Journal of Hydrology X最新文献

{"title":"Improvement of low flows simulation in the SASER hydrological modeling chain","authors":"Omar Cenobio-Cruz ,&nbsp;Pere Quintana-Seguí ,&nbsp;Anaïs Barella-Ortiz ,&nbsp;Ane Zabaleta ,&nbsp;Luis Garrote ,&nbsp;Roger Clavera-Gispert ,&nbsp;Florence Habets ,&nbsp;Santiago Beguería","doi":"10.1016/j.hydroa.2022.100147","DOIUrl":"10.1016/j.hydroa.2022.100147","url":null,"abstract":"<div><p>The physically-based, spatially-distributed hydrometeorological model SASER, which is based on the SURFEX LSM, is used to model the hydrological cycle in several domains in Spain and southern France. In this study, the modeled streamflows are validated in a domain centered on the Pyrenees mountain range and which includes all the surrounding river basins, including the Ebro and the Adour-Garonne, with a spatial resolution of 2.5 km. Low flows were found to be poorly simulated by the model. We present an improvement of the SASER modeling chain, which introduces a conceptual reservoir, to enhance the representation of the slow component (drainage) in the hydrological response. The reservoir introduces two new empirical parameters. First, the parameters of the conceptual reservoir model were determined on a catchment-by-catchment basis, calibrating against daily observed data from 53 hydrological stations representing near-natural conditions (local calibration). The results show, on the median value, an improvement (ΔKGE of 0.11) with respect to the reference simulation. Furthermore, the relative bias of two low-flow indices were calculated and reported a clear improvement. Secondly, a regionalization approach was used, which links physiographic information with reservoir parameters through linear equations. A genetic algorithm was used to optimize the equation coefficients through the median daily KGE. Cross-validation was used to test the regionalization approach. The median KGE improved from 0.60 (default simulation) to 0.67 (ΔKGE = 0.07) after regionalization and execution of the routing scheme, and 79 % of independent catchments showed improvement. The model with regionalized parameters had a performance, in KGE terms, very close to that of the model with locally calibrated parameters. The key benefit if the regionalization is that allow us to determine the new empirical parameter of the conceptual reservoir in basins where calibration is not possible (ungauged or human-influenced basins).</p></div>","PeriodicalId":36948,"journal":{"name":"Journal of Hydrology X","volume":"18 ","pages":"Article 100147"},"PeriodicalIF":4.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43592629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Incorporating IMERG satellite precipitation uncertainty into seasonal and peak streamflow predictions using the Hillslope Link hydrological model","authors":"Samantha H. Hartke ,&nbsp;Daniel B. Wright ,&nbsp;Felipe Quintero ,&nbsp;Aline S. Falck","doi":"10.1016/j.hydroa.2023.100148","DOIUrl":"https://doi.org/10.1016/j.hydroa.2023.100148","url":null,"abstract":"<div><p>In global applications and data sparse regions, which comprise most of the earth, hydrologic model-based flood monitoring relies on precipitation data from satellite multisensor precipitation products or numerical weather forecasts. However, these products often exhibit substantial errors during the meteorological conditions that lead to flooding, including extreme rainfall. The propagation of precipitation forcing errors to predicted runoff and streamflow is scale-dependent and requires an understanding of the autocorrelation structure of precipitation errors, since error autocorrelation impacts the accumulation of precipitation errors over space and time in hydrologic models. Previous efforts to account for satellite precipitation uncertainty in hydrologic models have demonstrated the potential for improving streamflow estimates; however, these efforts use satellite precipitation error models that rely heavily on ground reference data such as rain gages or weather radar and do not characterize the nonstationarity of precipitation error autocorrelation structures. This work evaluates a new method, the Space-Time Rainfall Error and Autocorrelation Model (STREAM), which stochastically generates possible true precipitation fields, as input to the Hillslope Link Model to generate ensemble streamflow estimates. Unlike previous error models, STREAM represents the nonstationary and anisotropic autocorrelation structure of satellite precipitation error and does not use any ground reference to do so. Ensemble streamflow predictions are compared with streamflow generated using satellite precipitation fields as well as a radar-gage precipitation dataset during peak flow events. Results demonstrate that this approach to accounting for precipitation uncertainty effectively characterizes the uncertainty in streamflow estimates and reduces the error of predicted streamflow. Streamflow ensembles forced by STREAM improve streamflow prediction nearly to the level obtained using ground-reference forcing data across basin sizes.