### Yazar "Aksoy, Hafzullah" seçeneğine göre listele

Listeleniyor 1 - 15 / 15

###### Sayfa Başına Sonuç

###### Sıralama seçenekleri

Öğe Critical drought intensity-duration-frequency curves based on total probability theorem-coupled frequency analysis(Taylor & Francis Ltd, 2021) Aksoy, Hafzullah; Cetin, Mahmut; Eris, Ebru; Burgan, Halil Ibrahim; Cavus, Yonca; Yildirim, Isilsu; Sivapalan, MurugesuDaha fazla A methodology using the standardised precipitation index is proposed to develop critical drought intensity-duration-frequency (IDF) curves. We define dry periods within which we recognise droughts of different durations. The most severe drought for each drought duration in each year is called the critical drought. The total probability theorem-coupled frequency analysis is used to determine the best-fit probability distribution function of drought severity, which is then converted to intensity. The generalised extreme value probability distribution function is found to best fit the critical drought severity. The methodology is implemented using monthly precipitation data for a meteorological station in Turkey. The critical drought intensity decreases linearly with increasing drought duration, whereas the return period increases exponentially when the drought becomes more severe. The site-specific IDF curves furnished with an empirical relationship between the intensity and return period allow one to characterise the drought not by an index-based intensity but by its return period. This kind of presentation is physically easier to understand, in particular for stakeholders and decision makers in practice.Daha fazla Öğe Doğrusal olmayan çekilme eğrisi analizi ile karstik bölge akarsularında taban akışının ayrılması(2016) Duman, Ebru Eriş; Wittenberg, Hartmut; Aksoy, Hafzullah; Selek, Bülent; Aksu, Hakan; Yurtseven, B Ragıp; Kaya, YücelDaha fazla Akarsu kesitindeki toplam akış, dolaysız akış ve dolaylı akış (taban akışı) olmak üzere iki ana bileşene sahiptir. Taban akışı yağışsız kurak dönemlerde akarsuyu besleyen yeraltı suyu akımıdır. Taban akışının doğru tahmin edilmesi su mühendisliğinin birçok dalını ilgilendiren önemli bir konudur. Türkiye'deki akarsu havzalarının üçte biri karstik yapıya sahiptir. Bu bölgelerdeki taban akışı karstik akifer boyunca yol alan dolaylı akım bileşenidir. Mevcut su kaynaklarının önemli bir kısmının bu akarsu havzaları üzerinde bulunduğu dikkate alındığında, özellikle karstik pınar boşalımlarının önem taşıdığı akarsu havzalarında yapılacak planlamalarda taban akışının doğru olarak belirlenmesinin önemi anlaşılabilir. Bu çalışmada karstik yapıya sahip Akdeniz Bölgesindeki akarsulara doğrusal olmayan taban akışı yöntemi uygulanmıştır.Bu amaçla Manavgat Nehri ve Köprüçay üzerinde bulunan Sinanhoca, Şahapköprü ve Bolasan istasyonlarının günlük akım verileri kullanılmıştır. Doğrusal olmayan taban akışı yöntemi havza depolama hacmi (S) ile debi (Q) arasında S = aQbşeklinde verilen doğrusal olmayan hazne teorisini kullanmakta; günlük akım verilerini kullanarak çekilme eğrisinin parametrelerini akımın periyodikliğine bağlı olarak hesaplamaktadır. Çalışmanın temel amacı söz konusu yöntemle taban akışı ve buna bağlı olarak karst katkı miktarı ve mevsimsel değişimlerini elde etmektir. Çalışmada doğrusal olmayan taban akışı yöntemikullanılarak çekilme parametreleri bulunduktan sonra her bir istasyon için taban akışı miktarları hesaplanmıştır. Taban akışının toplam akışa oranı özellikle Sinanhoca akım gözlem istasyonunda %88'e kadar ulaşmıştır. Bu oran Şahapköprü ve Bolasan istasyonları için %73 ve %68 olarak tayin edilmiştirDaha fazla Öğe Düşük Akımların Frekans Analizi ve Çevresel Akış ile İlişkisi(2018) Aksoy, Hafzullah; Duman, Ebru Eriş; Önöz, Bihrat; Çetin, Mahmut; Yüce, Mehmet İshak; Selek, Bülent; Burgan, Halil İbrahimDaha fazla Yıllık akış rejiminin bir bileşeni olan düşük akımlar yılın belli zamanlarında akarsuda görülebilmektedir. Düşük akımların akarsudan su sağlanması, su