If you drop a pin anywhere in south london, it takes several "unknown river"s which on the map are stated clearly as the River Wandle.
The US drops seemed a lot cleaner
My favorite fact about raindrop paths/watersheds is that they determine most of the political boundary between Argentina and Chile. If the rain at a point ultimately flows to the Pacific Ocean, that point is in Chile; if it flows to the Atlantic Ocean, it is in Argentina. This is article 1 of the original boundary treaty [0] from the 19th century.
The treaty was made before the Andes were fully explored, and so it doesn't handle some interesting edges cases like the Southern Patagonian Ice Field. The field has the property that when rain falls there, it freezes and goes nowhere!
[0] https://en.wikipedia.org/wiki/Boundary_Treaty_of_1881_betwee... [1] https://en.wikipedia.org/wiki/Southern_Patagonian_Ice_Field
Tangentially related are lakes that flow out to two different oceans. Lake Isa in Yellowstone (https://en.m.wikipedia.org/wiki/Isa_Lake) is an example. Even more interesting the different sides of the lake flow to the 'wrong' oceans: the eastern side of the lake flows to the Pacific and the western to the Gulf of Mexico.
Backend seems to be unresponsive currently.
I tested it on a peak we have in Spain called 'Pico Tres Mares,' which translates to 'Three Seas Peak,' and it was nice to see that depending on which side you drop the raindrop, the water flows to the Bay of Biscay, the Atlantic, or the Mediterranean.
Nice.
Posted just a few months ago, the comments point to prior postings in last five years.
It doesn't quite always manage to reach the ocean, even when it claims it does[0]. Though I suppose in this domain The Netherlands would be the edge case of all edge cases.
I've also noticed it'll often not start the raindrop anywhere near where you click, so it's not quite anywhere in the world. Definitely most places though.
It doesn't work for me, but I'm going to assume the model does not include evaporation or ground water?
Dropped into Gulf of Mexico. Response: Finding downstream path from Unknown Territory
Damn this is soo cool! I tried it at a random place and it worked like magic! But when I tried it near my house, the website broke :D I think it doesn't handle unidentified rivers.
"Unable to find a flowpath from that location, try something else." And that's most of greater Seattle.
Timbuktu in Mali only travels 444 km!
Doesn't account for lakes
First try ends up in something called "Gulf of Mexico", what is that?
Neat!
broken now, just spins
The animation is cool but I'd like a way to disable it and just be able to see the path on the globe, then tap to another place and see that other path too. It would be OK to reload the page to clean all paths. No need to have a way to share them if there are more than one path.