Université de Neuchâtel

Recharge quantification and continental freshwater lens dynamics in arid regions : application to the Merti aquifer (eastern Kenya)

Blandenier, Lucien ; Perrochet, Pierre (Dir.) ; Milnes, Ellen (Codir.) ; Brunner, Philip (Codir.)

Thèse de doctorat : Université de Neuchâtel, 2015.

The Dadaab refugee camp, the largest refugee camp in the world with a population of approximately 400’000 persons, is located in the arid to semi-arid eastern Kenya, close to the Somali border. The only permanent water resource for the refugees and the host communities comes from the Merti aquifer which consists in a large continental freshwater lens of 250 km by 50 km surrounded by salty...

Université de Neuchâtel

Assessing the impact of thermal feedback and recycling in open-loop groundwater heat pump (GWHP) systems : a complementary design tool

Milnes, Ellen ; Perrochet, Pierre

In: Hydrogeology Journal, 2013, vol. 21, no. 2, p. 505-514

Thermal feedback and thermal recycling in open-loop groundwater heat pump (GWHP) systems occurs when a fraction of the injected water in a well doublet returns to the production well. They reflect two different mathematical representations of the same physical process. Thermal feedback assumes a constant injection temperature, while thermal recycling couples the injection and...

Université de Neuchâtel

Sondages géoélectriques "null-arrays" pour la caractérisation des structures de subsurface

Falco, Pierik ; Perrochet, Pierre (Dir.) ; Milnes, Ellen (Codir.)

Thèse de doctorat : Université de Neuchâtel, 2013.

The term "geoelectric null-array" is used for those geoelectrical configurations measuring a zero potential difference above a homogenous half-space. This thesis presents a study of the behaviour of three of these null-arrays - the midpoint null-array, the Wenner-γ null-array and the Schlumberger null-array - above different vertical structures, using profiling and azimuthal measurements. A...

Université de Neuchâtel

Fracture characterisation using geoelectric null-arrays

Falco, Pierik ; Negro, François ; Szalai, Sándor ; Milnes, Ellen

In: Journal of Applied Geophysics, 2013, vol. 93, p. 33-42

The term “geoelectric null-array” is used for direct current electrode configurations yielding a potential difference of zero above a homogeneous half-space. This paper presents a comparative study of the behaviour of three null-arrays, midpoint null-array (MAN), Wenner-γ null-array and Schlumberger null-array in response to a fracture, both in profiling and in azimuthal mode. The main...

Université de Neuchâtel

Modelling Discharge Rates and Ground Settlement Induced by Tunnel Excavation

Preisig, Giona ; Dematteis, A. ; Torri, R ; Monin, N. ; Milnes, Ellen ; Perrochet, Pierre

In: Rock Mechanics and Rock Engineering, 2014, vol. 47, no. 3, p. 869-884

Interception of aquifers by tunnel excavation results in water inflow and leads to drawdown of the water table which may induce ground settlement. In this work, analytical and numerical models are presented which specifically address these groundwater related processes in tunnel excavation. These developed models are compared and their performance as predictive tools is evaluated. Firstly, the...

Université de Neuchâtel

Process-based groundwater salinisation risk assessment methodology: Application to the Akrotiri aquifer (Southern Cyprus)

Milnes, Ellen

In: Journal of Hydrology, 2011, vol. 399, no. 1-2, p. 29-47

Groundwater salinisation is a major groundwater contamination issue world-wide and can be caused by different processes, such as seawater intrusion, agrochemical pollution, geogenic contamination and irrigation-induced salinisation. In many areas, several salinisation processes are superimposed. Since remedial measures vary for different salinisation processes, correct identification is...

Université de Neuchâtel

Markierungsversuche und Modellierung zur Bewertung der Gefährdung eines Trinkwasserbrunnens = Tracer experiments and modelling for risk assessment of a drinking water well

Goldscheider, Nicola ; Milnes, Ellen ; Fries, W. ; Joppen, M.

In: Grundwasser, 2008, vol. 13, no. 4, p. 220-230

A tracer experiment with uranine in a gravel aquifer aimed to assess the risk of a drinking water well near Pratteln, Switzerland, resulting from a contaminated site 760 m further upgradient. The experiment revealed a maximum linear flow velocity of 127 m/d and a mass recovery of 0.93 %. The tracer was also detected at two intermediate monitoring wells. This paper discusses the causes of...

Université de Neuchâtel

Simultaneous identification of a single pollution point-source location and contamination time under known flow field conditions

Milnes, Ellen ; Perrochet, Pierre

In: Advances in Water Resources, 2007, vol. 30, no. 12, p. 2439-2446

A theoretical framework is presented that allows direct identification of a single point-source pollution location and time in heterogeneous multidimensional systems under known flow field conditions. Based on the concept of the transfer function theory, it is shown that an observed pollution plume contains all the necessary information to predict the concentration at the unknown pollution source...

Université de Neuchâtel

Direct simulation of solute recycling in irrigated areas

Milnes, Ellen ; Perrochet, Pierre

In: Advances in Water Resources, 2006, vol. 29, no. 8, p. 1140-1154

Solute recycling from irrigation can be described as the process that occurs when the salt load that is extracted from irrigation wells and distributed on the fields is returned to the groundwater below irrigated surfaces by deep percolation. Unless the salt load leaves the system by means of drains or surface runoff, transfer to the groundwater will take place, sooner or later. This can lead to...

See also: similar author names
2 Milnes, E.
1 Milnes, Ellen ;