kalitesi, ulaşım ve canlıların yaşamı üzerinde etkileri vardır. Bir akarsu havzasında düşük akımların uzun bir süre devam etmesi durumunda havzada kuraklığın meydana gelme olasılığı artar. Bu dönemlerde suyun ne şekilde kullanılacağına karar vermek için düşük akımların incelenmesi önem taşır. Kurak dönemlerde her türlü maksatla kullanılacak suyun miktarının belirlenmesinde bir araç olarak kullanılmak üzere düşük akım ile ilgili çalışmalar yaygın olarak yapılmaktadır. Frekans analizi bu amaçla kullanılan bir yöntemdir. Bu çalışmada, Meriç-Ergene, Gediz, Seyhan ve Ceyhan havzaları için düşük akım frekans analizi yapılmıştır. Düşük akımların frekans analizinde 2- ve 3- parametreli Gamma, log-normal ve Weibull dağılımı ile Genel Ekstrem Değer dağılımı seçilmiştir. Düşük akımları temsil etmede Meriç-Ergene, Gediz ve Ceyhan havzalarında çoğunlukla 3-parametreli log-normal dağılım, Seyhan havzasında ise 3-parametreli Weibull dağılımı ön plana çıkmıştır. Akarsuların zaman zaman kurudukları da hesaba katılarak uydurulan olasılık dağılım fonksiyonları kullanılarak düşük akım debi-süre-frekans eğrileri elde edilmiş, bu sayede akım gözlem istasyonu bazında belli dönüş aralıklarına karşı gelen beklenen düşük akımların hesaplanması mümkün olmuştur. Bu çalışmada ayrıca düşük akımlar ile çevresel akış arasında bir ilişki aranmış, genelleştirilememekle birlikte belli dönüş aralıklarındaki düşük akımların çevresel akış olarak kullanma potansiyellerinin olduğu belirlenmiştir.Daha fazla Öğe Empirical Sediment Transport Models Based on Indoor Rainfall Simulator and Erosion Flume Experimental Data(Wiley, 2017) Aksoy, Hafzullah; Eris, Ebru; Tayfur, GokmenDaha fazla Land degradation processes start with accelerated runoff and sediment delivery. In this study, rainfall-runoff induced sediment transport is investigated using data from an indoor laboratory experimental setup consisting of a rainfall simulator and an erosion flume. The data are analysed to develop empirical models using sediment discharge, slope, flow discharge, rainfall intensity and sediment size. Fine and medium sands are considered as bare soil in experiments. Four rainfall intensities (45, 65, 85 and 105mmh(-1)) are applied with combinations of lateral and longitudinal slopes of 5%, 10%, 15% and 20%. Eighty experiments are conducted. Flow is measured, and sediment within flow is separated and weighted. Experimental data are used for developing empirical models through multiple regression with parameters optimized by genetic algorithm. Results show that slope is the main contributing variable to the sediment transport over hillslopes. Accommodating variables among slope, rainfall intensity, flow discharge and median diameter of sediment as independent variables, one-variable, two-variable and four-variable models are developed considering also that higher number of parameters increases the performance of the model with higher cost of parameterization. Copyright (c) 2016 John Wiley & Sons, Ltd.Daha fazla Öğe Evaluation of an erosion-sediment transport model for a hillslope using laboratory flume data(Springer Heidelberg, 2014) Arguelles, Anya Catherine C.; Jung, MinJae; Mallari, Kristine Joy B.; Pak, GiJung; Aksoy, Hafzullah; Kavvas, Levent M.; Eris, Ebru; Yoon, JaeYoung; Lee, YoungJoon; Hong, SeonHwaDaha fazla Climate change can escalate rainfall intensity and cause further increase in sediment transport in arid lands which in turn can adversely affect water quality. Hence, there is a strong need to predict the fate of sediments in order to provide measures for sound erosion control and water quality management. The presence of microtopography on hillslopes influences processes of runoff generation and erosion, which should be taken into account to achieve more accurate modelling results. This study presents a physically based mathematical model for erosion and sediment transport coupled to one-dimensional overland flow equations that simulate rainfall-runoff generation