Perceptual modelling of environmental Indicators to assess land uses impacts on water quality

International audienceStreams’ functioning is closely influenced by land uses along the stream itself and throughout the catchment. Land uses could both translate the natural environment or results of increasing human activities. These different land uses generate various (positive or negative) pressures depending on kind and intensity that alter river water quality for different scales of time and space. The objective of this research, applied on the Saône River (France) is to conceptualize and quantify the interactions between river water quality and land use through spatial modelling. Our methodology is based on (i) the design of indicators’ system using the DPSIR framework (EEA) (ii) the development of relevant environmental indicators able to characterize spatio-temporal evolution of the water quality, land uses and their interactions. The conceptual framework DPSIR helps to understand the global nature and the complexity of the problem; however it constrains the selection and development of environmental indicators. Water quality state is characterized by a bioindicator based on the abundance and the sensitivity of benthic invertebrates that are able to integrate different kinds of pressures at different time scales. The identification of the pressure indicators has been done thanks a literature review. They were built according to the nature of the land use, distance to rivers and location in the watershed. The indicators’ construction has been limited by the representativeness and homogeneity of data gathered from national databases. These data were supplemented by a work of very high spatial resolution land use mapping and by the results of a spatio-temporal change detection analysis

Integrated hydrological modelling of a managed coastal Mediterranean wetland (Rhone delta, France): initial calibration

This paper presents a model of a heavily managed coastal Mediterranean wetland. The hydrosystem studied , called ``Ile de Camargue', is the central part of the Rhone river delta. It comprises flat agricultural drainage basins, marshes, and shallow brackish lagoons whose connection to the sea is managed. This hydrosystem is subject to strong natural hydrological variability due to the combination of a Mediterranean climate and the artificial hydrological regime imposed by flooded rice cultivation. To quantify the hydrological balance at different spatial and temporal scales, a simplified model is developed — including the basin and the lagoons — using a time step that enables the temporal dynamic to be reproduced that is adapted to data availability. This modelling task takes into account the functioning of the natural and anthropogenic components of the hydrosystem. A conceptual approach is used for modelling drainage from the catchment, using a GIS to estimate water input for rice irrigation. The lagoon system is modelled using a two-dimensional finite element hydrodynamic model. Simulated results from the hydrodynamic model run under various hydro-climatic forcing conditions (water level, wind speed and direction, sea connection) are used to calculate hydraulic exchanges between lagoon sub units considered as boxes. Finally, the HIC ('Hydrologie de l’Ile de Camargue') conceptual model is applied to simulate the water inputs and exchanges between the different units, together with the salt balance in the hydrosystem during a calibration period.</p> <p style='line-height: 20px;'><b>Keywords: </b>water management,conceptual hydrological model, hydrodynamic model, box model, GIS, Rhone delta, Camargue

Evaluation de l’influence de l’occupation du sol sur la qualité des cours d’eau en utilisant le cadre DPSIR : application sur le bassin de la Saône

International audienceLes cours d’eau sont des systèmes fragiles et complexes dont le fonctionnement peut être altéré par les activités anthropiques. Guidée par des cadres législatifs stricts et ambitieux, la gestion des cours d’eau implique de nombreux acteurs ayant chacun des objectifs propres en fonction des échelles auxquelles ils opèrent. La littérature identifie clairement l’occupation du sol comme une variable clé de l’estimation des pressions qu’elles soient positives ou négatives. Evaluer les impacts multi échelle de l’occupation du sol sur la qualité des cours d’eau est une question majeure pour les gestionnaires et les scientifiques. L’objectif de notre communication est de présenter l’adaptation du cadre conceptuel DPSIR (" driving forces, pressures, state, impact, responses ") de l’Agence Européenne de l'environnement pour structurer les informations et la construction des indicateurs. Les drivers et les pressions sont estimés à partir des données d'occupation du sol et les données d'états et d'impacts sont estimées par les valeurs d'IBGN et de l'EQR-IBGN, les réponses sont exprimées en termes de potentialités de restauration. Le bassin de la Saône a été choisi comme bassin d’application, en raison de ses caractéristiques hydrogéographiques (superficie de 30 000km² et 9000km de cours d’eau) et de la diversité des activités anthropiques présentes. / Rivers’ functioning can be altered by human activities. Guided by ambitious and rigorous legislative frameworks, rivers management involves many actors, each with specific objectives depending on the scales at which they operate. The literature clearly shows land use as a key variable in the estimation of positive and negative pressures. Assess multi-scale impacts of land use on river water quality is a major issue for water managers and scientist. The aim of our paper is to present the adaptation of DPSIR conceptual framework ("driving forces, pressures, state, impact, responses") promoted by the European Environment Agency to structure the information and the way to build indicators. Drivers and pressures indicators are estimated by land use data. State indicators and impacts indicators are respectively estimated by IBGN and EQR-IBGN values. Responses indicators are characterized by a riverside restoration potentiality. The study case is the Saone catchment because of its hydrogeographical characteristics (area of 30 000km ² and 9000km of rivers) and because of the diversity of human activities in the basin

