Twenty-three unsolved problems in hydrology (UPH) – a community perspective

• Blöschl, Günter ORCID Institute of Hydraulic Engineering and Water Resources Management, Vienna University of Technology, Austria
• Bierkens, Marc F.P. Department of Physical Geography, Faculty of Geosciences, Utrecht University, The Netherlands
• Chambel, Antonio Institute of Earth Sciences, Department of Geosciences, University of Évora, Portugal
• Cudennec, Christophe Agrocampus Ouest, INRA, UMR 1069 SAS, Rennes, France
• Destouni, Georgia Department of Physical Geography, Stockholm University, Sweden
• Fiori, Aldo Department of Engineering, Roma Tre University, Rome, Italy
• Kirchner, James W. Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland
• McDonnell, Jeffrey J. Global Institute for Water Security, University of Saskatchewan , Saskatoon, Canada
• Savenije, Hubert H.G. Department of Water Management, Delft University of Technology, The Netherlands
• Sivapalan, Murugesu Department of Geography and Geographic Information Science, University of Illinois at Urbana-Champaign, Urbana, USA
• Stumpp, Christine Institute for Soil Physics and Rural Water Management, University of Natural Resources and Life Sciences, Vienna, Austria
• Toth, Elena Department of Civil, Chemical, Environmental and Materials Engineering (DICAM) , University of Bologna, Bologna, Italy
• Volpi, Elena Department of Engineering, Roma Tre University, Rome, Italy
• Carr, Gemma Institute of Hydraulic Engineering and Water Resources Management, Vienna University of Technology, Austria
• Lupton, Claire IAHS Ltd, CEH Wallingford, Wallingford, UK
• Salinas, Josè Institute of Hydraulic Engineering and Water Resources Management, Vienna University of Technology, Austria
• Széles, Borbála Institute of Hydraulic Engineering and Water Resources Management, Vienna University of Technology, Austria
• Viglione, Alberto Department of Environment, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, Turin, Italy
• Aksoy, Hafzullah Department of Civil Engineering, Istanbul Technical University, Istanbul, Turkey
• Allen, Scott T. Department of Environmental Systems Science, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
• Amin, Anam Department of Land, Environment, Agriculture and Forestry (TESAF), University of Padova, Padova, Italy
• Andréassian, Vazken HYCAR Research Unit, Irstea, Antony, France
• Arheimer, Berit Swedish Meteorological and Hydrological Institute (SMHI) , Norrköping, Sweden
• Aryal, Santosh K. CSIRO Land and Water, Canberra, Australia
• Baker, Victor Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
• Bardsley, Earl Faculty of Science and Engineering, University of Waikato, Hamilton, New Zealand
• Barendrecht, Marlies H. Institute of Hydraulic Engineering and Water Resources Management, Vienna University of Technology, Austria
• Bartosova, Alena Swedish Meteorological and Hydrological Institute (SMHI) , Norrköping, Sweden
• Batelaan, Okke National Centre for Groundwater Research and Training (NCGRT), College of Science & Engineering, Flinders University, Adelaide, Australia
• Berghuijs, Wouter R. Department of Environmental Systems Science, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
• Beven, Keith Lancaster Environment Centre, Lancaster University, Lancaster, UK
• Blume, Theresa GFZ German Research Centre for Geosciences, Hydrology Section, Potsdam, Germany
• Bogaard, Thom Department of Water Management, Delft University of Technology, The Netherlands
• Borges de Amorim, Pablo Graduate Program in Environmental Engineering (PPGEA), Federal University of Santa Catarina (UFSC), Florianópolis, Brazil
• Böttcher, Michael E. Geochemistry & Isotope Biogeochemistry Group, Leibniz Institute for Baltic Sea Research (IOW), Warnemünde, Germany
• Boulet, Gilles CESBIO, Université de Toulouse, CNES/CNRS/IRD/INRA/UPS , Toulouse, France
• Breinl, Korbinian Institute of Hydraulic Engineering and Water Resources Management, Vienna University of Technology, Austria
• Brilly, Mitja Department of Environmental Engineering, Faculty of Civil Engineering and Geodesy, University of Ljubljana, Ljubljana, Slovenia
• Brocca, Luca National Research Council, Research Institute for Geo-Hydrological Protection, Perugia, Italy
