000897476 001__ 897476 000897476 005__ 20211025171514.0 000897476 0247_ $$2doi$$a10.5194/hess-25-4887-2021 000897476 0247_ $$2ISSN$$a1027-5606 000897476 0247_ $$2ISSN$$a1607-7938 000897476 0247_ $$2Handle$$a2128/28748 000897476 0247_ $$2altmetric$$aaltmetric:113031143 000897476 0247_ $$2WOS$$aWOS:000695408400002 000897476 037__ $$aFZJ-2021-03809 000897476 082__ $$a550 000897476 1001_ $$0P:(DE-HGF)0$$aHrachowitz, Markus$$b0$$eCorresponding author 000897476 245__ $$aReduction of vegetation-accessible water storage capacity after deforestation affects catchment travel time distributions and increases young water fractions in a headwater catchment 000897476 260__ $$aKatlenburg-Lindau$$bEGU$$c2021 000897476 3367_ $$2DRIVER$$aarticle 000897476 3367_ $$2DataCite$$aOutput Types/Journal article 000897476 3367_ $$0PUB:(DE-HGF)16$$2PUB:(DE-HGF)$$aJournal Article$$bjournal$$mjournal$$s1633932580_26526 000897476 3367_ $$2BibTeX$$aARTICLE 000897476 3367_ $$2ORCID$$aJOURNAL_ARTICLE 000897476 3367_ $$00$$2EndNote$$aJournal Article 000897476 520__ $$aDeforestation can considerably affect transpiration dynamics and magnitudes at the catchment scale and thereby alter the partitioning between drainage and evaporative water fluxes released from terrestrial hydrological systems. However, it has so far remained problematic to directly link reductions in transpiration to changes in the physical properties of the system and to quantify these changes in system properties at the catchment scale. As a consequence, it is difficult to quantify the effect of deforestation on parameters of catchment-scale hydrological models. This in turn leads to substantial uncertainties in predictions of the hydrological response after deforestation but also to a poor understanding of how deforestation affects principal descriptors of catchment-scale transport, such as travel time distributions and young water fractions. The objectives of this study in the Wüstebach experimental catchment are therefore to provide a mechanistic explanation of why changes in the partitioning of water fluxes can be observed after deforestation and how this further affects the storage and release dynamics of water. More specifically, we test the hypotheses that (1) post-deforestation changes in water storage dynamics and partitioning of water fluxes are largely a direct consequence of a reduction of the catchment-scale effective vegetation-accessible water storage capacity in the unsaturated root zone (SU, max) after deforestation and that (2) the deforestation-induced reduction of SU, max affects the shape of travel time distributions and results in shifts towards higher fractions of young water in the stream. Simultaneously modelling streamflow and stable water isotope dynamics using meaningfully adjusted model parameters both for the pre- and post-deforestation periods, respectively, a hydrological model with an integrated tracer routine based on the concept of storage-age selection functions is used to track fluxes through the system and to estimate the effects of deforestation on catchment travel time distributions and young water fractions Fyw.It was found that deforestation led to a significant increase in streamflow accompanied by corresponding reductions of evaporative fluxes. This is reflected by an increase in the runoff ratio from CR=0.55 to 0.68 in the post-deforestation period despite similar climatic conditions. This reduction of evaporative fluxes could be linked to a reduction of the catchment-scale water storage volume in the unsaturated soil (SU, max) that is within the reach of active roots and thus accessible for vegetation transpiration from ∼258 mm in the pre-deforestation period to ∼101 mm in the post-deforestation period. The hydrological model, reflecting the changes in the parameter SU, max, indicated that in the post-deforestation period stream water was characterized by slightly yet statistically not significantly higher mean fractions of young water (Fyw∼0.13) than in the pre-deforestation period (Fyw∼0.12). In spite of these limited effects on the overall Fyw, changes were found for wet periods, during which post-deforestation fractions of young water increased to values Fyw∼0.37 for individual storms. Deforestation also caused a significantly increased sensitivity of young water fractions to discharge under wet conditions from dFyw/dQ=0.25to 0.36. 