bluuebunny/crossref_metadata_2025 huggingface dataset:
GCM-Motivated Multidimensional Atmospheric Temperature Parameterization
Authors: Dobbs-Dixon Ian
Published: September 2022

We present a new GCM-motivated multidimensional temperature parameterization of hot-Jupiter atmospheres that self consistently models the entire planet in 3D, accounting for both radiative and advective phenomena. Analytic formulations for the radiative component of the energy budget are readily available but an analytic model for the advective component, characterized primarily by strong jets, has proven elusive. To address this, we utilize GCM models to decouple the two processes. Utilizing a subset of simulations with very large damping we effectively reproduce the analytic radiative solution, which can then be subtracted off the full results to isolate the advective component. We find this advective component is well modeled in pressure, latitude, and longitude by subdividing the atmosphere into longitudinal sections, with negative values on the dayside where the jet is removing energy, and positive values on the nightside where energy is deposited. The extent of this term in pressure defines the depth to which the jet penetrates into the atmosphere while the latitudinal extent defines the width. The framework is sufficiently flexible to recreate a wide variety of atmospheres, including oddballs like westward shifted offsets.
Characterising the internal structures of small exoplanets with CHEOPS
Authors: Wilson Thomas
Published: September 2022

The successful Kepler and TESS missions have discovered thousands of exoplanets and let the community focus on the characterisation of these bodies. One area of research utilises ultra-high-precision photometric and spectroscopic follow-up observations in order to accurately constrain the bulk densities of terrestrial exoplanets. Combining these observables with Bayesian internal structure modelling that uses geological equations of state, we can start to learn about the compositions of planets around main-sequence stars for the first time. Importantly, by studying multi-planet systems we can conduct comparative planetology that can reveal important aspects that challenge our knowledge of planet formation and evolution via the contrastment of the observational and modelling results of a planet against its neighbours.

In this talk, I will present observational studies characterising multi-planet systems initially discovered with TESS and followed-up with ultra-high precision photometry from the recently launched CHEOPS satellite and ground-based RV instruments, such as HARPS and HARPS-N. Additionally, I will discuss our Bayesian internal structure and atmospheric escape analyses, and present the results of utilising such models on several key, multi-planet systems observed with CHEOPS, such as TOI-1064 and TOI-561, that are expected to become cornerstones of exoplanet characterisation due to the questions they raise about planet formation, the system multiplicity, or the amenability to atmospheric observations. Important knowledge about these new systems was uncovered via the refined radii, masses, and densities, a combination of precise observations using a new generation of instruments across different techniques, and cutting-edge planetary internal structure modelling. Therefore, utilising these resources we are at the beginning of a new era in characterising terrestrial bodies outside of our Solar System that will be strengthened with JWST.
Lipidomics Based Microbial Ecology Snapshot of Ophiolitic Rocks
Authors: Zetterlind Alexandra , Rattray Jayne E. , Smittenberg Rienk H. , Potiszil Christian , ten Kate Inge Loes , Neubeck Anna
Published: September 2022

Energy from active serpentinization processes potentially fuelled the origin of life on Earth, thus, if serpentinite-impacted sites facilitate microbial habitability, it is important to understand the source and retention of biological signatures in serpentine rocks. Investigating biological signatures in terrestrial analogues of serpentinite-impacted environments is also essential for interpreting molecular signature preservation on extra-terrestrial bodies.

To expand knowledge on the types of biological signatures directly derived from living microorganisms (intact polar lipids, IPLs), and both living and dead microorganisms (core lipids), mass spectrometry analysis was performed on Chimaera serpentinite rocks from Antalya Province, Turkey. Brucite rocks were dominated by IPLs from fungal, eukaryotic origin but in contrast, travertine samples had IPL profiles consistent with a mixed fungal, archaeal and bacterial community. The abundance and diversity of archaeal IPLs was significantly higher in the travertine compared to the brucite, and the abundance of archaeal IPLs inside the travertine rock was highest. Archaeal specific core lipids identified inside the brucite rock were not observed as IPL counterparts, suggesting the presence of a non-viable or fossil archaeal community. Comparing IPL profiles with core lipids can discriminate between living microbial communities, necromass, and fossils to combine as a promising molecular tool for identification and interpretation of bio-signatures in serpentinite-impacted sites. Continuing survey of serpentinization samples on Earth can act as analogue environments and provide valuable insight into microbial habitability on Mars and other planetary objects.
Controlling or rewilding the river: local expressions of a tension between revitalization and risk control, case study of the Vistre plain 
Authors: Serrhini-Naji Ghita
Published: September 2022

The Vistre plain is subject to a hydraulic functioning specific to Mediterranean regimes, notably characterized by intense and short episodes of heavy rainfall, and rapid to torrential flooding kinetics. To guard against risks, the public management institutions of the drainage basin have gradually put in place a set of devices consisting of best practices, administrative tools, technical infrastructure, vigilance and flood forecasting services, crisis management plans and awareness programs. During the 2014 flood episode, these institutions agreed on the fact that many damages were limited thanks to the works built, since 2007, within the framework of flood prevention plans. However, it is important to question these devices in light of the challenge of requalification that this highly anthropized river presents. Indeed, the academic sphere as well as the operational sector have recently demonstrated a desire to go beyond the diametric opposition between anthropic and ecological interests to renew the questioning on socio-ecological interdependencies. This opposition is challenged, in particular, by the counter-productivity of certain measures aimed at protecting oneself from nature: the artificialization of the functioning of rivers can increase the risk of flooding.