• Buytaert, Wouter Department of Civil and Environmental Engineering , Imperial College London, London, UK
• Castellarin, Attilio Department of Civil, Chemical, Environmental and Materials Engineering (DICAM) , University of Bologna, Bologna, Italy
• Castelletti, Andrea Department of Electronics, Information, and Bioengineering , Politecnico di Milano, Milano, Italy
• Chen, Xiaohong Center for Water Resources and Environment, Sun Yat-sen University, Guangzhou, China
• Chen, Yangbo School of Geography and Planning, Sun Yat-sen University, Guangzhou, China
• Chen, Yuanfang College of Hydrology and Water Resources, Hohai University , Nanjing, China
• Chifflard, Peter Department of Geography, Philipps-University Marburg, Marburg, Germany
• Claps, Pierluigi Department of Environment, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, Turin, Italy
• Clark, Martyn P. Centre for Hydrology and Coldwater Laboratory , University of Saskatchewan at Canmore, Canmore, Alberta, Canada
• Collins, Adrian L. Sustainable Agriculture Sciences Department , Rothamsted Research, North Wyke, Okehampton, Devon, UK
• Croke, Barry Fenner School of Environment and Society, and Mathematical Sciences Institute, Australian National University, Canberra, Australia
• Dathe, Annette Department of Water Resources, Norwegian Institute of Bioeconomy Research, Ås, Norway
• David, Paula C. Graduate Program in Environmental Engineering (PPGEA), Federal University of Santa Catarina (UFSC), Florianópolis, Brazil
• de Barros, Felipe P. J. Sonny Astani Department of Civil and Environmental Engineering , University of Southern California, Los Angeles, CA, USA
• de Rooij, Gerrit Helmholtz Centre for Environmental Research, UFZ, Soil System Science Dept., Halle (Saale), Germany
• Di Baldassarre, Giuliano Centre of Natural Hazards and Disaster Science (CNDS), Department of Earth Sciences, Uppsala University, Uppsala, Sweden
• Driscoll, Jessica M. Water Mission Area, U.S. Geological Survey, Denver, CO, USA
• Duethmann, Doris Institute of Hydraulic Engineering and Water Resources Management, Vienna University of Technology, Austria
• Dwivedi, Ravindra Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
• Eris, Ebru Department of Civil Engineering, Ege University, Izmir, Turkey
• Farmer, William H. U.S. Geological Survey, Denver, CO, USA
• Feiccabrino, James Department of Water Resources Engineering, Lund University, Lund, Sweden
• Ferguson, Grant Department of Civil, Geological and Environmental Engineering , University of Saskatchewan, Saskatoon, Canada
• Ferrari, Ennio Department of Computer Engineering, Modeling, Electronics, and Systems Science (DIMES), University of Calabria, Rende, Italy
• Ferraris, Stefano DIST Politecnico and University of Turin , Turin, Italy
• Fersch, Benjamin Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Garmisch-Partenkirchen, Germany
• Finger, David Sustainability Institute and Forum (SIF), Reykjavik University, Reykjavik, Iceland
• Foglia, Laura Department of Land Air and Water Resources, University of California Davis, Davis, CA, USA
• Fowler, Keirnan Department of Infrastructure Engineering, University of Melbourne, Parkville, Victoria, Australia
• Gartsman, Boris Water Problems Institute, Russian Academy of Sciences (IWP RAS), Moscow, Russia
• Gascoin, Simon CESBIO, Université de Toulouse, CNES/CNRS/IRD/INRA/UPS , Toulouse, France
• Gaume, Eric Department of Geotechnics, Environment, Natural Hazards and Earth Sciences, IFSTTAR, Nantes, France
• Gelfan, Alexander Faculty of Geography, Moscow State University, Moscow, Russia
• Geris, Josie Northern Rivers Institute, School of Geosciences, University of Aberdeen, Aberdeen, UK
• Gharari, Shervan School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
• Gleeson, Tom Department of Civil Engineering and School of Earth and Ocean Sciences, University of Victoria, Victoria, Canada
• Glendell, Miriam Environmental and Biochemical Sciences Group, The James Hutton Institute, Aberdeen, Scotland, UK
• Gonzalez Bevacqua, Alena Undergraduate Programme in Sanitary and Environmental Engineering , Federal University of Santa Catarina, Florianópolis, Brazil
• González-Dugo, María P. IFAPA, Agricultural and Fisheries Research Institute of Andalusia , Córdoba, Spain