000897476 536__ $$0G:(DE-HGF)POF4-2173$$a2173 - Agro-biogeosystems: controls, feedbacks and impact (POF4-217)$$cPOF4-217$$fPOF IV$$x0 000897476 588__ $$aDataset connected to CrossRef, Journals: juser.fz-juelich.de 000897476 7001_ $$0P:(DE-Juel1)144847$$aStockinger, Michael$$b1 000897476 7001_ $$0P:(DE-HGF)0$$aCoenders-Gerrits, Miriam$$b2 000897476 7001_ $$00000-0001-5450-4333$$avan der Ent, Ruud$$b3 000897476 7001_ $$0P:(DE-Juel1)129440$$aBogena, Heye$$b4 000897476 7001_ $$0P:(DE-Juel1)129567$$aLücke, Andreas$$b5 000897476 7001_ $$0P:(DE-HGF)0$$aStumpp, Christine$$b6 000897476 773__ $$0PERI:(DE-600)2100610-6$$a10.5194/hess-25-4887-2021$$gVol. 25, no. 9, p. 4887 - 4915$$n9$$p4887 - 4915$$tHydrology and earth system sciences$$v25$$x1607-7938$$y2021 000897476 8564_ $$uhttps://juser.fz-juelich.de/record/897476/files/hess-25-4887-2021.pdf$$yOpenAccess 000897476 909CO $$ooai:juser.fz-juelich.de:897476$$pdnbdelivery$$pdriver$$pVDB$$popen_access$$popenaire 000897476 9101_ $$0I:(DE-HGF)0$$6P:(DE-Juel1)144847$$a Universität für Bodenkultur Wien$$b1 000897476 9101_ $$0I:(DE-HGF)0$$60000-0001-5450-4333$$a Delft University of Technology$$b3 000897476 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)129440$$aForschungszentrum Jülich$$b4$$kFZJ 000897476 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)129567$$aForschungszentrum Jülich$$b5$$kFZJ 000897476 9101_ $$0I:(DE-HGF)0$$6P:(DE-HGF)0$$a Universität für Bodenkultur Wien$$b6 000897476 9131_ $$0G:(DE-HGF)POF4-217$$1G:(DE-HGF)POF4-210$$2G:(DE-HGF)POF4-200$$3G:(DE-HGF)POF4$$4G:(DE-HGF)POF$$9G:(DE-HGF)POF4-2173$$aDE-HGF$$bForschungsbereich Erde und Umwelt$$lErde im Wandel – Unsere Zukunft nachhaltig gestalten$$vFür eine nachhaltige Bio-Ökonomie – von Ressourcen zu Produkten$$x0 000897476 9141_ $$y2021 000897476 915__ $$0StatID:(DE-HGF)0200$$2StatID$$aDBCoverage$$bSCOPUS$$d2021-01-26 000897476 915__ $$0StatID:(DE-HGF)0160$$2StatID$$aDBCoverage$$bEssential Science Indicators$$d2021-01-26 000897476 915__ $$0LIC:(DE-HGF)CCBY4$$2HGFVOC$$aCreative Commons Attribution CC BY 4.0 000897476 915__ $$0StatID:(DE-HGF)1150$$2StatID$$aDBCoverage$$bCurrent Contents - Physical, Chemical and Earth Sciences$$d2021-01-26 000897476 915__ $$0StatID:(DE-HGF)9905$$2StatID$$aIF >= 5$$bHYDROL EARTH SYST SC : 2019$$d2021-01-26 000897476 915__ $$0StatID:(DE-HGF)0501$$2StatID$$aDBCoverage$$bDOAJ Seal$$d2021-01-26 000897476 915__ $$0StatID:(DE-HGF)0500$$2StatID$$aDBCoverage$$bDOAJ$$d2021-01-26 000897476 915__ $$0StatID:(DE-HGF)0113$$2StatID$$aWoS$$bScience Citation Index Expanded$$d2021-01-26 000897476 915__ $$0StatID:(DE-HGF)0700$$2StatID$$aFees$$d2021-01-26 000897476 915__ $$0StatID:(DE-HGF)0150$$2StatID$$aDBCoverage$$bWeb of Science Core Collection$$d2021-01-26 000897476 915__ $$0StatID:(DE-HGF)0510$$2StatID$$aOpenAccess 000897476 915__ $$0StatID:(DE-HGF)0030$$2StatID$$aPeer Review$$bDOAJ : Peer review$$d2021-01-26 000897476 915__ $$0StatID:(DE-HGF)0561$$2StatID$$aArticle Processing Charges$$d2021-01-26 000897476 915__ $$0StatID:(DE-HGF)0100$$2StatID$$aJCR$$bHYDROL EARTH SYST SC : 2019$$d2021-01-26 000897476 915__ $$0StatID:(DE-HGF)0300$$2StatID$$aDBCoverage$$bMedline$$d2021-01-26 000897476 915__ $$0StatID:(DE-HGF)0199$$2StatID$$aDBCoverage$$bClarivate Analytics Master Journal List$$d2021-01-26 000897476 920__ $$lyes 000897476 9201_ $$0I:(DE-Juel1)IBG-3-20101118$$kIBG-3$$lAgrosphäre$$x0 000897476 980__ $$ajournal 000897476 980__ $$aVDB 000897476 980__ $$aUNRESTRICTED 000897476 980__ $$aI:(DE-Juel1)IBG-3-20101118 000897476 9801_ $$aFullTexts