These considerations are part of the objectives of the syndicate in charge of managing the Vistre. Since 2002, it has explicitly chosen a policy of revitalization (or renaturation) rather than restoration (or rehabilitation) of the Vistre. We hypothesize that this political choice contributes to the local emergence of a tension between protecting and being protected from nature. This poster will present the first results of a survey by semi-directive interviews and questionnaires conducted with stakeholders (inhabitants, associations and institutions), aiming to better understand the evolution of the perception of socio-ecological interdependencies at work around the revitalization projects in the Vistre Plain. This understanding, based on the collection of local representations and practices, will shed light on the conditions of conciliation between revitalization and flood protection policies.
Estimating water flows and water availability in a poorly monitored semiarid small dam using reverse water balance and remote sensing.
Authors: Estacio Alyson , Rocha Renan , Linhares Samiramisthais , Vieira Leticia , Alves Rafaela , Martins Eduardo
Published: September 2022

Small communities of the semi-arid region suffer not only with water scarcity but also with data scarcity. The lack of data to perform water management at the local level is a common problem faced in developing countries. The absence of monitoring of water levels of small reservoirs across Ceará State (Northeast Brazil) results in inefficiencies in local water management and in difficulties to fully comprehend the extension of the impact of these changes in the natural streamflow and in the water supply for the state’s network of strategic dams. Small reservoirs construction is the individual private strategy mostly performed to cope with the local droughts. Recent studies shows a strong expansion of this strategy in the recent years, with the construction of more than 100.000 small reservoirs just in one of the state basins. This aspect reveals the necessity of strategies to obtain reliable information about these small reservoirs to perform a comprehensive estimation of these reservoirs impacts in both the local and state level of water management. In this study, local drone images were obtained for a small reservoir in the Ceará State. Remote sensing was used to obtain the reservoir depth-area-volume relationship and reverse water balance technique was used to estimate the different water fluxes and assess the local water availability. The results shows the inefficiency of these small reservoirs due to high evaporation losses, reflecting its high vulnerability to droughts. The proposed methodological scheme proves to be powerful in generating hydrological information by the intricate use of data, besides being replicable for other reservoirs in arid and semiarid regions.
Remediation of Per- and Polyfluoroalkyl Substance (PFAS) Contaminated Soil with Colloidal Activated Carbon: Lessons Learned from a Swedish Case Study
Authors: Niarchos Georgios , Berggren Kleja Dan , Ahrens Lutz , Fagerlund Fritjof
Published: September 2022

 Per- and polyfluoroalkyl substances (PFAS) are fluorinated organic chemicals that have extensively been used for more than five decades worldwide, resulting in their ubiquitous spreading . In the light of their toxicity, recalcitrance and bioaccumulation potential, their use and disposal are increasingly being limited. Groundwater is one of the environmental pathways critical for PFAS dispersal and subsequent human exposure. Case studies on PFAS groundwater contamination are lacking and remediation efforts applied in full-scale are limited. In this context, the main objective of this study was to quantify the extent of PFAS contamination in the subsurface and evaluate the effectiveness of a trap-and-treat in-situ soil remediation method with the use of colloidal activated carbon. A PFAS-contaminated site was selected for investigation in Sweden, that has previously been used for fire-fighting training with PFAS-containing aqueous fire-fighting foam (AFFF).

 PFAS concentrations and hydrological properties of the contaminated site were investigated. Groundwater was sampled through five monitoring wells, while surface water samples were collected at four different locations in a stream adjacent to the site monthly-bimonthly. PFAS concentrations were quantified for 11 individual PFASs. Colloidal activated carbon was injected in the subsurface, aiming for a good distribution of the sorbents in the treatment zone. Monitoring wells were drilled upstream and downstream to the injection well, identifying variations in concentrations through time. Total oxidizable precursor concentrations were also quantified in two observation wells. Other parameters that were monitored in the wells included pH, conductivity and metals concentrations. Groundwater levels were measured by manual sounding as well as by automated logging with barometric compensation. Aquifer characteristics were defined by slug tests and the site’s geological characteristics were investigated.