• Grimaldi, Salvatore Department of Innovation in Biological, Agri-food and Forest systems (DIBAF), Tuscia University, Viterbo, Italy
• Gupta, A. B. Department of Civil Engineering , MNIT Jaipur, India
• Guse, Björn GFZ German Research Centre for Geosciences, Hydrology Section, Potsdam, Germany
• Han, Dawei Department of Civil Engineering, University of Bristol, Bristol, UK
• Hannah, David School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston. Birmingham, UK
• Harpold, Adrian Natural Resources and Environmental Science Department, University of Nevada, Reno, USA
• Haun, Stefan Institute for Modelling Hydraulic and Environmental Systems, University of Stuttgart, Stuttgart, Germany
• Heal, Kate School of GeoSciences, University of Edinburgh, Edinburgh, UK
• Helfricht, Kay Institute for Interdisciplinary Mountain Research (IGF), Austrian Academy of Sciences (ÖAW), Innsbruck, Austria
• Herrnegger, Mathew Institute for Hydrology and Water Management, University of Natural Resources and Life Sciences, Vienna, Austria
• Hipsey, Matthew UWA School of Agriculture and Environment, The University of Western Australia, Perth, Australia
• Hlaváčiková, Hana Slovak Hydrometeorological Institute, Department of Hydrological Forecasts and Warnings, Bratislava, Slovakia
• Hohmann, Clara Wegener Center for Climate and Global Change, University of Graz, Austria
• Holko, Ladislav Institute of Hydrology, Slovak Academy of Sciences, Bratislava, Slovakia
• Hopkinson, Christopher Department of Geography, University of Lethbridge, Lethbridge, Canada
• Hrachowitz, Markus Department of Water Management, Delft University of Technology, The Netherlands
• Illangasekare, Tissa H. Center for Experimental Study of Subsurface Environmental Processes , Colorado School of Mines, Golden, CO, USA
• Inam, Azhar Department of Bioresource Engineering, McGill University, Québec, Canada
• Innocente, Camyla Graduate Program in Environmental Engineering (PPGEA), Federal University of Santa Catarina (UFSC), Florianópolis, Brazil
• Istanbulluoglu, Erkan Civil and Environmental Engineering, University of Washington, Seattle, WA, USA
• Jarihani, Ben Sustainability Research Centre, University of the Sunshine Coast, Sippy Downs, QLD, Australia
• Kalantari, Zahra Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
• Kalvans, Andis Faculty of Geography and Earth Sciences, University of Latvia, Riga, Latvia
• Khanal, Sonu FutureWater, Wageningen, The Netherlands
• Khatami, Sina Department of Infrastructure Engineering, University of Melbourne, Parkville, Victoria, Australia
• Kiesel, Jens Leibniz-Institute of Freshwater Ecology and Inland Fisheries , Department of Ecosystem Research, Berlin, Germany
• Kirkby, Mike School of Geography, University of Leeds, Leeds, UK
• Knoben, Wouter Department of Civil Engineering, University of Bristol, Bristol, UK
• Kochanek, Krzysztof Institute of Geophysics, Polish Academy of Sciences, Warsaw, Poland
• Kohnová, Silvia Department of Land and Water Resources Management, Faculty of Civil Engineering, Slovak University of Technology, Bratislava, Slovakia
• Kolechkina, Alla Department of Water Management, Delft University of Technology, The Netherlands
• Krause, Stefan School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston. Birmingham, UK
• Kreamer, David Department of Geoscience, University of Nevada, Las Vegas, NV, USA
• Kreibich, Heidi GFZ German Research Centre for Geosciences, Hydrology Section, Potsdam, Germany
• Kunstmann, Harald Institute of Geography, University of Augsburg, Germany
• Lange, Holger Department Terrestrial Ecology, Norwegian Institute of Bioeconomy Research, Ås, Norway
• Liberato, Margarida L. R. Instituto Dom Luiz (IDL), Faculdade de Ciências, Universidade de Lisboa and Universidade de Trás-os-Montes e Alto Douro (UTAD), Vila Real, Portugal
• Lindquist, Eric School of Public Service, Boise State University, Boise, ID, USA
• Link, Timothy Water Resources Program, University of Idaho, Moscow, ID, USA
• Liu, Junguo School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China
• Loucks, Daniel Peter Civil and Environmental Engineering, Cornell University, Ithaca, NY, USA
• Luce, Charles US Forest Service, Boise, ID, USA
• Mahé, Gil HSM, IRD, CNRS, Université de Montpellier, Montpellier, France