A large scale evaluation of TBProfiler and Mykrobe for antibiotic resistance prediction in Mycobacterium tuberculosis

Recent years saw a growing interest in predicting antibiotic resistance from whole-genome sequencing data, with promising results obtained for Staphylococcus aureus and Mycobacterium tuberculosis. In this work, we gathered 6,574 sequencing read datasets of M. tuberculosis public genomes with associated antibiotic resistance profiles for both first and second-line antibiotics. We performed a systematic evaluation of TBProfiler and Mykrobe, two widely recognized softwares allowing to predict resistance in M. tuberculosis. The size of the dataset allowed us to obtain confident estimations of their overall predictive performance, to assess precisely the individual predictive power of the markers they rely on, and to study in addition how these softwares behave across the major M. tuberculosis lineages. While this study confirmed the overall good performance of these tools, it revealed that an important fraction of the catalog of mutations they embed is of limited predictive power. It also revealed that these tools offer different sensitivity/specificity trade-offs, which is mainly due to the different sets of mutation they embed but also to their underlying genotyping pipelines. More importantly, it showed that their level of predictive performance varies greatly across lineages for some antibiotics, therefore suggesting that the predictions made by these softwares should be deemed more or less confident depending on the lineage inferred and the predictive performance of the marker(s) actually detected. Finally, we evaluated the relevance of machine learning approaches operating from the set of markers detected by these softwares and show that they present an attractive alternative strategy, allowing to reach better performance for several drugs while significantly reducing the number of candidate mutations to consider

Controlling Microgrids Without External Data: A Benchmark of Stochastic Programming Methods

Microgrids are local energy systems that integrate energy production, demand, and storage units. They are generally connected to the regional grid to import electricity when local production and storage do not meet the demand. In this context, Energy Management Systems (EMS) are used to ensure the balance between supply and demand, while minimizing the electricity bill, or an environmental criterion. The main implementation challenges for an EMS come from the uncertainties in the consumption, the local renewable energy production, and in the price and the carbon intensity of electricity. Model Predictive Control (MPC) is widely used to implement EMS but is particularly sensitive to the forecast quality, and often requires a subscription to expensive third-party forecast services. We introduce four Multistage Stochastic Control Algorithms relying only on historical data obtained from on-site measurements. We formulate them under the shared framework of Multistage Stochastic Programming and benchmark them against two baselines in 61 different microgrid setups using the EMSx dataset. Our most effective algorithm produces notable cost reductions compared to an MPC that utilizes the same uncertainty model to generate predictions, and it demonstrates similar performance levels to an ideal MPC that relies on perfect forecasts

Enfoques de optimización multi-objetivo basados en preferencias en la ingeniería de software

La Ingeniería de Software Basada en Búsqueda (ISBB) estudia la aplicación de técnicas de optimización metaheurística a problemas de la Ingeniería de Software (IS). Una vez que una tarea de la IS se enmarca en un problema de búsqueda existen multitud de algoritmos que pueden aplicarse para resolver ese problema. La mayoría del trabajo existente trata a los problemas de la IS desde un punto de vista mono-objetivo. Sin embargo, muchos de estos problemas poseen múltiples objetivos en conflicto que deben ser optimizados. El número de objetivos a considerar es, en general, alto (esto es, más de tres objetivos). Si bien la comunidad científica ha propuesto varios enfoques de solución para atacar la optimización multi-objetivo, muchos de estos enfoques nos se han aplicado aún en la ISBB. Uno de estos enfoques es el llamado “basado en preferencias”, el cual permite incorporar las preferencias entre los objetivos del tomador de decisiones, restringiendo el frente Paretoóptimo a una zona de interés específica, facilitando de esta manera la tarea de tomar una decisión.Eje: Ingeniería del Software.Red de Universidades con Carreras en Informátic

Enfoques de optimización multi-objetivo basados en preferencias en la ingeniería de software

La Ingeniería de Software Basada en Búsqueda (ISBB) estudia la aplicación de técnicas de optimización metaheurística a problemas de la Ingeniería de Software (IS). Una vez que una tarea de la IS se enmarca en un problema de búsqueda existen multitud de algoritmos que pueden aplicarse para resolver ese problema. La mayoría del trabajo existente trata a los problemas de la IS desde un punto de vista mono-objetivo. Sin embargo, muchos de estos problemas poseen múltiples objetivos en conflicto que deben ser optimizados. El número de objetivos a considerar es, en general, alto (esto es, más de tres objetivos). Si bien la comunidad científica ha propuesto varios enfoques de solución para atacar la optimización multi-objetivo, muchos de estos enfoques nos se han aplicado aún en la ISBB. Uno de estos enfoques es el llamado “basado en preferencias”, el cual permite incorporar las preferencias entre los objetivos del tomador de decisiones, restringiendo el frente Paretoóptimo a una zona de interés específica, facilitando de esta manera la tarea de tomar una decisión.Eje: Ingeniería del Software.Red de Universidades con Carreras en Informátic