Prior treatment, groundwater concentrations of ∑PFASs were up to 24 μg L-1, while two significant hotspots were identified. ∑PFASs concentrations decreased by ~74% based on the original concentration within and directly downstream of the treatment zone approximately three months after applying the colloidal activated carbon. Differences in the PFAS composition profile after injection, indicated a stronger reduction for PFOS in comparison to, for example, PFOA. However, long-term monitoring is needed to assess the treatment’s efficiency over time.
Isotope hydrology to insight the behaviour of Mediterranean Temporary Ponds: Implications on sustainable ecohydrological management strategies
Authors: Mattei Alexandra , Huneau Frédéric , Garel Emilie , Sorba Laurent , Santoni Sébastien , Orsini Sophie
Published: September 2022

Mediterranean temporary ponds are very shallow ponds, isolated from permanent water bodies, which undergo a periodic cycle of flooding and drought, and have a characteristic flora and fauna adapted to this alternation. They are identified as one of the worldwide biodiversity hotspots and constitutes therefore a priority habitats according to the Natura 2000 network of the European Union. Despite this protective conservation status, this habitat has suffered continuous degradation and loss, disappearing at a fast rate due anthropogenic impacts and climate pressures. In most cases, temporary wetland disappearance is unintentional and related to a lack of understanding of its hydrological functioning within the watershed.

In this study, we use observations of hydraulic heads, geochemical and isotopic composition of pond and groundwater from the Musella pilote study site (Corsica, Western Mediterranean) to assess the applicability of the isotope hydrology tools for understanding the hydrological behaviour of temporary wetlands and refine their optimal environmental conditions.

By combining together physical and isotope measurements, we demonstrated (i) the main role played by groundwater and subsurface water in the flooding phase of the temporary pond; (ii) the involvement of different water reservoirs in varying proportions over time to maintain the pond filled with water: precipitation, subsurface and groundwater by using d-excess; (iii) the main role played by evaporation in the starting of the drying up phase; and (iv) the connection existing between a geographically isolated wetland and the regional groundwater body.

Results bring the urgent need to consider both surface and groundwater fluxes in wetland’s specific protection statutes. To this aim, we encourage the use of the water stable isotopes to insight the hydrological behaviour of the wetlands in order to have additional cost-effective arbitration elements able to help ensuring their sustainability considering the future consequences of climate change in the Mediterranean region.
Impact of water withdrawals and releases on the parameters of a bucket-type rainfall-runoff model
Authors: Santos Léonard , Thirel Guillaume , Perrin Charles
Published: September 2022

Water management practices (dam management, uptakes for irrigation, industry and domestic water supply or water sanitation) can strongly influence river flow at the catchment scale. If water withdrawals and releases are important (for example in the case of a large dam), this influence can strongly impact the performance of bucket-type rainfall-runoff models whose structure do not explicitly consider water management practices. However, the influence of water management can also be compensated by the calibration of parameters, which is difficult to perceive when the model is conceptual, as the performance may not necessarily be negatively affected. This work aims at evaluating the effect of these compensations over the parameters of the GR4J bucket-type rainfall-runoff model over an influenced catchment. To do so, the model was applied in a semi-distributed way over the rainfed Sèvre Nantaise catchment in Western France. For this catchment, we used uptakes, sanitation and reservoir management data estimated at a daily time step, as well as a dense network of daily flow measurement stations. Water management practices were explicitly taken into account in the GR4J model through the airGR and airGRiwrm R packages that allow injecting or removing water from the river depending on water management practices. The model was calibrated on the different flow stations both with and without taking water withdrawals and releases into account. The obtained parameter values were compared in terms of reliability, robustness, plausibility and spatial homogeneity.
Decadal variability in long- and short-lived hydrological extremes in Sub-Saharan Africa
Authors: Ekolu Job , Dieppois Bastien , Eden Jonathan , Tramblay Yves , Villarini Gabrielle , Mahé Gil , Paturel Jean-Emmanuel , van de Wiel Marco
Published: September 2022

Sub-Saharan Africa is affected by a high-level of temporal and spatial variability in climate, with large impacts on water resources, human lives and economies, notably through hydrological extremes, such as floods and droughts. Using a newly reconstructed 65-year daily streamflow dataset of over 600 stations distributed throughout sub-Saharan Africa, we first highlight that the frequency, intensity and duration of hydrological extremes are strongly impacted by decadal to multi-decadal variations. However, the key factors driving such decadal to multi-decadal variability remain poorly documented and understood. Thus, here, compiling information on local-scale drivers (precipitation, temperature, soil moisture) and large-scale drivers (sea-surface temperature modes of variability, such ENSO and AMO, in the different ocean basins), using relative importance analysis and multiple datasets (ERSSTv3, ERA5-land, REGEN), we investigate the respective contribution of large-scale versus regional-scale processes in driving decadal to multi-decadal variability in long-lived and short-lived flood and drought.
Data assimilation of global hydrological model discharge to constrain a distributed hydrological model
Authors: Devers Alexandre , Lauvernet Claire , Vidal Jean-Philippe
Published: September 2022

Daily climate projections have been recently created using several global climate models under different scenario emissions for their specific use as inputs for global hydrological models (Lange et Büchner., 2021). Despite the interest of these data, their coarse resolution prevent them to be used for hydrological models at the catchment scale and even more at the reach-scale.

