Hydrology modelling R packages: a unified analysis of models and practicalities from a user perspective

Following the rise of R as a scientific programming language, the increasing requirement for more transferable research, and the growth of data availability in hydrology, R packages containing hydrological models are becoming more and more available to hydrologists. Corresponding to the core of the hydrological studies workflow, their value is increasingly meaningful regarding the reliability of methods and results. Despite package and model distinctiveness, no study has ever 5 provided a comparison of R packages for conceptual rainfall-runoff modelling from a user perspective, contrasting their philosophy, model characteristics and ease of use. We have selected eight packages based on our ability to consistently run their models on simple hydrology modelling examples. We have uniformly analysed the exact structure of seven of the hydrological models integrated in these R packages in terms of conceptual storages and fluxes, spatial discretisation, data requirements and output provided. The analysis showed that very different modelling choices are associated with these packages, which emphasises various hydrological concepts. These specificities are not always sufficiently well explained by the package documentation. Therefore a synthesis of the package functionalities was performed from a user perspective. This synthesis helps inform selection of what packages could/should be used depending on the problem at hand. In this regard, technical features, documentation, R implementations and computational times were investigated. Moreover, by providing a framework for package comparison, this study is a step forward towards supporting more transferable and reusable methods and results for hydrological modelling in R

On the visual detection of non-natural records in streamflow time series: challenges and impacts

Large datasets of long-term streamflow measurements are widely used to infer and model hydrological processes. However, streamflow measurements may suffer from what users can consider anomalies, i.e. non-natural records that may be erroneous streamflow values or anthropogenic influences that can lead to misinterpretation of actual hydrological processes. Since identifying anomalies is time consuming for humans, no study has investigated their proportion, temporal distribution, and influence on hydrological indicators over large datasets. This study summarizes the results of a large visual inspection campaign of 674 streamflow time series in France made by 43 evaluators, who were asked to identify anomalies falling under five categories, namely, linear interpolation, drops, noise, point anomalies, and other. We examined the evaluators' individual behaviour in terms of severity and agreement with other evaluators, as well as the temporal distributions of the anomalies and their influence on commonly used hydrological indicators. We found that inter-evaluator agreement was surprisingly low, with an average of 12 % of overlapping periods reported as anomalies. These anomalies were mostly identified as linear interpolation and noise, and they were more frequently reported during the low-flow periods in summer. The impact of cleaning data from the identified anomaly values was higher on low-flow indicators than on high-flow indicators, with change rates lower than 5 % most of the time. We conclude that the identification of anomalies in streamflow time series is highly dependent on the aims and skills of each evaluator, which raises questions about the best practices to adopt for data cleaning.</p

RIO, septembre 1968. Bœufs (Les), hameau de la commune de Bains (Haute -Loire) RIO, décembre 1968. Pissebœuf (Thiers). Lettre de l'Abbé J. Delaigue

Delaigue J. RIO, septembre 1968. Bœufs (Les), hameau de la commune de Bains (Haute -Loire) RIO, décembre 1968. Pissebœuf (Thiers). Lettre de l'Abbé J. Delaigue. In: Revue Internationale d'Onomastique, 23e année N°2, avril 1971. pp. 144-145

Comparaison de la contamination des eaux par les métaux mesurée par gradient diffusif en couche mince (DGT), biosurveillance et concentration totale de métaux dissous à l'échelle nationale

International audienceIn this study, we propose to compare the metal contamination in water assessed by three monitoring tools: diffusive gradient in thin film (DGT), caged gammarids and grab samples of the dissolved phase. The study was conducted at a national scale on 101 sites throughout France and involved the deployment of DGT and gammarids at the same time. Cd, Cr, Co, Cu, Mn, Ni, Pb and Zn were measured in DGT, dissolved phase and gammarids. The data set was analyzed with an exploratory data analysis method: multiple factor analysis (MFA), which aims at comparing data sets structured in groups of variables in order to compare the groups and the conclusions to be drawn from the analysis of the data set by each group. No differences were observed for Co and Ni for the three methods. The gammarid group gave the richest information on the contamination of the sites because it discriminated the sites contaminated by Pb and Cd. Depending on the metals, DGT provided more information than grab samples, but less than gammarids. We conclude that the three monitoring tools gave complementary information on metal contamination, and their effectiveness in assessing metal contamination in water depends on the metal and the fraction studied

A dedicated polarimeter for the MuSiCoS échelle spectrograph

We present in this paper the technical characteristics of a new polarimetric unit dedicated to the MuSiCoS échelle spectrograph. The first test runs indicate that our instrument is very good at measuring polarisation or depolarisation structures in line profiles. It is therefore one of the very few facilities worldwide for studying magnetic topologies of active and chemically peculiar stars through rotational modulation of linearly and circularly polarised Zeeman signatures in line profiles. It is also a very interesting tool for investigating geometries of non-axisymmetric circumstellar environments through depolarisation of spectral lines formed within the scattering envelope

Calixarene complexes of anion-bridged oligouranyl species

The syntheses and structures of uranyl complexes of p-t-Bu-calix[6]arene (calix[6]H6) and p-t-Bu-calix[9]arene(calix[9]H9) are reported, further developing the role of calixarenes as 'cluster keepers'. The calix[6]arene com-plex, formulated as [(HO){UO2(calix[6]H4)(dmso)}3H], is trinuclear and linked symmetrically by the hydroxyl O atom. The calix[9]arene complex is binuclear, with a carbonate atom bridging between the two uranyl cations to give the complex, (HNEt3)3[(OCO2)(UO2)3(calix[9]H4)]

Validation des données haute fréquence sur l'observatoire ORACLE. Réseau des bassins versants

International audienc