Blöschl, GünterBierkens, Marc F.P.Chambel, AntonioCudennec, ChristopheDestouni, GeorgiaFiori, AldoKirchner, James W.McDonnell, Jeff J.Savenije, Hubert H.G.Sivapalan, MurugesuStumpp, ChristineToth, ElenaVolpi, ElenaCarr, GemmaLupton, ClaireSalinas, JosèSzéles, BorbálaViglione, AlbertoAksoy, HafzullahAllen, Scott T.Amin, AnamAndréassian, VazkenArheimer, BeritAryal, SantoshBaker, VictorBardsley, EarlBarendrecht, Marlies H.Bartosova, AlenaBatelaan, OkkeBerghuijs, Wouter R.Beven, KeithBlume, TheresaBogaard, ThomBorges de Amorim, PabloBöttcher, Michael E.Boulet, GillesBreinl, KorbinianBrilly, MitjaBrocca, LucaBuytaert, WouterCastellarin, AttilioCastelletti, AndreaChen, XiaohongChen, YangboChen, YuanfangChifflard, PeterClaps, PierluigiClark, MartynCollins, AdrianCroke, BarryDathe, AnnetteDavid, Paula C.de Barros, Felipe P. J.de Rooij, GerritDi Baldassarre, GiulianoDriscoll, Jessica M.Düthmann, DorisDwivedi, RavindraEris, EbruFarmer, William H.Feiccabrino, JamesFerguson, GrantFerrari, EnnioFerraris, StefanoFersch, BenjaminFinger, DavidFoglia, LauraFowler, KeirnanGartsman, BorisGascoin, SimonGaume, EricGelfan, AlexanderGeris, JosieGharari, ShervanGleeson, TomGlendell, MiriamGonzalez Bevacqua, AlenaGonzález-Dugo, María P.Grimaldi, SalvatoreGupta, A. B.Guse, BjörnHan, DaweiHannah, DavidHarpold, AdrianHaun, StefanHeal, KateHelfricht, KayHerrnegger, MathewHipsey, MatthewHlaváčiková, HanaHohmann, ClaraHolko, LadislavHopkinson, ChristopherHrachowitz, MarkusIllangasekare, Tissa H.Inam, AzharInnocente, CamylaIstanbulluoglu, ErkanJarihani, BenKalantari, ZahraKalvans, AndisKhanal, SonuKhatami, SinaKiesel, JensKirkby, MikeKnoben, WouterKochanek, KrzysztofKohnova, SilviaKolechkina, AllaKrause, StefanKreamer, DavidKreibich, HeidiKunstmann, HaraldLange, HolgerLiberato, Margarida L. R.Lindquist, EricLink, TimothyLiu, JunguoLoucks, Daniel PeterLuce, CharlesMahé, GilMakarieva, OlgaMalard, JulienMashtayeva, ShamshagulMaskey, ShreedharMas-Pla, JosepMavrova-Guirguinova, MariaMazzoleni, MaurizioMernild, SebastianMisstear, Bruce DudleyMontanari, AlbertoMüller-Thomy, HannesNabizadeh, AlirezaNardi, FernandoNeal, ChristopherNesterova, NataliiaNurtaev, BakhramOdongo, VincentPanda, SubhabrataPande, SaketPang, ZhonghePapacharalampous, GeorgiaPerrin, CharlesPfister, LaurentPimentel, RafaelPolo, María J.Post, DavidPrieto Sierra, CristinaRamos, Maria-HelenaRenner, MaikReynolds, José EduardoRidolfi, ElenaRigon, RiccardoRiva, MonicaRobertson, DavidRosso, RenzoRoy, TirthankarSá, João H.M.Salvadori, GianfaustoSandells, MelSchaefli, BettinaSchumann, AndreasScolobig, AnnaSeibert, JanServat, EricShafiei, MojtabaSharma, AshishSidibe, MoussaSidle, Roy C.Skaugen, ThomasSmith, HughSpiessl, Sabine M.Stein, LinaSteinsland, IngelinStrasser, UlrichSu, BobSzolgay, JanTarboton, DavidTauro, FlaviaThirel, GuillaumeTian, FuqiangTong, RuiTussupova, KamshatTyralis, HristosUijlenhoet, Remkovan Beek, Rensvan der Ent, Ruud J.van der Ploeg, MartineVan Loon, Anne F.van Meerveld, Iljavan Nooijen, RonaldVan Oel, Pieter RVidal, Jean-Philippevon Freyberg, JanaVorogushyn, SergiyWachniew, PrzemyslawWade, AndrewWard, PhilipWesterberg, IdaWhite, ChristopherWood, Eric F.Woods, RossXu, ZongxueYilmaz, Koray K.Zhang, Yongqiang2019-07-102019-07-102019Blöschl, G, Bierkens, M F P, Chambel, A, Cudennec, C, Destouni, G, Fiori, A, Kirchner, J W, McDonnell, J J, Savenije, H H G, Sivapalan, M, Stumpp, C, Toth, E, Volpi, E, Carr, G, Lupton, C, Salinas, J, Széles, B, Viglione, A, Aksoy, H, Allen, S