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Université de Neuchâtel

3D multiple-point statistics simulation using 2D training images

Comunian, A. ; Renard, Philippe ; Straubhaar, Julien

In: Computers & Geosciences, 2011, vol. 40, p. 49-65

One of the main issues in the application of multiple-point statistics (MPS) to the simulation of three-dimensional (3D) blocks is the lack of a suitable 3D training image. In this work, we compare three methods of overcoming this issue using information coming from bidimensional (2D) training images. One approach is based on the aggregation of probabilities. The other approaches are novel. One...

Université de Neuchâtel

3D stochastic modeling of karst aquifers using a pseudo-genetic methodology

Borghi, Andrea ; Renard, Philippe (Dir.)

Thèse de doctorat : Université de Neuchâtel, 2013.

Le but de cette thèse est le développement d'une méthodologie de modélisation des aquifères karstiques. Premièrement, la géométrie des conduits karstiques est simulée. La géométrie de ces conduits est contrôlée à large échelle par la géologie (modèle géologique), et à plus petite échelle par la fracturation (modèle stochastique de fracturation). Deuxièmement, ces...

Université de Neuchâtel

Advances in understanding river-groundwater interactions

Brunner, Philip ; Therrien, R ; Renard, Philippe ; Simmons, C.T ; Hendricks Franssen, H-J

In: Reviews of Geophysics, 2017, vol. 55, p. 818-854

River-groundwater interactions are at the core of a wide range of major contemporary challenges, including the provision of high-quality drinking water in sufficient quantities, the loss of biodiversity in river ecosystems, or the management of environmental flow regimes. This paper reviews state of the art approaches in characterizing and modeling river and groundwater interactions. Our review...

Université de Neuchâtel

Analog-based meandering channel simulation

Mariethoz, Gregoire ; Comunian, Alessandro ; Irarrazaval, Inigo ; Renard, Philippe

In: Water Resources Research, 2014, vol. 50, no. 2, p. 836–854

Characterizing the complex geometries and the heterogeneity of the deposits in meandering river systems is a long-standing issue for the 3-D modeling of alluvial formations. Such deposits are important sources of accessible groundwater in alluvial aquifers throughout the world and also play a major role as hydrocarbons reservoirs. In this paper, we present a method to generate meandering river...

Université de Neuchâtel

Analyse morpho-syntaxique du français et enseignement assisté par ordinateur

Renard, Karen

In: Revue Tranel (Travaux neuchâtelois de linguistique), 1986, vol. 11, p. 285-298

Université de Neuchâtel

Application of tritium in precipitation and in groundwater of the Kouris catchment (Cyprus) for description of the regional groundwater flow

Boronina, Anastasia ; Renard, Philippe ; Balderer, Werner ; Stichler, Willibald

In: Applied Geochemistry, 2005, vol. 20, no. 7, p. 1292-1308

The Kouris catchment is located in the south of the Troodos massif in Cyprus. It constitutes one of the biggest catchments of the island with important freshwater resources. Geologically, the catchment includes an ophiolitic complex outcropping in the north which is overlaid by sedimentary rocks in the south. The hydrology is driven by a Mediterranean climate, a mountainous topography, and a...

Université de Neuchâtel

Approximate discharge for constant head test with recharging boundary : Technical Note

Renard, Philippe

In: Ground Water, 2005, vol. 43, no. 3, p. 439-442

The calculation of the discharge to a constant drawdown well or tunnel in the presence of an infinite linear constant head boundary in an ideal confined aquifer usually relies on the numerical inversion of a Laplace transform solution. Such a solution is used to interpret constant head tests in wells or to roughly estimate ground water inflow into tunnels. In this paper, a simple approximate...

Université de Neuchâtel

Assessing the effect of different river water level interpolation schemes on modeled groundwater residence times

Diem, Samuel ; Renard, Philippe ; Schirmer, Mario

In: Journal of Hydrology, 2014, vol. 510, p. 393-402

Obtaining a quantitative understanding of river–groundwater interactions is of high practical relevance, for instance within the context of riverbank filtration and river restoration. Modeling interactions between river and groundwater requires knowledge of the river’s spatiotemporal water level distribution. The dynamic nature of riverbed morphology in restored river reaches might result in...

Université de Neuchâtel

Bayesian inverse problem and optimization with iterative spatial resampling

Mariethoz, Grégoire ; Renard, Philippe ; Caers, Jeff

In: Water Resources Research, 2010, vol. 46, no. W11530, p. 1-17

Measurements are often unable to uniquely characterize the subsurface at a desired modeling resolution. In particular, inverse problems involving the characterization of hydraulic properties are typically ill-posed since they generally present more unknowns than data. In a Bayesian context, solutions to such problems consist of a posterior ensemble of models that fit the data (up to a certain...