The IAHS Science for Solutions decade, with Hydrology Engaging Local People IN one Global world (HELPING)

The new scientific decade (2023-2032) of the International Association of Hydrological Sciences (IAHS) aims at searching for sustainable solutions to undesired water conditions – whether it be too little, too much or too polluted. Many of the current issues originate from global change, while solutions to problems must embrace local understanding and context. The decade will explore the current water crises by searching for actionable knowledge within three themes: global and local interactions, sustainable solutions and innovative cross-cutting methods. We capitalise on previous IAHS Scientific Decades shaping a trilogy; from Hydrological Predictions (PUB) to Change and Interdisciplinarity (Panta Rhei) to Solutions (HELPING). The vision is to solve fundamental water-related environmental and societal problems by engaging with other disciplines and local stakeholders. The decade endorses mutual learning and co-creation to progress towards UN sustainable development goals. Hence, HELPING is a vehicle for putting science in action, driven by scientists working on local hydrology in coordination with local, regional, and global processes

One consensual depression diagnosis tool to serve many countries: a challenge! A RAND/UCLA methodology

Objective From a systematic literature review (SLR), it became clear that a consensually validated tool was needed by European General Practitioner (GP) researchers in order to allow multi-centred collaborative research, in daily practice, throughout Europe. Which diagnostic tool for depression, validated against psychiatric examination according to the DSM, would GPs select as the best for use in clinical research, taking into account the combination of effectiveness, reliability and ergonomics? A RAND/UCLA, which combines the qualities of the Delphi process and of the nominal group, was used. GP researchers from different European countries were selected. The SLR extracted tools were validated against the DSM. The Youden index was used as an effectiveness criterion and Cronbach’s alpha as a reliability criterion. Ergonomics data were extracted from the literature. Ergonomics were tested face-to-face. Results The SLR extracted 7 tools. Two instruments were considered sufficiently effective and reliable for use: the Hospital Anxiety and Depression Scale and the Hopkins Symptoms Checklist-25 (HSCL-25). After testing face-to-face, HSCL-25 was selected. A multicultural consensus on one diagnostic tool for depression was obtained for the HSCL-25. This tool will provide the opportunity to select homogeneous populations for European collaborative research in daily practice

Selection of calibration objective fonctions in the context of rainfall-ronoff modelling in a Sudanese savannah area

International audienc

1. - Evaluation des ressources en eau dans le Nord-Ouest de la Côte d’ivoire. Extension aux bassins versants non jaugés

All the developing projects realized in the North of Ivory Coast need a good water resources management. It is the reason why rainfall-runoff modelization has been performed over 16 catchments (100 to 4500 km2). The aim was to characterize the values of the parameters of the models, so that these algorithms can be used for simulations over ungauged catchments. The significance of the land use is clearly demonstrated. The variables which characterize the land use are always part of the equations that predetermine the values of the models parameters. These relations have been tested. They allow a good fit between observed and calculated annual hydrograms.Les différents projets de développement élaborés et réalisés dans le Nord de la Côte d’ivoire nécessitent une bonne maîtrise de la gestion des ressources en eau. C'est dans cette optique qu'ont été réalisés des travaux de modélisation de la relation pluie-débit sur 16 bassins versants (100 à 4500 km2). L'objectif était de caractériser les valeurs des paramètres après calage, afin de pouvoir utiliser ces algorithmes en simulation sur des bassins versants non jaugés ou mal connus. L'importance de l'occupation des sols apparaît clairement. Les variables qui la caractérisent entrent systématiquement dans les relations établies pour prédéterminer les valeurs des paramètres des modèles, permettant d'améliorer très sensiblement la validité de ces relations et donc la qualité des résultats qui en découlent. Ces relations ont été validées et testées. Elles présentent un niveau d'adéquation satisfaisant entre hydrogrammes annuels observés et calculés.Servat E., Dezetter A. 1. - Evaluation des ressources en eau dans le Nord-Ouest de la Côte d’ivoire. Extension aux bassins versants non jaugés. In: L'avenir de l'eau. Quelques réponses des sciences hydrotechniques à une inquiétude mondiale. Vingt deuxièmes journées de l'hydraulique. Paris, 15-17 septembre 1992. Tome 3, 1992

Sensitivity analysis of hydrological modelling to climate forcing in a semi-arid mountainous catchment.

International audienceThis study analyses the sensitivity of a hydrological model to different ways of interpolatingclimate forcing on the Elqui basin (5660 km2) in the Chilean Andes. A 36-year period (1976–2011) waschosen in order to account for the hydro-climatic variability. Precipitation and using the inverse distanceweighted methods were interpolated on a 5 × 5 km grid based on 12 and eight stations, respectively. Elevation effects on precipitation and temperature distribution were considered using a digital elevationmodel. Two precipitation datasets (with and without a mean altitudinal gradient) and three temperaturedatasets (using constant or monthly lapse rates based on altitudinal bands) were computed. All datasetcombinations were assessed through the calibration of the GR4j model including a snow reservoir.Calibration was performed by the succession of Rosenbrock and simplex algorithms using a multi-objectivefunction. Results show that the dataset based on a constant lapse rate of 6.5°C/km for temperature and noelevation effects for precipitation is sufficient to accurately simulate discharge and the snowmelt regime ofthe catchment over the last 30 years

Impacts de la variabilité climatique et anthropique sur les ressources en eau du bassin versant du Tensift – Maroc

International audienc

Rainfall-runoff modelling of water resources in the upper Senegal River basin

The streamflow series for the upstream basin of the Senegal River is marked by considerable gaps. The objective of this article is to simulate and extend hydrological data, using the GR2M rainfall-runoff model. A sensitivity analysis of the model to rainfall and water holding capacity input data was performed. This analysis was performed after calculating catchment rainfall, mean potential evapotranspiration, and maximum, minimum and mean water holding capacity. The best combination of input data was chosen by catchment based on the Nash-Sutcliffe criterion. Then cross calibration-validation tests were performed, using the selected input data to choose model parameter sets