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

Modeling Fine-Scale Geological Heterogeneity : Examples of Sand Lenses in Tills

Kessler, Timo Christian ; Comunian, Alessandro ; Oriani, Fabio ; Renard, Philippe ; Nilsson, Bertel ; Klint, Knud Erik ; Bjerg, Poul Løgstrup

In: Ground Water, 2013, vol. 51, no. 5, p. 692-705

Sand lenses at various spatial scales are recognized to add heterogeneity to glacial sediments. They have high hydraulic conductivities relative to the surrounding till matrix and may affect the advective transport of water and contaminants in clayey till settings. Sand lenses were investigated on till outcrops producing binary images of geological cross-sections capturing the size, shape and...

Université de Neuchâtel

Three-dimensional high resolution fluvio-glacial aquifer analog - Part 2: Geostatistical modeling

Comunian, Alessandro ; Straubhaar, Julien ; Renard, Philippe ; Bayer, P.

In: Journal of Hydrology, 2011, vol. 405, no. 1, p. 10

The heterogeneity of sedimentary structures at the decimeter scale is crucial to the understanding of groundwater flow and transport. In a series of two papers, we provide a detailed analysis of a fluvio-glacial aquifer analog: the Herten site. The geological data along a series of 2D sections in a quarry, the corresponding GPR measurements, and their sedimentological interpretation are described...

Université de Neuchâtel

Three-dimensional high resolution fluvio-glacial aquifer analog - Part 1: Field study

Bayer, P. ; Huggenberger, P. ; Renard, Philippe ; Comunian, Alessandro

In: Journal of Hydrology, 2011, vol. 405, no. 1, p. 1

Describing the complex structures that exist in many sedimentary aquifers is crucial for reliable groundwater flow and transport simulation. However, hardly any aquifer can be inspected in such detail that all decimeter to meter heterogeneity is resolved. Aquifer analogs serve as surrogates to construct models of equivalent heterogeneity, and thus imitate those features relevant for flow or...

Université de Neuchâtel

Probability aggregaton methods and multiple-point statistics for 3D modeling of aquifer heterogeneity from 2D training images

Comunian, Alessandro ; Renard, Philippe (Dir.) ; Straubhaar, Julien (Codir.)

Thèse de doctorat : Université de Neuchâtel, 2011 ; 2187.

Multiple-point statistics (MPS) is a rising method for the characterization of heterogeneity. Its strength and its Achilles' heel lie in the training image, which is the conceptual model of geological heterogeneity on which MPS simulations are based. Indeed, on one side the use of the training image allows great flexibility when for example for bi-dimensional (2D) simulation a training image can...

Université de Neuchâtel

Introducing wwhypda : a world-wide collaborative hydrogeological parameters database

Comunian, Alessandro ; Renard, Philippe

In: Hydrogeology Journal, 2009, vol. 17, no. 2, p. 481-489

Depuis la publication des travaux originaux de Henry Darcy (datés 1880) de très nombreuses valeurs de propriétés physiques des roches (conductivité hydraulique, perméabilité, compressibilité, porosité, etc.) ont été obtenues expérimentalement et publiées. Ces données sont toutefois dispersées et donc difficiles d’accès. Pour palier à ce problème et pour ainsi faciliter la...