on the rill and interrill areas of a bare hillslope. Modelling effort at such a fine resolution considering the flow connection between interrill areas and rills is rarely verified. The developed model was applied on a set of data gathered from an experimental setup where a 650 cmx136 cm erosion flume was pre-formed with a longitudinal rill and interrill having a plane geometry and was equipped with a rainfall simulator that reproduces natural rainfall characteristics. The flume can be given both longitudinal and lateral slope directions. For calibration and validation, the model was applied on the experimental results obtained from the setup of the flume having 5% lateral and 10% longitudinal slope directions under rainfall intensities of 105 and 45 mm/h, respectively. Calibration showed that the model was able to produce good results based on the R (2) (0.84) and NSE (0.80) values. The model performance was further tested through validation which also produced good statistics (R (2)=0.83, NSE=0.72). Results in terms of the sedigraphs, cumulative mass curves and performance statistics suggest that the model can be a useful and an important step towards verifying and improving mathematical models of erosion and sediment transport.Daha fazla Öğe Frequency analysis of low flows in intermittent and non-intermittent rivers from hydrological basins in Turkey(Iwa Publishing, 2019) Eris, Ebru; Aksoy, Hafzullah; Onoz, Bihrat; Cetin, Mahmut; Yuce, Mehmet Ishak; Selek, Bulent; Aksu, Hakan; Burgan, Halil Ibrahim; Esit, Musa; Yildirim, Isilsu; Karakus, Ece UnsalDaha fazla This study attempts to find out the best-fit probability distribution function to low flows using the up-to-date data of intermittent and non-intermittent rivers in four hydrological basins from different regions in Turkey. Frequency analysis of D = 1-, 7-, 14-, 30-, 90- and 273-day low flows calculated from the daily flow time series of each stream gauge was performed. Weibull (W2), Gamma (G2), Generalized Extreme Value (GEV) and Log-Normal (LN2) are selected among the 2-parameter probability distribution functions together with the Weibull (W3), Gamma (G3) and Log-Normal (LN3) from the 3-parameter probability distribution function family. Selected probability distribution functions are checked for their suitability to fit each D-day low flow sequence. LN3 mostly conforms to low flows by being the best-fit among the selected probability distribution functions in three out of four hydrological basins while W3 fits low flows in one basin. With the use of the best-fit probability distribution function, the low flow-duration-frequency curves are determined, which have the ability to provide the end-users with any D-day low flow discharge of any given return period.Daha fazla Öğe Frequency curves of high and low flows in intermittent river basins for hydrological analysis and hydraulic design(Springer, 2024) Sarigil, Gokhan; Aksoy, Hafzullah; Cavus, Yonca; Eris, EbruDaha fazla Upper and lower percentiles of Flow Duration Curves (FDCs) of daily streamflow data were investigated to develop frequency curves. Upper percentiles with exceedance probability of 1, 5 and 10% (Q1, Q5, Q10) were used for high flows, and lower percentiles with non-exceedance probability of 10, 5 and 1% (Q90, Q95, Q99) for low flows. Median value (Q50) was covered to represent the average conditions of streamflow. A mixed frequency analysis based on the total probability theorem taking zero values into account was applied for the lower percentiles of FDC. Case studies were performed for three intermittent Streamflow Gauging Stations (SGSs) from Kucuk Menderes River Basin in western Turkey. An overall assessment of results shows that the best-fit probability distribution function does not change from one SGS to another considerably for low flows while each SGS has its own probability distribution function for high flows. Upper and lower percentiles, and median value were calculated