Nicole Sharp<p><strong>Bifurcating Waterways</strong></p><p>Your typical river has a single water basin and drains along a river or two on its way to the sea. But there are a handful of rivers and lakes that don’t obey our usual expectations. Some rivers flow in two directions. Some lakes have multiple outlets, each to a separate water basin. That means that water from a single lake can wind up in two entirely different bodies of water.</p><p>The most famous example of these odd waterways is South America’s Casiquiare River, seen running north to south in the image above. This navigable river connects the Orinoco River (flowing east to west in this image) with the Rio Negro (not pictured). Since the Rio Negro eventually joins the Amazon, the Casiquiare River’s meandering, nearly-flat course connects the continent’s two largest basins: the Orinoco and the Amazon.</p><p>For more strange waterways across the Americas, check out <a href="https://doi.org/10.1029/2024WR039824" rel="nofollow noopener noreferrer" target="_blank">this review paper</a>, which describes a total of 9 such hydrological head-scratchers. (Image credit: <a href="https://www.flickr.com/photos/observacao-da-terra/31909257768/" rel="nofollow noopener noreferrer" target="_blank">Coordenação-Geral de Observação da Terra/INPE</a>; research credit: <a href="https://doi.org/10.1029/2024WR039824" rel="nofollow noopener noreferrer" target="_blank">R. Sowby and A. Siegel</a>; via <a href="https://eos.org/research-spotlights/the-rivers-that-science-says-shouldnt-exist?__readwiseLocation=" rel="nofollow noopener noreferrer" target="_blank">Eos</a>)</p><p></p><p><a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/fluid-dynamics/" target="_blank">#fluidDynamics</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/geophysics/" target="_blank">#geophysics</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/physics/" target="_blank">#physics</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/rivers/" target="_blank">#rivers</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/science/" target="_blank">#science</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/surface-hydrology/" target="_blank">#surfaceHydrology</a></p>