</p></div>","PeriodicalId":36948,"journal":{"name":"Journal of Hydrology X","volume":"18 ","pages":"Article 100148"},"PeriodicalIF":4.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49737082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variably saturated dual-permeability flow modeling to assess distributed infiltration and vadose storage dynamics of a karst aquifer – The Western Mountain Aquifer in Israel and the West Bank","authors":"Lysander Bresinsky ,&nbsp;Jannes Kordilla ,&nbsp;Irina Engelhardt ,&nbsp;Yakov Livshitz ,&nbsp;Martin Sauter","doi":"10.1016/j.hydroa.2022.100143","DOIUrl":"10.1016/j.hydroa.2022.100143","url":null,"abstract":"<div><p>Available methods to quantify the recharge of karst aquifers usually rely on spatially and temporally aggregated precipitation measurements and simplified recharge models, employing transfer functions to account for the delay in infiltration and the distribution in time and space. They generally neglect the non-linear nature of infiltration dynamics through the vadose zone, characterized by dual flow behavior with slow diffuse and rapid focused recharge components. Here, we present a methodology that accounts for the physics of flow by employing a variably saturated dual-permeability flow model to simulate diffuse and preferential infiltration in a large-scale carbonate aquifer. The Western Mountain Aquifer (WMA) in Israel and the West Bank was selected as a suitable groundwater basin because of the large thickness of the vadose zone, extending over several hundred-meters, the availability of long-term data as well as the catchment size, stretching across a catchment area of circa 9000km². Together, these characteristics allow the identification and quantification of the spatio-temporal distribution of the infiltration/recharge component, assessed at the level of the groundwater table. The presented methodology allows for improved water resources planning and generalization of the results, i.e., the robustness of large-scale model results with respect to local hydraulic parameter variations and data uncertainty. Semi-arid climate regions with a highly pronounced seasonality of precipitation and intense short-duration rainfalls, such as the Mediterranean region, represent a prime study location because of the clear and pronounced recharge input signals that are not superimposed by summer rainstorms. We simulate the complex dynamics of the dual-domain infiltration and partitioning of the precipitation input signal by employing HydroGeoSphere (HGS) for transient variably saturated water flow. Flow in the limestone rock matrix and high porosity system (i.e., conduits and fractures) is modeled by overlapping individual continua based on the bulk-effective Richards’ equation with van Genuchten (VG) parameters.</p></div>","PeriodicalId":36948,"journal":{"name":"Journal of Hydrology X","volume":"18 ","pages":"Article 100143"},"PeriodicalIF":4.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44366100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using helium-4, tritium, carbon-14 and other hydrogeochemical evidence to evaluate the groundwater age distribution: The case of the Neogene aquifer, Belgium","authors":"Alberto Casillas-Trasvina ,&nbsp;Bart Rogiers ,&nbsp;Koen Beerten ,&nbsp;Joonas Pärn ,&nbsp;Laurent Wouters ,&nbsp;Kristine Walraevens","doi":"10.1016/j.hydroa.2022.100132","DOIUrl":"10.1016/j.hydroa.2022.100132","url":null,"abstract":"<div><p>Apparent groundwater age dating has been proven useful and robust in understanding water origin and mixing processes, particularly when multiple tracers are considered. However, even though now extensively used, the age tracers have not been widely applied in the general practice of flow and transport model calibration. A multi tracer-study was carried out in the Neogene aquifer in Flanders to quantify the apparent age and construct a joint interpretation for the delineation of different groundwater flow systems. This understanding is critical as part of the safety and feasibility studies for the underlying Boom Clay Formation that has been considered as a potential host rock for the geological disposal of radioactive waste. In this study, we