at various return periods by using the identified probability distribution functions. The calculated values were plotted in the form of frequency curves of high flow percentiles and low flow percentiles. The frequency curves have a practically significant potential use in hydrological analysis, water resources management and hydraulic design under high and low flow conditions. They are yet open to further development for regionalization and their applicability can be extended to ungauged sites in river basins.Daha fazla Öğe Laboratory experiments of sediment transport from bare soil with a rill(Taylor & Francis Ltd, 2013) Aksoy, Hafzullah; Unal, N. Erdem; Cokgor, Sevket; Gedikli, Abdullah; Yoon, Jaeyoung; Koca, Kaan; Inci, S. Boran; Eris, Ebru; Pak, GijungDaha fazla Mathematical models developed for quantification of sediment transport in hydrological watersheds require data collected through field or laboratory experiments, but these are still very rare in the literature. This study aims to collect such data at the laboratory scale. To this end, a rainfall simulator equipped with nozzles to spray rainfall was constructed, together with an erosion flume that can be given longitudinal and lateral slopes. Eighty experiments were performed, considering microtopographical features by pre-forming a rill on the soil surface before the start of each experiment. Medium and fine sands were used as soil, and four rainfall intensities (45, 65, 85 and 105 mm h(-1)) were applied in the experiments. Rainfall characteristics such as uniformity, granulometry, drop velocity and kinetic energy were evaluated; flow and sediment discharge data were collected and analysed. The analysis shows that the sediment transport rate is directly proportional to rainfall intensity and slope. In contrast, the volumetric sediment concentration stays constant and does not change with rainfall intensity unless the slope changes. These conclusions are restricted to the conditions of experiments performed under rainfall intensities between and 105 mm h(-1) for medium and fine sands in a 136-cm-wide, 650-cm-long and 17-cm-deep erosion flume with longitudinal and lateral slopes varying between 5 and 20%.Daha fazla Öğe Prediction of rainfall runoff-induced sediment load from bare land surfaces by generalized regression neural network and empirical model(Wiley, 2020) Tayfur, Gokmen; Aksoy, Hafzullah; Eris, EbruDaha fazla Based on three rainfall run-off-induced sediment transport data for bare surface experimental plots, the generalized regression neural network (GRNN) and empirical models were developed to predict sediment load. Rainfall intensity, slope, rainfall duration, soil particle median diameter, clay content of the soil, rill density and soil particle mass density constituted the input variables of the models while sediment load was the target output. the GRNN model was trained and tested. the GRNN model was found successful in predicting sediment load. Sensitivity analysis by the GRNN model revealed that slope and rainfall duration were the most sensitive parameters. in addition to the GRNN model, two empirical models were proposed: (1) in the first empirical model, all the input variables were related to the sediment load, and (2) in the second empirical model, only rainfall intensity, slope and rainfall duration were related to the sediment load. the empirical models were calibrated and validated. At the calibration stage, the coefficients and the exponents of the empirical models were obtained using the genetic algorithm optimization method. the validated empirical models were also applied to two more experimental data sets: (1) one data set was from a field experiment, and (2) one set was from a laboratory experiment. the results indicated the success of the empirical models in predicting sediment load from bare land surfaces.Daha fazla Öğe A rainfall simulator for laboratory-scale assessment of rainfall-runoff-sediment transport