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Université de Neuchâtel

Gas supersaturation, 222Rn and CO2 as tracers in karst water

Babić, Domagoj ; Zwahlen, François (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2014.

Karst aquifers are among the most important water resources world-wide. Nevertheless, due to their intrinsic properties consisting in fast transport processes and reduced contaminant attenuation capacity, they are proved to be highly vulnerable. Consequently, it is important to discriminate between water originating from the soil reservoir, the epikarst, the low permeability volume and the...

Université de Neuchâtel

Estimation et cartographie de la vulnérabilité des eaux souterraines en milieu urbain

Ducommun, Romain ; Zwahlen, François (Dir.) ; Perrochet, Pierre (Codir.) ; Dassargues, Alain (Codir.) ; Mudry, Jacques (Codir.)

Thèse de doctorat : Université de Neuchâtel, 2010.

Vulnerability assessments and mapping methods for groundwater were primarily designed for rural and natural areas. In urban areas, urban-specific elements like underground pipes, a concentrated runoff on sealed surfaces, or the presence of artificial materials in the unsaturated zone impact surface water infiltration and water percolation in the unsaturated zone – processes that strongly affect...

Université de Neuchâtel

Origin and behaviour of microorganisms and particles in selected karst aquifer systems

Pronk, Michiel ; Zwahlen, François (Dir.) ; Goldscheider, Nico (Codir.)

Thèse de doctorat : Université de Neuchâtel, 2008 ; Th. 2101.

Karst aquifers represent an important groundwater resource world-wide. They are, however, highly vulnerable to contamination due to fast transport and limited contaminant attenuation processes encountered in such systems. Pathogenic microorganisms are among the most frequent and problematic contaminants in groundwater from karst aquifers. It is generally accepted that the presence of faecal...

Université de Neuchâtel

Spotlight on heterogeneity : measuring and modelling stream-aquifer interactions

Kalbus, Edda ; Zwahlen, François (Dir.) ; Schirmer, Mario (Codir.)

Thèse de doctorat : Université de Neuchâtel, 2009 ; Th. 2086.

Interactions between groundwater and streams play an important role for the functioning of stream ecosystems. Most nutrient cycling and stream metabolism takes place in the transition zone between aquifers and streams. Since flow patterns are the major controlling factor for the transformation of dissolved compounds in the transition zone, the characterization and quantification of flow is an...

Université de Neuchâtel

Water and contaminant fluxes at the stream-groundwater-interface

Schmidt, Christian ; Zwahlen, François (Dir.) ; Schirmer, Mario (Codir.)

Thèse de doctorat : Université de Neuchâtel, 2009 ; Th. 2087.

Streams and groundwater are inherently connected. In temperate climates, for instance, groundwater discharge to streams supplies the baseflow component of streamflow. Groundwater sustains streamflow in dry periods and is therefore critical for maintaining aquatic ecosystems and wetlands. Water fluxes between groundwater and streams also mediate the transport of contaminants between these two...

Université de Neuchâtel

Les isotopes radioactifs de la série de l’uranium-238 (222Rn, 226Ra, 234U et 238U) dans les eaux thermales de Suisse : sites d’Yverdon-les-Bains, Moiry, Loèche-les-Bains, Saxon, Val d’Illiez, Bad Ragaz, Delémont, Lavey-les-Bains, Brigerbad et Combioula

Gainon, François ; Zwahlen, François (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2008 ; Th.2029.

Isotopes of the 238U series are naturally occurring in groundwater. The aim of this work is to measure 4 isotopes of this series (222Rn, 226Ra, 238U and 234U) in the context of deep groundwater, to study their geochemical behavior and finally to use this information for a better understanding of deep aquifers. The test sites are situated in...

Université de Neuchâtel

Morphologies of conductive structures inside and around the Las Cañadas caldera, Tenerife, Canary islands

Coppo, Nicolas ; Zwahlen, François (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2007 ; Th.1975.

Being an extremely heterogeneous medium, electric resistivity of volcanic rocks extends over a large range. This physical property is strongly related to the minerals that form these rocks, to the electrical conductivity of fluids that may soak through the rocks, or to the bulk porosity. The spatial distribution of this property allows to infer internal structures of a volcanic edifice and to...

Université de Neuchâtel

Détermination des paramètres hydrauliques et hydrochimiques d'un aquifère alluvial dans une vallée alpine (Valais, Suisse)

Schürch, Marc ; Zwahlen, François (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2000 ; 1502.

Dans la vallée du Rhône en amont de la ville de Sierre (Valais central), le site du Bois de Finges est caractérisé par de multiples environnements géologiques quaternaires : les alluvions fluviatiles du Rhône, les alluvions du cône de déjection de l'Illgraben, les dépôts de l'éboulement de Sierre et les éboulis du versant sud. L'aquifère des alluvions fluviatiles du Rhône est...

Université de Neuchâtel

Aquifères karstiques et poreux de l'Ajoie (Jura, Suisse) : éléments pour la carte hydrogéologique au 1:25'000

Gretillat, Pierre-Alain ; Zwahlen, François (Dir.)

Thèse de doctorat : Université de Neuchâtel, 1998 ; 1452.

L'Ajoie est située dans le prolongement méridional du Fossé Rhénan, au pied de la dernière chaîne du Jura plissé et à l'extrémité orientale du jura tabulaire français. Dans un environnement essentiellement karstique, les aquifères alluviaux d'Ajoie ont cependant une importance primoidiale, malgré leur extension limitée, dans l'ex'ploitation des ressources en eau potable de toute la...