This work therefore proposes a novel approach to make use of both global climate and global hydrology information and derive catchement-scale hydrological time series through a distributed hydrological model and a specifically designed data assimilation method. The final objective is to produce future streamflow series over 6 catchment case studies in Europe as part the DRYvER project (Datry et al., 2021). To that end, coarse climate forcings are downscaled through a spatial analogue procedure on precipitation, temperature, and potential evapotranspiration to derive ensemble time series of meteorological forcings. This ensemble then serves as an input to the distributed hydrological JAMS-J2K model (Krause et al., 2006). Finally, the hydrological distributed model JAMS-J2K is constrained by global hydrological time series available at the catchment outlet using a Particle Filter data assimilation procedure (van Leeuwen, 2009).

This setup is first applied to DRYvER catchments during the historical period 1995-2015, securing independent observations over the catchments to evaluate the impact of data assimilation. These experiments put forward the improvement of high-resolution hydrological simulations resulting from the assimilation of discharge from a global hydrological model, with respect to a simulation only driven by coarse meterological time series. Furthermore, by construction, the method allows deriving daily high-resolution hydrological time series coherent with global hydrological time series, paving the way for reach-scale hydrological projections under climate change scenarios.

 

Datry et al. (2021) Securing Biodiversity, Functional Integrity, and Ecosystem Services in Drying River Networks (DRYvER). Research Ideas and Outcomes. In press.

Krause et al. (2006) Multiscale investigations in a mesoscale catchment: hydrological modelling in the Gera catchment. Advances in Geosciences. doi:10.5194/adgeo-9-53-2006.

van Leeuwen (2009) Particle Filtering in Geophysical Systems. Monthly Weather Review. doi:10.1175/2009MWR2835.1.

Lange et Büchner (2021) ISIMIP3b bias-adjusted atmospheric climate input data (v1.1). ISIMIP Repository. doi:10.48364/ISIMIP.842396.1.
 A stakeholder-driven process to develop a sustainable water resources management plan in the Koue Bokkeveld farming region, Western Cape-South Africa
Authors: Gwapedza David , Mantel Sukhmani , Bonte Bruno , Theron Stefan , Mabohlo Sakikhaya , Xoxo Sinethemba , Paxton Bruce , Barreteau Olivier , Tanner Jane
Published: September 2022

Abstract

Background/aims

Water scarcity is a significant problem in South Africa. Low average rainfall results in limited water available for human and environmental needs. Consequently, competition for water resources is increasing and has resulted in water-related conflicts among the various water users in many areas of South Africa. Unfortunately, when competition for water use exists, Environmental Water Requirements (EWRs) are often ignored, thus impacting the health of riverine ecosystems and downstream ecosystem services. Such a situation characterises the Koue Bokkeveld farming region. Conflicts are rife between upstream farmers who have initial access to river water and downstream farmers forced to use what remains after upstream users satisfy their needs. The situation entrenches inequality and fuels conflict and, if left unmanaged, may lead to a breakdown in the farming community. The resultant loss in agricultural productivity will affect food security and the livelihood of the thousands of farmworkers who work in the area. This research project responds to this problem by negotiating a shared water management strategy that achieves equity in water access and respects EWR.  The broader aim is to assist Koue Bokkeveld (KBV) stakeholders in co-developing a water resources management strategy that results from a shared understanding.

Methodological framework

To achieve the research aim, a mixed methodological approach driven by Agent-Based Modelling is employed. A companion modelling approach is adopted, thus placing stakeholders at the centre of the model development and application. A series of stakeholder workshops are lined where stakeholders will provide input into and validate the model. Future scenarios (and subsequent impacts on an agreed water management plan) will be evaluated, assisted by hydrological modelling of future flows.

Preliminary results

 An initial conceptual ABM model based on literature and an understanding of the study area representing the key actors, resources and dynamics obtained in the catchment has been developed. An initial stakeholder workshop to solicit stakeholder buy-in has been conducted with success. Although stakeholders remain sceptical about their identities and activities being kept in confidence-they are keen to participate in the following workshops.

Keywords: ABM, South Africa, stakeholder-engagement, water resources, modelling
The OZCAR Critical Zone Observatory Network: an opportunity to address some unsolved problems in hydrology
Authors: Braud Isabelle , Gaillardet Jérôme
Published: September 2022

The OZCAR (Critical Zone Observatories network) Research Infrastructure (RI) brings together a group of observatories in the critical zone, the thin pellicle on the Earth's surface between the unweathered rocks and the lower atmosphere, which is the living environment of living beings. These long-term observatories were historically created in France to answer specific scientific questions such as the impact of rainfall acidification on forests, the genesis of extreme floods and the understanding of nitrate pollution. They document different compartments of the critical zone (atmosphere, soil, surface water, groundwater, cryosphere, wetlands, biosphere, etc.) through the measurement of a large number of meteorological, hydrological, hydrogeological, geochemical, surface fluxes and vegetation dynamics variables. The aim of OZCAR RI is to foster data sharing between these observatories through a common data portal, to promote the use of the collected data through the synergy between data and models, to allow the development and deployment of new measurement techniques, and to favor interdisciplinary researches. These observatories, and their counterparts at the European scale gathered in eLTER RI, provide highly instrumented sites and platforms that can provide data and experimental sites for addressing some of the 23 unsolved problems in hydrology. The presentation will illustrate this through examples of researches conducted in the OZCAR RI network.