processes over a two-dimensional flume(Elsevier Science Bv, 2012) Aksoy, Hafzullah; Unal, N. Erdem; Cokgor, Sevket; Gedikli, Abdullah; Yoon, Jaeyoung; Koca, Kaan; Inci, S. Boran; Eris, EbruDaha fazla A rainfall simulator is an ideal tool for infiltration, soil erosion, and other related research areas for replicating the process and characteristics of natural rainfall. In this study, a laboratory-scale rainfall simulator is developed. Rainfall characteristics including the rainfall intensity and its spatial uniformity, raindrop size, raindrop velocity, and kinetic energy confirm that natural rainfall conditions are simulated with sufficient accuracy. Pressure nozzles are used to spray water corresponding to rainfall intensities ranging from 45 to 105 mm h(-1). The simulator produces rainfall with uniformity coefficient changing between 82 and 89%. The raindrops falling with an initial velocity from a height of 2.43 m have median diameters of 2.2-3.1 mm. The impact velocities of the median size raindrops deviate from their terminal velocities with a relative error between 6 and 15%. The accompanying erosion flume can be given slope up to 20% in lateral and longitudinal directions. During the experiments, flow measurement is taken from two outlets at the end of the flume to distinguish the contribution of interrill areas into rills. Experiments result in typical rainfall-induced hydrographs and sedigraphs observed under natural conditions. This shows the ability of the rainfall simulator for use in sediment transport processes over hillslopes. (c) 2012 Elsevier B.V. All rights reserved.Daha fazla Öğe Rainfall-Runoff Model Considering Microtopography Simulated in a Laboratory Erosion Flume(Springer, 2016) Aksoy, Hafzullah; Gedikli, Abdullah; Unal, N. Erdem; Yilmaz, Murat; Eris, Ebru; Yoon, Jaeyoung; Tayfur, GokmenDaha fazla A comprehensive process-based rainfall-runoff model for simulating overland flow generated in rills and on interrill areas of a hillslope is evaluated using a laboratory experimental data set. For laboratory experiments, a rainfall simulator has been constructed together with a 6.50 m x 1.36 m erosion flume that can be given adjustable slopes changing between 5 % and 20 % in both longitudinal and lateral directions. The model is calibrated and validated using experimental data of simulated rainfall intensities between 45 and 105 mm/h. Results show that the model is capable of simulating the flow coming from the rill and interrill areas. It is found that most of the flow occurs in the form of rill flow. The hillslope-scale model can be used for better prediction of overland flow at the watershed-scale; it can also be used as a building block for an associated erosion and sediment transport model.Daha fazla Öğe Soil erosion model tested on experimental data of a laboratory flume with a pre-existing rill(Elsevier, 2020) Aksoy, Hafzullah; Gedikli, Abdullah; Yilmaz, Murat; Eris, Ebru; Unal, N. Erdem; Yoon, Jaeyoung; Tayfur, GokmenDaha fazla Prediction of sediment discharge transported within flow is strongly needed in order to provide measures for a well-established erosion control and water quality management practice. Initiated by runoff generation and erosion processes sediment transport is influenced by microtopography over hillslopes of hydrological watersheds. Consideration of microtopography provides more accurate results. in this study, a process-based two-dimensional rainfall-runoff mathematical model is coupled with erosion and sediment transport component. Both the rainfall-runoff and sediment transport components make simulations in rills and over interrill areas of a bare hillslope. Models at such fine resolution are rarely verified due to the complexity of rills and interrill areas. the model was applied on a data set compiled from laboratory experiments. Erosion flume was filled with granular sand to replace a bare soil. A longitudinal rill and an interrill area were pre-formed over