Amélioration de la dynamique

Les cours d’eau proches de l’état naturel sont des systèmes dynamiques: le lit et les rives sont régulièrement modi!és par des crues, entraînant la création de nouveaux habitats. Durant les dernières décennies, cette dynamique a souvent été restreinte suite à l’endiguement de nombreuses rivières. Son rétablissement est un objectif important des revitalisations. Cette fiche présente les bases nécessaires à l’amélioration de cette dynamique

Förderung der Dynamik bei Revitalisierungen

Naturnahe Fliessgewässer sind dynamische Systeme: Gewässersohle und Ufer werden regelmässig durch Hochwasser umgestaltet, wodurch neue Lebensräume entstehen. In den letzten Jahrzehnten wurde diese Dynamik vielerorts eingeschränkt, weil zahlreiche Fliessgewässer verbaut wurden. Ein wichtiges Ziel von Revitalisierungen ist, sie wiederherzustellen. Das vorliegende Merkblatt präsentiert Grundlagen für die Förderung der Dynamik

Flussrevitalisierungen: eine Übersicht

Das Forschungsprojekt «Integrales Flussgebietsmanagement» erarbeitete ökologische und wasserbauliche Grundlagen zur Revitalisierung von Fliessgewässern und unterstützt so deren Planung und Umsetzung. Die vorliegende Merkblatt-Sammlung präsentiert Ergebnisse dieses transdisziplinären Projekts von Eawag, WSL, LCH-EPFL und VAW-ETHZ und richtet sich an Fachleute in Bundesämtern, kantonalen Ämtern sowie Ingenieur- und Ökobüros

Biodiversität in Fliessgewässern

Vielfältige, naturnahe und dynamische Lebensräume sind eine wichtige Voraussetzung dafür, die Biodiversität in Fliessgewässern zu erhalten und zu fördern. Das vorliegende Merkblatt stellt die wichtigsten Faktoren für die Lebensraum- und Artenvielfalt vor und präsentiert Empfehlungen, mit welchen Massnahmen die Biodiversität erhöht werden kann

Biodiversité dans les cours d’eau

Des habitats diversifiés, dynamiques et proches de l’état naturel sont indispensables à la conservation et à l’amélioration de la biodiversité dans les cours d’eau. Cette fiche présente les principaux facteurs de la diversité des habitats et des espèces, ainsi que des mesures permettant d’accroître la biodiversit

Programme national de lutte contre le VIH, les IST et l’hépatite virale: unir les forces contre le VIH et les hépatites virales

La Stratégie suisse contre l’hépatite a – tout comme l’Organisation mondiale de la Santé (OMS) – pour objectif d’éliminer l’hépatite B et C d’ici 2030. Cela signifie que les taux de nouvelles infections et des séquelles doivent être ramenés à proche de zéro. Tous les instruments d’élimination, c’est-à-dire les mesures préventives, les thérapies et les vaccinations, sont disponibles. Il s’agit maintenant de combler les lacunes en matière d’éducation, de dépistage et d’accès à la thérapie à bas seuil

InterFrost Project Phase 2: Updated experiment design for validation of Cryohydrogeological codes (Frozen Inclusion)

International audienceRecent field and modelling studies indicate that a fully-coupled, multi-dimensional, thermo-hydraulic (TH) approach is required to accurately model the evolution of permafrost-impacted landscapes and groundwater systems. However, the relatively new and complex numerical codes being developed for coupled non-linear freeze-thaw systems require validation. This issue was first addressed within the InterFrost IPA Action Group, by means of an intercomparison of thirteen numerical codes for two-dimensional TH test cases (TH2 & TH3). The main results (cf. Grenier et al. 2018 and wiki.lsce.ipsl.fr/interfrost) demonstrate that these codes provide robust results for the test cases considered. The second phase of the InterFrost project is devoted to the simulation of a cold-room reference experiment based on test case TH2 (Frozen Inclusion). In a first implementation phase of the experimental setup, the initial frozen inclusion was inserted in the setup prior to the complete filling of the porous medium and the flow initiation. The thermal evolution of the system was monitored by thermistors located at the center of the initial inclusion and along the downgradient centerline. This setup provided optimal conditions to control the initial experiment geometries but resulted in slight differences in the initialization time for different experiments. We present a second implementation strategy that considers "in place" generation of an initial frozen inclusion through a cooling coil. The initial frozen inclusion is obtained after the initial cooling time and its initial thermal state is measured by means of an array of thermistors. In a second step, the flow is initiated, and the thermal evolution is monitored through an array of 11 thermistors (within the initial position and downgradient). The experimental setup and monitoring results as well as preliminary simulation results are presented. Derived results and conclusions from this exercise form the basis for the next phase within the InterFrost validation exercise. Grenier, C. et al. 2018. Groundwater flow and heat transport for systems undergoing freeze-thaw: Inter-comparison of numerical simulators for 2D test cases. Adv. Wat. Res. 114: 196-218

InterFrost Project Phase 2: Updated experiment design for validation of Cryohydrogeological codes (Frozen Inclusion)

22nd EGU General Assembly, held online 4-8 May, 2020International audienceRecent field and modelling studies indicate that a fully-coupled, multi-dimensional, thermo-hydraulic (TH) approach is required to accurately model the evolution of permafrost-impacted landscapes and groundwater systems. However, the relatively new and complex numerical codes being developed for coupled non-linear freeze-thaw systems require validation. This issue was first addressed within the InterFrost IPA Action Group, by means of an intercomparison of thirteen numerical codes for two-dimensional TH test cases (TH2 & TH3). The main results (cf. Grenier et al. 2018 and wiki.lsce.ipsl.fr/interfrost) demonstrate that these codes provide robust results for the test cases considered. The second phase of the InterFrost project is devoted to the simulation of a cold-room reference experiment based on test case TH2 (Frozen Inclusion). In a first implementation phase of the experimental setup, the initial frozen inclusion was inserted in the setup prior to the complete filling of the porous medium and the flow initiation. The thermal evolution of the system was monitored by thermistors located at the center of the initial inclusion and along the downgradient centerline. This setup provided optimal conditions to control the initial experiment geometries but resulted in slight differences in the initialization time for different experiments. We present a second implementation strategy that considers "in place" generation of an initial frozen inclusion through a cooling coil. The initial frozen inclusion is obtained after the initial cooling time and its initial thermal state is measured by means of an array of thermistors. In a second step, the flow is initiated, and the thermal evolution is monitored through an array of 11 thermistors (within the initial position and downgradient). The experimental setup and monitoring results as well as preliminary simulation results are presented. Derived results and conclusions from this exercise form the basis for the next phase within the InterFrost validation exercise. Grenier, C. et al. 2018. Groundwater flow and heat transport for systems undergoing freeze-thaw: Inter-comparison of numerical simulators for 2D test cases