combine evidence from tritium/helium-3 (³H/³He), helium-4 (⁴He) and radiocarbon (¹⁴C) dating as well as stable isotopic (δ¹⁸O, δ²H) and hydrochemical signatures in combination with particle tracking-based age distributions from the 3D groundwater flow model. The results of the study indicate that mixing of groundwater with young and old fractions occurs predominantly in the central part of the aquifer which is made evident by the coexistence of ³H (pre and post-bomb pulse Era), ¹⁴C and ⁴He in several groundwater samples. The mixing between water of different origin is also supported by the sampled stable isotopic and hydrochemical composition of groundwater. Particle tracking residence time results show an acceptable agreement with apparent ages derived from age tracers for young (≤100 years) and old (&gt;1000 years) groundwater. Groundwater with ages between 100 and 1000 years is likely a mixture of water with young/old fractions and shows the strongest discrepancies between advective model ages and age tracer based apparent ages. On the basis of our findings, we distinguish between three groundwater flow systems in the Neogene aquifer: i) a shallow/local flow system, with groundwater originating from modern meteoric water; ii) a deep/semi-regional flow system, characterized by old groundwater where the presence of ⁴He_rad is significant; iii) a mixed zone of groundwater flow where the recently infiltrated meteoric water mixes with discharging old groundwater. These results have helped us to refine previously proposed conceptual models for the study area and will in the end reduce uncertainties relevant to the potential future geological disposal of radioactive waste.</p></div>","PeriodicalId":36948,"journal":{"name":"Journal of Hydrology X","volume":"17 ","pages":"Article 100132"},"PeriodicalIF":4.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589915522000141/pdfft?md5=590d06b201e19f4288a06094e0c20269&pid=1-s2.0-S2589915522000141-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41734589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulating hydrologic pathway contributions in fluvial and karst settings: An evaluation of conceptual, physically-based, and deep learning modeling approaches","authors":"Admin Husic ,&nbsp;Nabil Al-Aamery ,&nbsp;James F. Fox","doi":"10.1016/j.hydroa.2022.100134","DOIUrl":"10.1016/j.hydroa.2022.100134","url":null,"abstract":"<div><p>Hydrologic models are robust tools for estimating key parameters in the management of water resources, including water inputs, storage, and pathway fluxes. The selection of process-based versus data-driven modeling structure is an important consideration, particularly as advancements in machine learning yield potential for improved model performance but at the cost of lacking physical analogues. Despite recent advancement, there exists an absence of cross-model comparison of the tradeoffs between process-based and data-driven model types in settings with varying hydrologic controls. In this study, we use physically-based (SWAT), conceptually-based (LUMP), and deep-learning (LSTM) models to simulate hydrologic pathway contributions for a fluvial watershed and a karst basin over a twenty-year period. We find that, while all models are satisfactory, the LSTM model outperformed both the SWAT and LUMP models in simulating total discharge and that the improved performance was more evident in the groundwater-dominated karst system than the surface-dominated fluvial stream. Further, the LSTM model was able to achieve this improved performance with only 10–25% of the observed time-series as training data. Regarding pathways, the LSTM model coupled with a recursive digital filter was able to successfully match the magnitude of process-based estimates of quick, intermediate, and slow flow contributions for both basins (<em>ρ</em> ranging from 0.58 to 0.71). However, the process-based models exhibited more realistic time-fractal scaling of hydrologic flow pathways compared to the LSTM model which, depending on project objectives, presents a potential drawback to the use of machine learning models for some hydrologic applications. This study demonstrates the utility and potential extraction of physical-analogues of LSTM modeling, which will be useful as deep learning approaches to hydrologic modeling become more prominent and modelers look for ways to infer physical information from data-driven predictions.</p></div>","PeriodicalId":36948,"journal":{"name":"Journal of Hydrology X","volume":"17 ","pages":"Article 100134"},"PeriodicalIF":4.