the soil in the flume before the simulated rainfall exerted on. the flume was given both longitudinal and lateral slopes. the simulated rainfall was changed between 45 mm/h and 105 mm/h and exerted on granular uniform fine and medium sand in the erosion flume with longitudinal and lateral slopes both changing from 5% to 20%. Calibration of the model shows that it is able to produce good results in terms of sedigraphs, which suggest also that the model might be considered an important step to verify and improve watershed scale erosion and sediment transport models.Daha fazla Öğe Spatiotemporal analysis of drought by CHIRPS precipitation estimates(Springer Wien, 2022) Aksu, Hakan; Cavus, Yonca; Aksoy, Hafzullah; Akgul, Mehmet Ali; Turker, Seyhmus; Eris, EbruDaha fazla Drought is one of the most devastating natural hazards causing considerable losses in all climatic zones of the world. It is one of the most complex and the least understood hazards at the same time because of its spatially heterogeneous and temporally variable character. Spatially dense and uniformly distributed ground-based meteorological data are needed for proper spatial and temporal drought analysis. In practice, such data are lacking in general due either to the nonexistence of ground stations or their uneven and scarce distribution over a region. This creates a great potential in the use of satellite precipitation estimates (SPEs) such as the long-period high-resolution Climate Hazards Group Infrared Precipitation with Station (CHIRPS) data in drought analysis. In this study, we aim to analyze drought over the Kucuk Menderes River Basin in the western part of Turkey by using the CHIRPS data, which were found highly correlated with precipitation in the local ground stations. The analysis was performed by considering the spatial variability and temporal change in the drought characterization based on the Standardized Precipitation Index (SPI) calculated at the 3-month (seasonal) timescale. Drought in the river basin was found to have a within-year variability from month to month, and a spatial variability over the basin in any given month. Also, an over-year variability with a decreasing trend exists, which could be considered a signal for more strengthened droughts in the future. The study eventually demonstrates how the CHIRPS SPEs could be useful in the spatial and temporal drought analysis for regions with limited ground-based meteorological data.Daha fazla Öğe Spatiotemporal analysis of meteorological drought over Kucuk Menderes River Basin in the Aegean Region of Turkey(Springer Wien, 2020) Eris, Ebru; Cavus, Yonca; Aksoy, Hafzullah; Burgan, Halil Ibrahim; Aksu, Hakan; Boyacioglu, HulyaDaha fazla Meteorological drought is analyzed both in time and space by using drought indices based on site-specific precipitation and temperature data. Departure of precipitation from its normal called in this study as the Dimensionless Precipitation Anomaly Index (DPAI) is used at annual scale, while the Standardized Precipitation Index (SPI) using precipitation and the Standardized Precipitation Evapotranspiration Index (SPEI) using precipitation and temperature are considered at monthly time scale. Five meteorological stations over Kucuk Menderes River Basin in the western part of Turkey are selected for the case study. Results are presented in the forms of drought index time series, drought risk graphs, and drought severity maps. the prolonged severe historical dry periods of the river basin are correctly identified by the drought indices. It is seen that simple tools such as the drought indices used in this study based on easily available meteorological data could explain temporal variability at a site or spatial variability over a river basin. They are therefore important not only for the scientific community dealing with drought as a research problem but also for decision-makers, stakeholders, and end-users making practice about the drought through