https://www.ozcar-ri.org/fr/ozcar-observatoires-de-la-zone-critique-applications-et-recherche/
Recharge and groundwater dynamics in the Tamanrasset alluvial aquifer (Algerian Sahara)
Authors: Hadj Saïd Samia , Zeddouri Aziez , Taupin Jean Denis , Patris Nicolas , Leduc Christian
Published: September 2022

            Social, economic and environmental changes are deeply affecting the entire Earth. Population growth and agricultural intensification are ever more demanding in natural resources, and especially water that is now threatened in both quality and quantity. This degradation is particularly visible in semi-arid and arid areas. The Sahara desert is typical of these multiple constraints and rapid changes where the sustainable management of water resources is a major issue. In Southern Algeria (P < 80 mm.a-1, PET > 2000 mm.a-1), perennial water reserves are groundwater with a small to very small recharge: the biggest regional aquifers are considered as having nearly fossil water. In contrast, the alluvial areas associated with the currently active wadis represent small aquifers which are renewed by a few floods each year. In the case of Wadi Tamanrasset, the alluvial aquifer has an average thickness of 20 m and is exploited by the inhabitants because of its accessibility and its good chemical quality. Rare recharging flood events occur mainly between July and September.

            We studied the physical conditions commanding flow and recharge of groundwater, and especially the transfer from surface to groundwater by combining hydrodynamics and isotope tracing of water (18O, 2H). Monthly monitoring of groundwater level was carried out in around thirty wells and was complemented by automatic recorders with hourly time steps installed since March 2016 in three wells, along a 600 m transect perpendicular to the wadi bed. The part of flood water recharging the alluvial aquifer could then be estimated. The response of the water table is slow and continuous, and becomes visible only two months after the first flood; its maximum rise was 1 m in 2016. Isotopic analyses of rain water on a daily time scale, of the wadi water on a 1-hour time scale during runoff and of groundwater (two complete campaigns in the dry and wet seasons and a specific monitoring of the transect every month) have provided additional information on surface-groundwater transfer.

 
Use of spatial data for water resources monitoring
Authors: Rocquelain Gilles , Legay Thomas , Aubert Yoann
Published: September 2022

The management of water resources requires the use of hydrometric data mainly from in situ stations. Despite the efforts made in setting up and maintaining a network of stations (hydrometric or meteorological), water resource managers face many problems (degradation of equipment during floods, vandalism, inaccessibility, etc. …) Satellite data can enrich the monitoring of water resources, whatever the objectives of this monitoring (strategic management of water resources, management of structures, forecasting of floods and low flows, etc.). These data have the advantage of covering the entire world at regular intervals, including difficult-to-access areas. Through several projects, various scientific and industrial partners (IRD, CNES, CLS, CNRS, CENEAU, etc.) have contributed to assess and enhance the use of satellite data for the management of water resources at the scale of a watershed (eg the Amazon) or a territory (Uganda). The objective is to deliver hydrological indicators resulting from the combination of hydrological models, in-situ data and satellite data. This article presents the current possibilities and limitations of using satellite data to optimize the monitoring of water resources. KEYWORDS: Coupling, satellite data, hydrological modeling, inter-comparison.
Veterinary pharmaceutical and fecal contamination in mixed-land use watersheds: from agricultural headwater watersheds to water-monitoring watersheds. 
Authors: Jaffrezic Anne , Charuaud Lise , Liotaud Marine , Mercier Fabien , Le Bot Barbara , Jardé Emilie
Published: September 2022

Veterinary pharmaceuticals, widely used in intensive livestock production, may contaminate surface waters. Identifying their sources and pathways in watersheds is difficult because i) most veterinary pharmaceuticals are used in human medicine as well and ii) septic or sewer wastewater treatment plants (WWTP) can release pharmaceuticals into surface water, even in agricultural headwater watersheds. This study aimed to analyze the spatiotemporal variability of animal-specific, mixed-use, and human-specific pharmaceuticals, from agricultural headwaters with intensive livestock production and a WWTP to a watershed used for Water Framework Directive monitoring. Grab sampling was performed during three hydrological year in seven nested watersheds in intensive husbandry area upstream and downstream from a WWTP with areas of 1.9-84.1 km². Twenty pharmaceuticals were analyzed. Microbial fecal indicator E. coli and fecal stanols were determined. Fecal stanols are microbial source tracking tool allowing to identify the origin of the fecal contamination (porcine, bovine or human). Animal-specific pharmaceuticals were detected at all sampling dates upstream and downstream from the WWTP and at concentrations higher than those of human-specific pharmaceuticals. Animal-specific pharmaceuticals were detected mainly during runoff events associated with bovine or porcine fecal contamination. A large percentage of mixed-use pharmaceuticals was assigned to animal sources. Mixed-use and human-specific pharmaceuticals predominated in the largest watersheds when runoff decreased. In areas of intensive livestock production, mitigation actions should focus on agricultural headwater watersheds to decrease the number of pathways and the transfer volume of veterinary pharmaceuticals, which can be the main contaminants.
The value of synthetic high-resolution daily snow cover maps for long-term hydrological modeling
Authors: Wiersma Pau , Zakeri Fatemeh , Mariéthoz Grégoire
Published: September 2022

