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

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

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

A conceptual model of flow and transport in a karst aquifer based on spatial and temporal variations of natural tracers

Perrin, Jérôme ; Zwahlen, François (Dir.) ; Jeannin, Pierre-Yves (Codir.)

Thèse de doctorat : Université de Neuchâtel : 2003 ; 1699.

Karst aquifers represent an important groundwater resource world-wide. They are highly vulnerable to contamination due to fast transport through the system and limited attenuation of contaminants. The two main hydrogeological approaches developed for studying flow and transport are: inference of the system structure from karst spring hydrographs and chemographs; numerical modelling of flow and...

Université de Neuchâtel

Virus transport and attenuation in Perialpine Gravel Aquifers

Flynn, Raymond Matthew ; Zwahlen, François (Dir.) ; Hunkeler, Daniel (Codir.)

Thèse de doctorat : Université de Neuchâtel : 2003 ; 1720.

Pollution of groundwater by microbiological contaminants (bacteria, viruses and protozoa) is a widespread problem in the United States and Europe. Gravel aquifers, which form an important drinking water resource in many parts of Central Europe, may be highly vulnerable to this type of contamination. Due to the smaller size and perceived greater mobility, studies of microbiological contaminant...