Enfoques de optimización multi-objetivo basados en preferencias en la ingeniería de software

La Ingeniería de Software Basada en Búsqueda (ISBB) estudia la aplicación de técnicas de optimización metaheurística a problemas de la Ingeniería de Software (IS). Una vez que una tarea de la IS se enmarca en un problema de búsqueda existen multitud de algoritmos que pueden aplicarse para resolver ese problema. La mayoría del trabajo existente trata a los problemas de la IS desde un punto de vista mono-objetivo. Sin embargo, muchos de estos problemas poseen múltiples objetivos en conflicto que deben ser optimizados. El número de objetivos a considerar es, en general, alto (esto es, más de tres objetivos). Si bien la comunidad científica ha propuesto varios enfoques de solución para atacar la optimización multi-objetivo, muchos de estos enfoques nos se han aplicado aún en la ISBB. Uno de estos enfoques es el llamado “basado en preferencias”, el cual permite incorporar las preferencias entre los objetivos del tomador de decisiones, restringiendo el frente Paretoóptimo a una zona de interés específica, facilitando de esta manera la tarea de tomar una decisión.Eje: Ingeniería del Software.Red de Universidades con Carreras en Informátic

Multi-scale characterisation of a microalloyed TRIP-assisted bainitic steel

Les aciers avancés à haute résistance (AHSS) de 3ème génération ont l’avantage de combiner résistance et ductilité. Ces aciers multi-phasés sont appréciés pour les applications dans l’industrie automobile pour leurs propriétés mécaniques, dues notamment à la présence d’austénite métastable permettant une transformation induite par la plasticité (effet TRIP- Transformation Induced Plasticity).L’objectif de ce travail a été d’étudier l’effet du microalliage sur les transformations de phases et la précipitation dans de tels aciers. Trois nuances ont été étudiées : une référence sans microalliage, une avec ajout de niobium et une avec ajout de vanadium. Elles ont été caractérisées au fil de la route métallurgique composée d’un recuit intermédiaire et d’un recuit final caractéristique des aciers bainitiques à effet TRIP.Des méthodes ex-situ et in-situ ont été mises en oeuvre. Les caractérisations in-situ pendant les traitements thermiques incluent une étude des transformations de phases par diffraction de rayons X à haute énergie (HEXRD) et une étude de la précipitation par diffusion de rayons X à petits angles (SAXS), utilisant le rayonnement synchrotron.La morphologie des grains a été observée par microscopie optique et diffraction d'électrons rétrodiffusés (EBSD) au Microscope Electronique à Balayage (MEB). L’imagerie des précipités a été effectuée par Microscopie Electronique en Transmission (MET) en imagerie en champ sombre, leur composition a été précisée par analyse dispersive en énergie (EDS) et leur localisation étudiée grâce à l’outil de nano-diffraction ACOM/ASTAR.L’ensemble de ces expériences a permis de mettre en évidence l’effet du traitement thermique et de la composition chimique sur la quantité d’austénite présente ainsi que sur sa teneur en carbone, qui sont les principaux paramètres contrôlant l’effet TRIP. La présence du microalliage se traduit par des variations de ces paramètres, liés à la fois à la présence de précipités contenant ces éléments et à leur présence en solution solide.3rd generation Advanced High Strength Steels (AHSS) have the advantage of combining strength and ductility. These multi-phase steels are appreciated for applications in the automotive industry for their mechanical properties, notably due to the presence of metastable austenite allowing Tranformation Induced Plasticity (TRIP effect).The objective of this work was to study the effect of microalloying on phase transformations and precipitation in such steels. Three grades have been studied: a reference without microalloying, one with niobium addition, and one with vanadium addition. They have been characterised through the metallurgical route composed of an intermediate annealing, following by a final annealing characteristic of TRIP-assisted bainitic steels.Both ex-situ and in-situ methods have been applied. In-situ characterisation during thermal treatments includes phase transformation study by High-Energy X-ray Diffraction (HEXRD) and precipitation study by Small Angle X-ray Scattering (SAXS), both performed with synchrotron radiation.Grain morphology has been observed by optical microscopy and Electron Back-Scatter Diffraction (EBSD) in a Scanning Electron Microscope (SEM). Imaging of precipitates has been made in Transmission Electron Microscopy (TEM) via dark-field imaging, their composition has been evauated by Energy Dispersive Spectroscopy (EDS) and their localization studied thanks to the nano-diffraction tool ACOM/ASTAR.All these experiments made it possible to highlight the effect of heat treatment and chemical composition on the amount of austenite present and on its carbon content, which are the main parameters controlling the TRIP effect. The presence of the microalloying results in variations in these parameters, related both to the presence of precipitates containing these elements and to their presence in solid solution