To study long-term changes in the hydrology of snow-fed catchments, there is a need for long-term time series of snow cover data. Satellite imagery and climate reanalysis can both be used to quantify past snow cover, but they lack in baseline period length and spatial resolution respectively. In this study we apply statistical methods to generate synthetic high-resolution daily snow cover maps, and consequently use these maps as forcing in long-term hydrological modeling. The results are benchmarked against a case without synthetic snow cover forcing. Multiple hydrological models are used to reduce the uncertainty related to the model choice. The study is performed on the Thur catchment in Eastern Switzerland, a meso-scale catchment covering a wide elevation range and experiencing multiple periods of intermittent snow cover annually. We expect the synthetic snow cover maps to provide added value through the high-resolution spatial information on snow appearance and disappearance, leading to better estimates of snow melt runoff. However, we also expect them to show some physical inconsistencies, particularly after periods of high snow accumulation. Should it prove promising, this approach can be used to study both past and future hydrological changes in any snow-fed catchment using ERA5 and CMIP6 climate data, potentially spanning the entire period 1950-2100. Additionally, this framework of synthetic satellite data generation could be expanded to other hydrological variables or to environmental image time series in other fields than hydrology.
Petrophysical characterization of a clastic coastal aquifer with implications for saltwater intrusion and the evolution of groundwater resources. The DEM'EAUX ROUSSILLON project, Occitanie, France.  
Authors: Pezard Philippe , Lofi Johanna , LeBer Erwan , Henry Gilles , Brun Laurent , Geeraert Muriel , Hamel Colin , Gee Ryan , Brillouet Nicolas , Neyens Denis , Caballero Yvan
Published: September 2022

More than 80 Mm3per year are pumped into the Roussillon plain coastal aquifer located between the Pyrenean massif to the South and West, and the Mediterranean to the East. This is a 350 m thick Pliocene multilayered aquifer, with sandy layers embedded in low-permeability clayey material and topped by Quaternary alluvial deposits. The groundwater resource is primarily used for drinking water and irrigation. For more than 40 years, this aquifer has been undergoing a piezometric level decline due to pumping, while water demand is expected to increase with ongoing climate change, sea level rise and increasing demand in water use. Consequently, the Roussillon aquifer is likely to suffer from sea water intrusion and marine submersion in the near future.

As part of the Dem'Eaux Roussillon project, a set of downhole geophysical profiles was recorded at three drill sites, in Saint Cyprien and Barcares along the Mediterranean shore and at Pollestres, 14 km inland. Downhole petrophysical data (NMR porosity and permeability, acoustic velocities, electrical resistivity and spectral gamma natural radioactivity) contribute to better define the penetrated structure. Core petrophysical measurements were also made to support and calibrate these analyses and, in particular, to provide a dm-scale description of the subsurface pore fluid electrical conductivity along the length of each hole. A combined analysis of the latter with porosity and permeability points at incipient and m-scale intrusion processes along discreate horizons.

Repeated downhole measurements overtime and fluid sampling provide a means to follow the dynamics of these intrusion processes found to be more acute at the Barcarès site to the North than close to the Pyrenean, at Saint Cyprien. While high-resolution permanent downhole geophysical observatories have been installed to measure at high frequency both formation electrical resistivity and temperature, a real time management of groundwater resources should contribute to improve aquifer water quality in the future. These observatories datasets will be analyzed and modeled on the basis of smaller scale petrophysical data, providing both an assessment of water quality evolution in terms of salinity from resistivity and quantity in terms of flow rate from temperature.
Identification of some water quality parameters of the liquid effluents discharged from recent urbanization
Authors: Bougherira Nabil , Hani Azzedine , Chaffai Hicham , Vanclooster Marnik , Djabri Larbi , Nechem Dounia , Saadali Badreddine , Boubelli Salim , Nahal Ahmed
Published: September 2022

Algeria has established a growing urban pole, therefore urbanization and urban dynamics are increasing from year to another, and it occurs a flow of excessive urban wastewater discharges from these agglomerations.

In this research, we are interested in the evaluation of the current state of wastewater, which comes from 1114 residences by household activities and human metabolism, or the mixing of domestic wastewater with water runoff.