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589915522000165/pdfft?md5=31e75e1d709eb33218631d5f54083cfb&pid=1-s2.0-S2589915522000165-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44365003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts of climate change on Swiss alluvial aquifers – A quantitative forecast focused on natural and artificial groundwater recharge by surface water infiltration","authors":"Jannis Epting ,&nbsp;Love Råman Vinnå ,&nbsp;Sebastiano Piccolroaz ,&nbsp;Annette Affolter ,&nbsp;Stefan Scheidler","doi":"10.1016/j.hydroa.2022.100140","DOIUrl":"10.1016/j.hydroa.2022.100140","url":null,"abstract":"<div><p>The sensitivity of future groundwater recharge and temperature development was investigated for three alluvial aquifers in the urban agglomeration of the city of Basel, Switzerland. For selected climate projections groundwater recharge and the associated temperature imprinting of aquifers, which are mainly determined by artificial groundwater recharge and infiltrating surface water, were investigated.</p><p>3D numerical groundwater flow and heat-transport modeling, allowed quantifying and differentiating between natural and artificial groundwater recharge and thermal impacts. For aquifers where the infiltration of river water is an important component in the groundwater balance, the effects of climate change will be influenced by changes in river flow and thermal regimes and also by artificial groundwater recharge of surface water. Considering all climate scenarios investigated, the net heat input from river water infiltration for the Lange Erlen case study area increases by an average of 42 % by 2055 and 62 % by 2085 compared to the reference year 2000. Together with further heat inputs, particularly by artificial groundwater recharge, the temperatures of the extracted drinking water would increase by 0.4 to 1.3 K by 2055 and 0.7 to 3.1 K by 2085. In the Hardwald case study area, the most significant heat exchange occurs by artificial groundwater recharge. As a result, and considering all climate scenarios investigated, heat loss by groundwater extraction increases by an average of 38 % during the winter months from the year 2000 to the year 2085. The increased heat input, especially in the summer months, results in a temperature increase of the extracted drinking water of 0.2 to 1.0 K by 2055 and 0.6 to 4.0 K by 2085. In the Lower Birs Valley case study area, net heat input from river water infiltration increases by an average of 42 % by 2055 and 62 % by 2085. Correspondingly, the temperatures of the extracted drinking water increase by 0.9 to 3.2 K by 2055 and by 0.3 to 5.4 K by 2085.</p><p>The quantitative assessment of climate change impacts on the groundwater resources presented allows to differentiate between hydraulic and thermal impacts of natural and artificial groundwater recharge processes. Accordingly, individual drinking water wells are exposed differently to the various components of groundwater recharge. Seasonal shifts in natural groundwater recharge processes and adaptation strategies related to artificial groundwater recharge could therefore be an important factor affecting groundwater resources in future. Moreover, increased groundwater recharge from artificial groundwater recharge systems in summer months and the interaction with surface waters during high runoff periods, which will occur more often in winter months, are likely to strongly influence groundwater recharge and temperatures.</p></div>","PeriodicalId":36948,"journal":{"name":"Journal of Hydrology X","volume":"17 ","pages":"Article 100140"},"PeriodicalIF":4.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589915522000220/pdfft?md5=14a1296f44bc52a4f91f3bd9c5a46fda&pid=1-s2.0-S2589915522000220-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48948815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation experiments comparing nonstationary design-flood adjustments based on observed annual peak flows in the conterminous United States","authors":"Jory S. Hecht ,&nbsp;Nancy A. Barth ,&nbsp;Karen R. Ryberg ,&nbsp;Angela E. Gregory","doi":"10.1016/j.hydroa.2021.100115","DOIUrl":"10.1016/j.hydroa.2021.100115","url":null,"abstract":"<div><p>While nonstationary flood frequency analysis (NSFFA) methods have proliferated, few studies have rigorously compared them for modeling changes in both the central tendency and variability of annual peak-flow series, also known as the annual maximum series (AMS), in hydrologically diverse areas. Through Monte Carlo experiments, we appraise five methods for updating estimates of 10- and 100-year floods at gauged sites using synthetic records based on sample moments and change trajectories of observed AMS in the conterminous United States (CONUS). We compare two methods that consider changes in both central tendency and variability - a Gamma generalized linear model estimated with weighted least squares and the Generalized Additive Model for Location, Scale, Shape (GAMLSS) - with a distribution-free approach (quantile regression), and baseline cases assuming stationarity or only changes in central tendency.