T, Amin, A, Andréassian, V, Arheimer, B, Aryal, S, Baker, V, Bardsley, E, Barendrecht, M H, Bartosova, A, Batelaan, O, Berghuijs, W R, Beven, K, Blume, T, Bogaard, T, Borges de Amorim, P, Böttcher, M E, Boulet, G, Breinl, K, Brilly, M, Brocca, L, Buytaert, W, Castellarin, A, Castelletti, A, Chen, X, Chen, Y, Chen, Y, Chifflard, P, Claps, P, Clark, M, Collins, A, Croke, B, Dathe, A, David, P C, de Barros, F P J, de Rooij, G, Di Baldassarre, G, Driscoll, J M, Düthmann, D, Dwivedi, R, Eris, E, Farmer, W H, Feiccabrino, J, Ferguson, G, Ferrari, E, Ferraris, S, Fersch, B, Finger, D, Foglia, L, Fowler, K, Gartsman, B, Gascoin, S, Gaume, E, Gelfan, A, Geris, J, Gharari, S, Gleeson, T, Glendell, M, Gonzalez Bevacqua, A, González-Dugo, M P, Grimaldi, S, Gupta, A B, Guse, B, Han, D, Hannah, D, Harpold, A, Haun, S, Heal, K, Helfricht, K, Herrnegger, M, Hipsey, M, Hlaváčiková, H, Hohmann, C, Holko, L, Hopkinson, C, Hrachowitz, M, Illangasekare, T H, Inam, A, Innocente, C, Istanbulluoglu, E, Jarihani, B, Kalantari, Z, Kalvans, A, Khanal, S, Khatami, S, Kiesel, J, Kirkby, M, Knoben, W, Kochanek, K, Kohnova, S, Kolechkina, A, Krause, S, Kreamer, D, Kreibich, H, Kunstmann, H, Lange, H, Liberato, M L R, Lindquist, E, Link, T, Liu, J, Loucks, D P, Luce, C, Mahé, G, Makarieva, O, Malard, J, Mashtayeva, S, Maskey, S, Mas-Pla, J, Mavrova-Guirguinova, M, Mazzoleni, M, Mernild, S, Misstear, B D, Montanari, A, Müller-Thomy, H, Nabizadeh, A, Nardi, F, Neal, C, Nesterova, N, Nurtaev, B, Odongo, V, Panda, S, Pande, S, Pang, Z, Papacharalampous, G, Perrin, C, Pfister, L, Pimentel, R, Polo, M J, Post, D, Prieto Sierra, C, Ramos, M-H, Renner, M, Reynolds, J E, Ridolfi, E, Rigon, R, Riva, M, Robertson, D, Rosso, R, Roy, T, Sá, J H M, Salvadori, G, Sandells, M, Schaefli, B, Schumann, A, Scolobig, A, Seibert, J, Servat, E, Shafiei, M, Sharma, A, Sidibe, M, Sidle, R C, Skaugen, T, Smith, H, Spiessl, S M, Stein, L, Steinsland, I, Strasser, U, Su, B, Szolgay, J, Tarboton, D, Tauro, F, Thirel, G, Tian, F, Tong, R, Tussupova, K, Tyralis, H, Uijlenhoet, R, van Beek, R, van der Ent, R J, van der Ploeg, M, Van Loon, A F, van Meerveld, I, van Nooijen, R, Van Oel, P R, Vidal, J-P, von Freyberg, J, Vorogushyn, S, Wachniew, P, Wade, A, Ward, P, Westerberg, I, White, C, Wood, E F, Woods, R, Xu, Z, Yilmaz, K K & Zhang, Y 2019, 'Twenty-three Unsolved Problems in Hydrology (UPH) : a community perspective', Hydrological Sciences Journal, vol. 64, no. 10, pp. 1141-1158. https://doi.org/10.1080/02626667.2019.16205070262-6667RIS: urn:6670BE9AFC9AAC973E53DCC5ED6DD4BFMendeley: d113c8c7-472f-319a-b4e5-b59054ec13faORCID: /0000-0003-0159-0543/work/116105636http://hdl.handle.net/2164/12542Acknowledgements We would like to thank the members of the IAHS, EGU, AGU and IAH for supporting this initiative. The LinkedIn group and overall secretariat was hosted by the IAHS, the Splinter meeting by EGU and the Vienna Catchment Science Symposium by the Vienna Doctoral Programme on Water Resource Systems (DK W1219-N28) funded by the Austrian Science Funds (FWF).192652799enghydrologyscience questionsresearch agendainterdisciplinaryknowledge gapsG Geography (General)Water Science and TechnologySupplementary DataG1Journal article10.1080/02626667.2019.1620507http://www.scopus.com/inward/record.url?scp=85068525773&partnerID=8YFLogxKhttps://www.tandfonline.com/doi/full/10.1080/02626667.2019.1620507http://www.mendeley.com/research/twentythree-unsolved-problems-hydrology-uph-community-perspective-16410