In the extreme North east of Algeria, the predominantly domestic waters of Drâa-Errich city, evacuated through collectors and without treatment they are rejected in nature, and the quality of the water at the level of the Gueridjima wadi has deteriorated and these waters currently constitute a polluted effluent which joins the waters of the El Aneb wadi to the west. 

A set of analyzes was carried out (period of April to May 2021) on domestic wastewater to assess their quality.

Sampling and analysis carried out of surface water (02 samples from Gueridjima wadi and 02 samples from El Aneb wadi) and groundwater (01 well), covering an area of 15 km.

The physic-chemical parameters measured with the WTW multiparameter are pH, temperature, electrical conductivity EC, biological demand in oxygen BOD5. In addition, the undesirable substances are Nitrates (NO3-), Nitrites (NO2-), Phosphates (PO4-), and orthophosphate.

In front of this situation, the measures proposed are the systems for treating domestic wastewater sewage, seen the advantages represented by the topography of the land in the region; remains the better solution for possible reuse recovery of wastewater, in agriculture sector. This measure will certainly improve the quality in terms of production of an acceptable quality of (purified) wastewater, and reduce environmental problems

Keywords: current state - domestic wastewater - sewage - admissible quality.
Does a convection-permitting climate model improve the simulation of flash floods ? A case study over a Mediterranean watershed
Authors: Poncet Nils , Lucas-Picher Philippe , Tramblay Yves , Thirel Guillaume
Published: September 2022

Extreme rainfall and associated river floodings are important concerns in modern human societies. Despite a recent increase of extreme rainfall, there is no evidence of an increase of the intensity and frequency of flash floods in Southern Europe, and future projections of flash-floods are quite uncertain in part due to the coarse resolution of available climate model simulations.The recent development of convection-permitting climate models allow a better representation of precipitation extremes. This new generation of climate models have been little employed in combination with hydrological models up to now, and their added value for flash flood modeling remains to be identified.
In this work, a 2.5-km convection-permitting climate model (CNRM-AROME) simulation is used to force two hydrological models (CREST and GR5H). This new modeling chain is tested in a French mediterranean catchment, the Gardon at Anduze, that experienced severe flash flooding episodes over the last decades. Hydrological models are calibrated using the COMEPHORE 1 km observed precipitation dataset merging radar and rain gauge rainfall at the hourly time step. We compare the CNRM-AROME-based hydrological simulation to a benchmark run driven by a conventional CORDEX 12-km CNRM-ALADIN simulation. The analysis of the peak discharges simulated by both hydrological models driven by the different meteorological inputs allows to determine how higher resolution precipitation could improve the simulation of flash floods. 
Open Hydrology Principles and Practical Guide to Promote Diverse and Inclusive Research 
Authors: Hall Caitlyn , Dogulu Nilay , Saia Sheila , Popp Andrea , Schymanski Stanislaus , Drost Niels , van Emmerik Tim , Hut Rolf
Published: September 2022

Open science is high on the agenda of academic, national, and intergovernmental organizations because of its commitment to transparency and reproducibility. Transparent and inclusive research practices facilitate reproducibility and collaboration while improving research accessibility, attribution, governance, and community-driven support for marginalized researchers and stakeholders not usually included or credited in research. Hydrology is an inter- and multi-disciplinary science that integrates qualitative and quantitative data (field, lab, models, etc.) to address human life and natural ecosystems issues. Research progress in hydrology depends on accessibility of research output, like data, code, and publications. This necessitates openness – documentation and sharing of one’s research process, including definitions, motivations, justifications and assumptions, practices, and methods.

One fundamental step toward a more inclusive and diverse research community is to create equal access to knowledge for all hydrologists across the globe. Open science can facilitate equitable advancement and innovation to solve challenges and work towards the United Nations Sustainable Development Goals. To address barriers to starting or advancing one’s open science practices, we introduced the Open Hydrology Principles (Hall et al., 2021, HESS) and practical guide for hydrology researchers. We discuss the benefits and share tips to engaging in open science by focusing on four principal themes related to (1) Open Research Process and Approach, (2) Open Data, (3) Open Software Development and Use, and (4) Open Publishing. We hope that this guide enriched with practical advice (tips, tools, and resources) will help strengthen inclusivity and diversity in hydrology and globally inspire more hydrologists to pursue open science. We encourage everyone to contribute to the community-supported repository of open hydrology resources at https://open-hydrology.github.io/.   
Hydrological and agricultural impacts of small reservoirs: a numerical exploration based on a catchment in south-west France
Authors: Lebon Nicolas , Dagès Cécile , Leenhardt Delphine , Molénat Jérôme
Published: September 2022

Small reservoirs are dams built to intercept and store runoff water, thus providing water in agricultural areas for crop irrigation. Small reservoirs are presented by some stakeholders as a relevant strategy for adapting agriculture to climate change in regions with irregular rainfall over the year. However, the reservoir network can have a significant cumulative hydrologic impact, particularly on stream flow, which in turn can affect other water uses and the quality of downstream aquatic environments.