</p><p>‘Trend-space’ plots identify realistic AMS changes for which modeling trends in both central tendency and variability were warranted based on fractional root mean squared errors (fRMSE). They also reveal statistical properties of AMS under which NSFFA models perform especially well or poorly. For instance, quantile regression performed especially well (poorly) under strong negative (positive) skewness. Although the nonstationary LP3 distribution accommodates most AMS with trends well, the sensitivity of NSFFA model performance to different sample moments and trends suggests the need for more flexibility in prescribing design-flood adjustments in the CONUS. A follow-up comparison of regional NSFFA models pooling at-site AMS would further illuminate NSFFA guidance, especially for AMS with properties less conducive to NSFFA modeling, such as positive skewness and increasing variability.</p></div>","PeriodicalId":36948,"journal":{"name":"Journal of Hydrology X","volume":"17 ","pages":"Article 100115"},"PeriodicalIF":4.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589915521000432/pdfft?md5=76d304ec8d5d3bb4160123df0d529c61&pid=1-s2.0-S2589915521000432-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42963510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adapting classical water quality diagrams for ecohydrological and policy applications","authors":"Paul Schot ,&nbsp;Jack Beard ,&nbsp;Riki Hissink ,&nbsp;Michael Silberbauer ,&nbsp;Jasper Griffioen","doi":"10.1016/j.hydroa.2022.100137","DOIUrl":"10.1016/j.hydroa.2022.100137","url":null,"abstract":"<div><p>Ecological values of water have gained increasing attention over the past decades in both (eco)hydrological research and water resources management. Water quality is an important ecological steering variable, and graphical water quality diagrams may aid in rapid interpretation of the hydrochemical status of a site. Traditionally used water quality diagrams for showing multiple variables (e.g. Stiff, Maucha) were developed primarily for hydrogeological purposes, with limited information on ecologically relevant nutrient parameters.</p><p>This paper presents adapted classical water quality diagrams that retain the traditional information on ions for hydrogeological characterization, and additionally provide information on nutrients for ecological water quality characterization.</p><p>A scaling factor is used for the minor ions to visually get them across more equally compared to the macro-ion ions in the water quality diagram. Scaling of minor ions is presented based on average concentrations, as well as on water quality policy norms. Four different water quality diagrams are presented, all with the same ions included, but with different appearances to suit different preferences of individual users. Regional, national and continental scale data are used to illustrate how the different diagrams show spatial and temporal water quality characteristics.</p><p>The adapted diagrams are innovative with respect to adding comprehensive visual information on the four ecohydrologically relevant nutrient species levels (NO₃, NH₄, PO₄, K), advanced insight in redox status from the combination of four redox sensitive parameters (Fe, NO₃, SO₄, NH₄) and the option to scale minor ions relative to average measured concentrations or to water quality policy norms. Using policy norms for scaling has the advantage of providing an ‘alarm function’ of exceedance of norms when concentrations surpass the ring used in the diagram. We discuss possible standardisation of scaling factors to enable comparability between sites.</p></div>","PeriodicalId":36948,"journal":{"name":"Journal of Hydrology X","volume":"17 ","pages":"Article 100137"},"PeriodicalIF":4.