Incorporation of geomorphological information into the stochastic simulation of karst conduits

Guillaume Rongier and Pauline Collon and Marco Filipponi. ( 2014 )
in: GeoEnv 2014 Proceedings - 10th conference on Geostatistics for Environmental Applications, 9th-11th July, 2014, Paris, France

Abstract

Karst conduits are strongly related to their local geological context. This relationship is also expressed in their shape, which can be highly complex. Conduit modeling from 2D sections and maps as well as more advanced stochastic approaches tend to generate globally cylindrical or eventually elliptical 3D envelopes, ignoring the impact of the local geology and leading to simplistic shapes. We propose to simulate more realistic conduit shapes by taking into account the local geology in the generation process. Our methodology is based on the Object-Distance Simulation Method (ODSIM) principle: a distance to a skeleton controlling the first-order features is perturbed using a random field controlling finer-scale features. Our proposal is to play on these two scales. First, by including geomorphological information into the ``distance'' field using a fast marching method. This custom ``distance'' field takes into account simultaneously various elements involved in the conduit genesis and so influencing the conduit shapes. Second, we propose to build the random field by combining different variograms and/or distributions following the geomorphological elements taken into account by the fast marching. Different synthetic models show that the generated conduit shapes are closer to what is observed in real conduits than with the previous workflow, while the variability of structures that can be modeled with ODSIM is preserved.

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    BibTeX Reference

    @INPROCEEDINGS{,
        author = { Rongier, Guillaume and Collon, Pauline and Filipponi, Marco },
         title = { Incorporation of geomorphological information into the stochastic simulation of karst conduits },
         month = { "jul" },
     booktitle = { GeoEnv 2014 Proceedings - 10th conference on Geostatistics for Environmental Applications,  9th-11th July, 2014, Paris, France },
          year = { 2014 },
      abstract = { Karst conduits are strongly related to their local geological context. This relationship is also expressed in their shape, which can be highly complex. Conduit modeling from 2D sections and maps as well as more advanced stochastic approaches tend to generate globally cylindrical or eventually elliptical 3D envelopes, ignoring the impact of the local geology and leading to simplistic shapes. We propose to simulate more realistic conduit shapes by taking into account the local geology in the generation process. Our methodology is based on the Object-Distance Simulation Method (ODSIM) principle: a distance to a skeleton controlling the first-order features is perturbed using a random field controlling finer-scale features. Our proposal is to play on these two scales. First, by including geomorphological information into the ``distance'' field using a fast marching method. This custom ``distance'' field takes into account simultaneously various elements involved in the conduit genesis and so influencing the conduit shapes. Second, we propose to build the random field by combining different variograms and/or distributions following the geomorphological elements taken into account by the fast marching. Different synthetic models show that the generated conduit shapes are closer to what is observed in real conduits than with the previous workflow, while the variability of structures that can be modeled with ODSIM is preserved. }
    }