water allocation studies and drought management plans.Daha fazla Öğe Twenty-three unsolved problems in hydrology (UPH) - a community perspective(Taylor & Francis Ltd, 2019) Bloeschl, Gunter; Bierkens, Marc F. P.; Chambel, Antonio; Cudennec, Christophe; Destouni, Georgia; Fiori, Aldo; Kirchner, James W.; McDonnell, Jeffrey J.; Savenije, Hubert H. G.; Sivapalan, Murugesu; Stumpp, Christine; Toth, Elena; Volpi, Elena; Carr, Gemma; Lupton, Claire; Salinas, Jose; Szeles, Borbala; Viglione, Alberto; Aksoy, Hafzullah; Allen, Scott T.; Amin, Anam; Andreassian, Vazken; Arheimer, Berit; Aryal, Santosh K.; Baker, Victor; Bardsley, Earl; Barendrecht, Marlies H.; Bartosova, Alena; Batelaan, Okke; Berghuijs, Wouter R.; Beven, Keith; Blume, Theresa; Bogaard, Thom; de Amorim, Pablo Borges; Boettcher, Michael E.; Boulet, Gilles; Breinl, Korbinian; Brilly, Mitja; Brocca, Luca; Buytaert, Wouter; Castellarin, Attilio; Castelletti, Andrea; Chen, Xiaohong; Chen, Yangbo; Chen, Yuanfang; Chifflard, Peter; Claps, Pierluigi; Clark, Martyn P.; Collins, Adrian L.; Croke, Barry; Dathe, Annette; David, Paula C.; de Barros, Felipe P. J.; de Rooij, Gerrit; Di Baldassarre, Giuliano; Driscoll, Jessica M.; Duethmann, Doris; Dwivedi, Ravindra; Eris, Ebru; Farmer, William H.; Feiccabrino, James; Ferguson, Grant; Ferrari, Ennio; Ferraris, Stefano; Fersch, Benjamin; Finger, David; Foglia, Laura; Fowler, Keirnan; Gartsman, Boris; Gascoin, Simon; Gaume, Eric; Gelfan, Alexander; Geris, Josie; Gharari, Shervan; Gleeson, Tom; Glendell, Miriam; Bevacqua, Alena Gonzalez; Gonzalez-Dugo, Maria P.; Grimaldi, Salvatore; Gupta, A. B.; Guse, Bjoern; Han, Dawei; Hannah, David; Harpold, Adrian; Haun, Stefan; Heal, Kate; Helfricht, Kay; Herrnegger, Mathew; Hipsey, Matthew; Hlavacikova, Hana; Hohmann, Clara; Holko, Ladislav; Hopkinson, Christopher; Hrachowitz, Markus; Illangasekare, Tissa H.; Inam, Azhar; Innocente, Camyla; Istanbulluoglu, Erkan; Jarihani, Ben; Kalantari, Zahra; Kalvans, Andis; Khanal, Sonu; Khatami, Sina; Kiesel, Jens; Kirkby, Mike; Knoben, Wouter; Kochanek, Krzysztof; Kohnova, Silvia; Kolechkina, Alla; Krause, Stefan; Kreamer, David; Kreibich, Heidi; Kunstmann, Harald; Lange, Holger; Liberato, Margarida L. R.; Lindquist, Eric; Link, Timothy; Liu, Junguo; Loucks, Daniel Peter; Luce, Charles; Mahe, Gil; Makarieva, Olga; Malard, Julien; Mashtayeva, Shamshagul; Maskey, Shreedhar; Mas-Pla, Josep; Mavrova-Guirguinova, Maria; Mazzoleni, Maurizio; Mernild, Sebastian; Misstear, Bruce Dudley; Montanari, Alberto; Mueller-Thomy, Hannes; Nabizadeh, Alireza; Nardi, Fernando; Neale, Christopher; Nesterova, Nataliia; Nurtaev, Bakhram; Odongo, Vincent O.; Panda, Subhabrata; Pande, Saket; Pang, Zhonghe; Papacharalampous, Georgia; Perrin, Charles; Pfister, Laurent; Pimentel, Rafael; Polo, Maria J.; Post, David; Sierra, Cristina Prieto; Ramos, Maria-Helena; Renner, Maik; Reynolds, Jose Eduardo; Ridolfi, Elena; Rigon, Riccardo; Riva, Monica; Robertson, David E.; Rosso, Renzo; Roy, Tirthankar; Sa, Joao H. M.; Salvadori, Gianfausto; Sandells, Mel; Schaefli, Bettina; Schumann, Andreas; Scolobig, Anna; Seibert, Jan; Servat, Eric; Shafiei, Mojtaba; Sharma, Ashish; Sidibe, Moussa; Sidle, Roy C.; Skaugen, Thomas; Smith, Hugh; Spiessl, Sabine M.; Stein, Lina; Steinsland, Ingelin; Strasser, Ulrich; Su, Bob; Szolgay, Jan; Tarboton, David; Tauro, Flavia; Thirel, Guillaume; Tian, Fuqiang; Tong, Rui; Tussupova, Kamshat; Tyralis, Hristos; Uijlenhoet, Remko; van Beek, Rens; van der Ent, Ruud J.; van der Ploeg, Martine; Van Loon, Anne F.; van Meerveld, Ilja; van Nooijen, Ronald; van Oel, Pieter R.; Vidal, Jean-Philippe; von Freyberg, Jana; Vorogushyn, Sergiy; Wachniew, Przemyslaw; Wade, Andrew J.; Ward, Philip; Westerberg, Ida K.; White, Christopher; Wood, Eric F.; Woods, Ross; Xu, Zongxue; Yilmaz, Koray K.; Zhang, YongqiangDaha fazla This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused on the process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come.Daha fazla