 31

« Older You say you're filthy, ha! you've never starved   |   monster terror horror panic evil insanity... Newer »

You are not currently logged in. Log in or create a new account to post comments.