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589915522000190/pdfft?md5=3689256ccdde43cc3615e9ee42e862e7&pid=1-s2.0-S2589915522000190-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42738216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From basin-scale groundwater flow to integrated geofluid research in the hydrogeology research group of Eötvös Loránd University, Hungary","authors":"Brigitta Czauner ,&nbsp;Anita Erőss ,&nbsp;Szilvia Szkolnikovics-Simon ,&nbsp;Ábel Markó ,&nbsp;Petra Baják ,&nbsp;Tímea Trásy-Havril ,&nbsp;Márk Szijártó ,&nbsp;Zsóka Szabó ,&nbsp;Katalin Hegedűs-Csondor ,&nbsp;Judit Mádl-Szőnyi","doi":"10.1016/j.hydroa.2022.100142","DOIUrl":"10.1016/j.hydroa.2022.100142","url":null,"abstract":"<div><p>This review paper briefly summarizes the research results of the majority (∼70%) women team of the Hydrogeology Research Group of Eötvös Loránd University, Hungary, led by Judit Mádl-Szőnyi. The group had originally focused on basin-scale groundwater flow systems and the related processes and phenomena but extended its research activity to other geofluids in answer to global challenges such as the water crisis, climate change, and energy transition. However, the core concept of these studies remained the basin-scale system approach of groundwater flow, as these flow systems interact with the rock framework and all other geofluids resulting in a systematic distribution of the related environmental and geological processes and phenomena. The presented methodological developments and mostly general results have been and can be utilized in the future in any sedimentary basins. These cover the following fields of hydrogeology and geofluid research: carbonate and karst hydrogeology, asymmetric basin and flow pattern, geothermal and petroleum hydrogeology, radioactivity of groundwater, groundwater and surface water interaction, groundwater-dependent ecosystems, effects of climate change on groundwater flow systems, managed aquifer recharge.</p></div>","PeriodicalId":36948,"journal":{"name":"Journal of Hydrology X","volume":"17 ","pages":"Article 100142"},"PeriodicalIF":4.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2589915522000244/pdfft?md5=7cb5db394ed2ca816b2aeb4f13dce39c&pid=1-s2.0-S2589915522000244-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45949428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interannual variability of ice cover in the Caspian Sea","authors":"Olga Yu. Lavrova ,&nbsp;Anna I. Ginzburg ,&nbsp;Andrey G. Kostianoy ,&nbsp;Tatiana Yu. Bocharova","doi":"10.1016/j.hydroa.2022.100145","DOIUrl":"10.1016/j.hydroa.2022.100145","url":null,"abstract":"<div><p>Satellite remote sensing data (SAR and Ocean Color), MERRA-2 reanalysis and records at Astrakhan meteorological station were used to investigate interannual variability of ice cover characteristics in the North Caspian Sea for 23 winter seasons (November 1 – April 15) from 1999/2000 to 2021/2022. The maximum annual ice cover area, ice freeze onset and melt dates and ice cover duration were determined from satellite remote sensing data, mostly SAR instruments on board the European Space Agency’s satellites, ranging from ERS-2 to the Sentinel-1A, -1B tandem. We propose a new band combination for Sentinel-2 MSI and Landsat-8 OLI that allows better distinguishing ice cover from clouds or land than the standard RGB composites. In the absence of SAR data, this method was used to estimate the above mentioned parameters with high spatial and temporal resolution. To assess the severity of winters, the criterion on the basis of the sum of freezing degree-days (SFDD) was applied. For this purpose, we used values of daily minimum air temperature over the North Caspian (44.46°–47.14°N, 46.70–52.90°E), daily mean and daily minimum ones over its coldest eastern part (with the western border at 50°E), obtained from the MERRA-2 reanalysis, as well as data from the meteorological station in Astrakhan (46.35°N, 48.07°E). The resulting SFDD sequences show that until the winter of 2011/2012, there was a cooling trend on average (with noticeable interannual variability), whereas after that winter it changed to warming for Astrakhan and virtually disappeared for the North Caspian and its eastern part. A noticeable interannual variability is also shown by the maximum ice area and the duration of the ice period, both parameters with maximums in the winter of 2011/2012. We discuss in detail the correspondence between the SFDD and ice cover characteristics variations, as well as previously published results. In agreement with the other authors, we find that in the 21st century, compared to the 20th century, the number of very severe and severe winters has decreased, while the number of mild winters has increased.</p></div>","PeriodicalId":36948,"journal":{"name":"Journal of Hydrology X","volume":"17 ","pages":"Article 100145"},"PeriodicalIF":4.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S258991552200027X/pdfft?md5=ed9ec05e24289cd15da5f741591d7f81&pid=1-s2.0-S258991552200027X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44552397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}