• Makarieva, Olga Melnikov Permafrost Institute, Yakutsk; St. Petersburg State University, St. Petersburg, Russia
• Malard, Julien Department of Bioresource Engineering, McGill University, Québec, Canada
• Mashtayeva, Shamshagul L. Gumilev Eurasian National University, Department of Geography, Astana, Kazakhstan
• Maskey, Shreedhar Department of Water Science and Engineering, IHE Delft Institute for Water Education, Delft, The Netherlands
• Mas-Pla, Josep GAiA-Geocamb, University of Girona, and Catalan Institute for Water Research, Spain
• Mavrova-Guirguinova, Maria University of Architecture, Civil Engineering and Geodesy , Sofia, Bulgaria
• Mazzoleni, Maurizio Centre of Natural Hazards and Disaster Science (CNDS), Department of Earth Sciences, Uppsala University, Uppsala, Sweden
• Mernild, Sebastian Geophysical Institute, University of Bergen, Bergen, Norway
• Misstear, Bruce Dudley School of Engineering, Trinity College, Dublin, Ireland
• Montanari, Alberto Department of Civil, Chemical, Environmental and Materials Engineering (DICAM) , University of Bologna, Bologna, Italy
• Müller-Thomy, Hannes Institute of Hydraulic Engineering and Water Resources Management, Vienna University of Technology, Austria
• Nabizadeh, Alireza Water Engineering Department, Shiraz University, Shiraz, Iran
• Nardi, Fernando Water Resources Research and Documentation Centre (WARREDOC), University for Foreigners of Perugia, Perugia, Italy
• Neale, Christopher Robert B. Daugherty Water for Food Global Institute at the University of Nebraska, Lincoln, NE, USA
• Nesterova, Nataliia State Hydrological Institute, St. Petersburg, St. Petersburg State University, St. Petersburg, Russia
• Nurtaev, Bakhram Freelance consultant, Frechen, Germany
• Odongo, Vincent O. Centre of Natural Hazards and Disaster Science (CNDS), Department of Earth Sciences, Uppsala University, Uppsala, Sweden
• Panda, Subhabrata Department of Soil and Water Conservation, Faculty of Agriculture, Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India
• Pande, Saket Department of Water Management, Delft University of Technology, The Netherlands
• Pang, Zhonghe Institute of Geology and Geophysics, Chinese Academy of Sciences , Beijing, China
• Papacharalampous, Georgia Department of Water Resources and Environmental Engineering , National Technical University of Athens, Zographou, Greece
• Perrin, Charles HYCAR Research Unit, Irstea, Antony, France
• Pfister, Laurent Faculty of Science, Technology and Communication, University of Luxembourg, Esch-sur-Alzette, Luxembourg
• Pimentel, Rafael Andalusian Institute for Earth System Research, University of Cordoba, Spain
• Polo, María J. Andalusian Institute for Earth System Research, University of Cordoba, Spain
• Post, David CSIRO Land and Water, Canberra, Australia
• Prieto Sierra, Cristina Environmental Hydraulics Institute “IHCantabria” , Universidad de Cantabria, Santander, Spain
• Ramos, Maria-Helena HYCAR Research Unit, Irstea, Antony, France
• Renner, Maik Biospheric Theory and Modelling Group, Max-Planck-Institute for Biogeochemistry Jena, Germany
• Reynolds, José Eduardo Centre of Natural Hazards and Disaster Science (CNDS), Department of Earth Sciences, Uppsala University, Uppsala, Sweden
• Ridolfi, Elena Centre of Natural Hazards and Disaster Science (CNDS), Department of Earth Sciences, Uppsala University, Uppsala, Sweden
• Rigon, Riccardo Università di Trento/DICAM/CUDAM , Trento, Italy
• Riva, Monica Department of Civil and Environmental Engineering, Politecnico di Milano, Milan, Italy
• Robertson, David E. CSIRO Land and Water , Clayton, VIC, Australia
• Rosso, Renzo Department of Civil and Environmental Engineering, Politecnico di Milano, Milan, Italy
• Roy, Tirthankar Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ, USA
• Sá, João H.M. Graduate Program in Environmental Engineering (PPGEA), Federal University of Santa Catarina (UFSC), Florianópolis, Brazil
• Salvadori, Gianfausto Department of Mathematics and Physics, University of Salento, Lecce, Italy
• Sandells, Mel CORES Science and Engineering Limited, Burnopfield, UK
• Schaefli, Bettina Faculty of Geosciences and Environment, University of Lausanne, Lausanne, Switzerland
• Schumann, Andreas Institute of Hydrology, Water Resources Management and Environmental Engineering, Ruhr-Universität Bochum, Germany
