Accès public à partir du 24 févr. 2020
Université de Neuchâtel

Can one identify karst conduit networks geometry and properties from hydraulic and tracer test data?

Borghi, Andrea ; Renard, Philippe ; Cornaton, Fabien

In: Advances in Water Resources, 2016, vol. 90, p. 99-115

Karst aquifers are characterized by extreme heterogeneity due to the presence of karst conduits embedded in a fractured matrix having a much lower hydraulic conductivity. The resulting contrast in the physical properties of the system implies that the system reacts very rapidly to some changes in the boundary conditions and that numerical models are extremely sensitive to small modifications in...

Université de Neuchâtel

Stochastic fracture generation accounting for the stratification orientation in a folded environment based on an implicit geological model

Borghi, Andrea ; Renard, Philippe ; Fournier, L ; Negro, François

In: Engineering Geology, 2015, vol. 187, p. 135-142

This paper presents a new approach in generating stochastic discrete fracture networks. The particularity of the approach is that it allows us to simulate the theoretical families of fractures that are expected in a folded environment. The approach produces fractures that are consistent with the local stratigraphic orientation. The fractures are modeled as simple rectangular planar objects. When...

Université de Neuchâtel

Generation of 3D Spatially Variable Anisotropy for Groundwater Flow Simulations

Borghi, Andrea ; Renard, Philippe ; Courrioux, Gabriel

In: Groundwater, 2015, vol. 53, no. 6, p. 955-958

Sedimentary units generally present anisotropy in their hydraulic properties, with higher hydraulic conductivity along bedding planes, rather than perpendicular to them. This common property leads to a modeling challenge if the sedimentary structure is folded. In this paper, we show that the gradient of the geological potential used by implicit geological modeling techniques can be used to...

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

A method for the stochastic modeling of karstic systems accounting for geophysical data : an example of application in the region of Tulum, Yucatan Peninsula (Mexico)

Vuilleumier, Cécile ; Borghi, Andrea ; Renard, Philippe ; Ottowitz, David ; Schiller, A. ; Supper, Robert ; Cornaton, Fabien

In: Hydrogeology Journal, 2013, vol. 21, no. 9, p. 523-544

The eastern coast of the Yucatan Peninsula, Mexico, contains one of the most developed karst systems in the world. This natural wonder is undergoing increasing pollution threat due to rapid economic development in the region of Tulum, together with a lack of wastewater treatment facilities. A preliminary numerical model has been developed to assess the vulnerability of the resource. Maps of...

Université de Neuchâtel

A pseudo-genetic stochastic model to generate karstic networks

Borghi, Andrea ; Renard, Philippe ; Jenni, Sandra

In: Journal of Hydrology, 2012, vol. 414-415, p. 516-529

In this paper, we present a methodology for the stochastic simulation of 3D karstic conduits accounting for conceptual knowledge about the speleogenesis processes and accounting for a wide variety of field measurements. The methodology consists of four main steps. First, a 3D geological model of the region is built. The second step consists in the stochastic modeling of the internal...