Preferential pathways in catchments induce simple functioning but complex chemical transport

Preferential pathways in catchments induce simple functioning but complex chemical transport | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Preferential pathways in catchments induce simple functioning but complex chemical transport Erwin Zehe, Ralf Loritz, Axel Kleidon, Laurent Pfister, Brian Berkowitz This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4593397/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Preferential pathways are omnipresent on Earth. They play a key but often confusing role in hydrology, being seen either as a source of “simplicity” by catchment hydrologists, or of “complexity” by groundwater hydrologists. Here we use thermodynamic and information theoretical arguments in combination with field data to unravel this paradox. We show that preferential pathways reduce frictional dissipation and production thermal entropy . As this causes faster fluid flow, preferential pathways equally enlarge dissipation of head gradients and related production of mixing entropy. For the catchment water balance, we show that preferential pathways lead to a faster but also more spatially uniform dissipation of the head gradients controlling streamflow generation. This explains the success of simplified, aggregated models. Second, we show that this simplicity is only apparent: preferential pathways strongly broaden the spectrum of fluid velocities, implying that bulk water fluxes consist of a complex mixture of waters of variable ages. This complexity cannot manifest when considering the pure fluid but requires examination of chemicals to trace the travel time distribution of the water leaving the system. We conclude that preferential pathways generally increase the complexity of hydrological systems, while consideration of bulk streamflow enables a convenient but possibly misleading simplification. Earth and environmental sciences/Hydrology Earth and environmental sciences/Environmental sciences Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4593397","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":323273274,"identity":"0c493efb-5d0f-41c6-bff5-eb8e62d0e3f3","order_by":0,"name":"Erwin Zehe","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA0ElEQVRIie3OMQrCMBTG8Q8KdYl1bRHqFV7pIEKhV4kInRQc3eoBegC9RcELBDK41L2biquD0KVTMUVxbDI65D89wvvxAthsf1i6BwTQgeBI8P5JaAh9dlw1uCtwbkjwISwGjMi0iuQWLJyPiobuLUKv5sMk9dYkD/DjRXE5cfWxONARYuNSMtCyrDcnoYgazAjPy+vz0ZPclAhONXP6j6lBSyYvyUhEZZXFxDM/Ola3YZIW7qphu25GZ/kI2iSZeWfNle+t3+SbrNtsNptN1xsKI0SaGv2JGQAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0003-0155-7276","institution":"Karlsruher Institute of Technology (KIT)","correspondingAuthor":true,"prefix":"","firstName":"Erwin","middleName":"","lastName":"Zehe","suffix":""},{"id":323273275,"identity":"d3261555-4a0e-4fcf-96cc-4807b501f230","order_by":1,"name":"Ralf Loritz","email":"","orcid":"https://orcid.org/0000-0002-0540-6478","institution":"Karlsruher Institute of Technology (KIT)","correspondingAuthor":false,"prefix":"","firstName":"Ralf","middleName":"","lastName":"Loritz","suffix":""},{"id":323273276,"identity":"39237289-41f5-4617-8d0f-ec56eab64e66","order_by":2,"name":"Axel Kleidon","email":"","orcid":"https://orcid.org/0000-0002-3798-0730","institution":"Max Planck Institute for Biogeochemistry","correspondingAuthor":false,"prefix":"","firstName":"Axel","middleName":"","lastName":"Kleidon","suffix":""},{"id":323273277,"identity":"6e99966d-d647-4531-b1a2-4beab90ad16e","order_by":3,"name":"Laurent Pfister","email":"","orcid":"https://orcid.org/0000-0001-5494-5753","institution":"Luxembourg Institute of Science and Technology (LIST)","correspondingAuthor":false,"prefix":"","firstName":"Laurent","middleName":"","lastName":"Pfister","suffix":""},{"id":323273278,"identity":"2cdb2f1c-b6e5-4d3f-a8ed-f8e973f93482","order_by":4,"name":"Brian Berkowitz","email":"","orcid":"https://orcid.org/0000-0003-3078-1859","institution":"Weizmann Institute of Science","correspondingAuthor":false,"prefix":"","firstName":"Brian","middleName":"","lastName":"Berkowitz","suffix":""}],"badges":[],"createdAt":"2024-06-17 10:06:09","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4593397/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4593397/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":77074471,"identity":"51100797-d5b8-44a5-a525-3741c2b7e5df","added_by":"auto","created_at":"2025-02-24 23:28:27","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1025968,"visible":true,"origin":"","legend":"","description":"","filename":"Naturehydrologicalcomplexity17062024update.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4593397/v1_covered_2216e558-605f-47e5-b7f1-a1d0221bb393.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Preferential pathways in catchments induce simple functioning but complex chemical transport","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-4593397/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4593397/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003ePreferential pathways are omnipresent on Earth. 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