• Scolobig, Anna Environmental Governance and Territorial Development Institute, University of Geneva, Geneva, Switzerland
• Seibert, Jan Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
• Servat, Eric University of Montpellier , Montpellier, France
• Shafiei, Mojtaba Hydroinformatics Department, East Water and Environmental Research Institute, Mashhad, Iran
• Sharma, Ashish Civil and Environmental Engineering, The University of New South Wales, Sydney, Australia
• Sidibe, Moussa Centre for Agroecology Water and Resilience (CAWR), Coventry University, UK
• Sidle, Roy C. Mountain Societies Research Institute, University of Central Asia, Khorog, GBAO, Tajikistan
• Skaugen, Thomas Norwegian Water Resources and Energy Directorate , Norway
• Smith, Hugh Landcare Research, Palmerston North, New Zealand
• Spiessl, Sabine M. Repository Safety Department, Braunschweig, Germany
• Stein, Lina Department of Civil Engineering, University of Bristol, Bristol, UK
• Steinsland, Ingelin Department of Mathematical Sciences, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
• Strasser, Ulrich Department of Geography, University of Innsbruck, Innsbruck, Austria
• Su, Bob Faculty of Geo-Information Science and Earth Observation (ITC) , University of Twente, The Netherlands
• Szolgay, Jan Department of Land and Water Resources Management, Faculty of Civil Engineering, Slovak University of Technology, Bratislava, Slovakia
• Tarboton, David Utah Water Research Laboratory, Department of Civil and Environmental Engineering, Utah State University, Logan, UT, USA
• Tauro, Flavia Department of Innovation in Biological, Agri-food and Forest systems (DIBAF), Tuscia University, Viterbo, Italy
• Thirel, Guillaume HYCAR Research Unit, Irstea, Antony, France
• Tian, Fuqiang Institute of Hydrology and Water Resources , Tsinghua University, Beijing, China
• Tong, Rui Institute of Hydraulic Engineering and Water Resources Management, Vienna University of Technology, Austria
• Tussupova, Kamshat Department of Water Resources Engineering, Lund University, Lund, Sweden
• Tyralis, Hristos Air Force Support Command, Hellenic Air Force, Elefsina, Greece
• Uijlenhoet, Remko Department of Environmental Sciences, Wageningen University, Wageningen, The Netherlands
• van Beek, Rens Department of Physical Geography, Faculty of Geosciences, Utrecht University, The Netherlands
• van der Ent, Ruud J. Department of Water Management, Delft University of Technology, The Netherlands
• van der Ploeg, Martine Wageningen University & Research, Soil Physics and Land Management Group, Wageningen, The Netherlands
• Van Loon, Anne F. School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston. Birmingham, UK
• van Meerveld, Ilja Department of Geography, University of Zurich, Zurich, Switzerland
• van Nooijen, Ronald Department of Water Management, Delft University of Technology, The Netherlands
• van Oel, Pieter R. Department of Environmental Sciences, Wageningen University, Wageningen, The Netherlands
• Vidal, Jean-Philippe RiverLy Research Unit, Irstea, Villeurbanne, France
• von Freyberg, Jana Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland
• Vorogushyn, Sergiy GFZ German Research Centre for Geosciences, Hydrology Section, Potsdam, Germany
• Wachniew, Przemyslaw Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakow, Poland
• Wade, Andrew J. Department of Geography and Environmental Science, University of Reading, Reading, UK
• Ward, Philip Institute for Environmental Studies, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
• Westerberg, Ida K. IVL Swedish Environmental Research Institute, Stockholm, Sweden
• White, Christopher Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow, UK
• Wood, Eric F. Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ, USA
• Woods, Ross Department of Civil Engineering, University of Bristol, Bristol, UK
• Xu, Zongxue College of Water Sciences, Beijing Normal University, Beijing, China
• Yilmaz, Koray K. Department of Geological Engineering, Middle East Technical University, Ankara, Turkey
• Zhang, Yongqiang Key Lab of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Science, Beijing, China

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