Here we present a numerical exploration of the impact of small reservoirs on hydrology and crop production in an agricultural catchment. The modelling is based on Mhydas-Small-Reservoirs, a model coupling hydrology, crops and farmers' water management decisions. A 20 km² catchment area in south-west France is used as a case study.

Several catchment situations were considered. These situations combine different levels of reservoir use (current situation with 26 reservoirs of which only 13 are exploited to irrigate crops, a situation with no reservoirs at all, a situation where reservoirs currently not exploited are used for irrigation) and different climatic years (dry, wet and average rainfall year).

The simulations were analysed with respect to crop yields and different water balance terms (stream flow, ET, irrigation abstraction). The simulations showed that the reservoirs decreased the annual stream flow. However, the direction (reduction or increase) and intensity of the impact on stream flow varied over time from month to month and also spatially along the stream network. The impact on crop yields was variable from crop to crop. Overall, the results show that the impact of small reservoirs on crop yields depends partly on the capacity of the small reservoir to intercept and store water.

These are exploratory results. The main conclusion drawn is that the Mhydas-Small-Reservoirs model has the capacity to estimate in time and space the impact of small reservoirs on the agricultural and hydrological functions of agricultural catchments.
Role of the riparian groundwater in a pristine Mediterranean micro-estuary catchment to quantify nutrient fluxes
Authors: Garel Emilie , Dufresne Christiane , Santoni Sebastien , Huneau Frederic , Malet Nathalie
Published: September 2022

Catchment fluxes are the main vector of nutrients to marine ecosystems. Most of the time research focuses on regional catchments and their nutrient contribution toward estuaries, deltas or lagoons. Fluxes coming from coastal watersheds with smaller size are under-investigated, especially micro-estuaries, in spite of their predominance in many coastal areas and particularly in the Mediterranean.

The catchment-micro-estuary continuum has a strong seasonal variation dynamic controlled by transversal water and nutrients fluxes through the watershed, estuary and coastal zone.

Identifying and quantifying the water, inorganic and organic fluxes is unavoidable to understand the hydro-ecological behaviour of the micro-estuaries. For this purpose, the Fiume Santu watershed located on the Mediterranean Island of Corsica (France) has been investigated with a hydro-ecological approach based on the crossing-use of isotopic, chemical and nutrient tracers.

The study was carried out in a humid period in February 2018 and investigations involved a multi-tracer methodology, namely major ions and traces elements, stable isotopes of water, carbon isotope ratios and concentrations of DIC as well as measurements of DIM and DOM. Eight sampling sites were chosen along the estuary from top to bottom: four along the river, three for groundwater and one in open-sea water.

Results highlight hydrological processes in the down part of the catchment which are constrained by the tidal phenomena stopping temporarily the freshwater and nutrient circulation. The catchment fluxes, the chemical and biological intrinsic processes (remineralization, sediment uptake and release) and the marsh inputs constitute sources of nutrients along the stream and induce non-conservative budgets. The role of groundwater and subsurface water is significant in terms of nutrient fluxes even their discharge contribution is neglected.

This first mutual tracer-approach in the hydrological functioning and the ecological behaviour is unique in terms of the quantification of nutrient fluxes in a pristine coastal site and is the first step toward a transposition of the methodology to other Mediterranean sites.
Methodologies for the study of change in hydrology and society
Authors: Pande Saket , Scolobig Anna , Adamowski Jan , Ajami Newsha , Carr Gemma , Catellatti Andrea , Du Erhu , Guillaume Joseph , Haeffner Melissa , Kreuger Tobias , Perez-Blanco C. Dionisio , Roy Tirthankar
Published: September 2022

This paper reports on the progress being made on the “Methodologies” chapter of the Panta Rhei synthesis book due in May 2023 and to be officially launched at 2023 IUGG General Assembly in Berlin. Panta Rhei cornerstone emphasis is to support policies and decision making through better understanding of phenomena that emerge from social and hydrological processes of human water relations and anticipate their future evolution. Different disciplines have different societal objectives or similar objectives with different lens within the domain of Panta Rhei. As a result different are methods used, with their respective challenges. Taking stock of extensive research conducted in the past decade in context Panta Rhei, this chapter identifies a spectrum of methods that have been used to understand and interpret human water relations, with qualitative methods at one end and quantitative methods at the other end of the spectrum. The chapter then synthesizes the methods by proposing that a phenomenon has more than one color in the qualitative-quantitative spectrum when viewed through the prism of interpretation. Taking a couple of examples of phenomena, such as Jevon's paradox, the chapter demonstrates how various methodological colors in the spectrum (qualitative methods such as focus group discussions, surveys and quantitative methods such as agent based models) are needed to interpret its emergence, e.g. as a result of a lack of disincentives in case of Jevons paradox. It is concluded that for the first time diverse disciplines are converging in their pursuit of understanding and predicting human water systems for social good and Panta Rhei has accelerated this convergence. This chapter ends with a call to action on what further methodological developments appear promising and what methods should be more widely adopted, i.e. a celebration of what has been accomplished so far.