1887

Abstract

Summary

The Lodève landslide is located 60 km northeast of Montpellier (South of France). It corresponds to a deep-seated landslide (up to 50 m depth) with a slow slip displacement (4–6 mm/year). In this area the landslide activity is associated with intense precipitations events (called “Cévenol events”, 300–500 mm in few days) and the related dissolution of Triassic evaporite layers at depth. Considering a relatively simple geological context and the presence of a unique triggering factor, this landslide corresponds to a preferential natural observatory to study the impact of large rain events on the slow slope kinematics. A downhole monitoring was conducted since 2012 in order to image the water flows within the landslide in order to better understand the role of fluids in the slope instability. The landslide is investigated down to 60 m depth by two in situ permanent observatories for a geophysical (electrical resistivity and deformation) and an hydrogeochemical monitoring (pressure, pH, temperature, electrical conductivity, fluid sampling). This instrumentation helps to identify and characterize the active slip zones in the underground. The first results point out the relevance of the downhole monitoring to progress towards a better understanding of internal landslide processes in relation to climate forcing.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201802647
2018-09-09
2024-03-29
Loading full text...

Full text loading...

References

  1. Binet, S., Jomard, H., Lebourg, T., Guglielmi, Y., Tric, E., Bertrand, C. and Mudry, J.
    , 2007. Experimental analysis of groundwater flow through a landslide slip surface using natural and artificial water chemical tracers. Hydrol. Process., 21: 3463–3472. doi:10.1002/hyp.6579
    https://doi.org/10.1002/hyp.6579 [Google Scholar]
  2. Bogaard, T. A., Greco, R.
    , 2016. Landslide hydrology: from hydrology to pore pressure. WIREs Water, 3, 439–459, doi:10.1002/wat2.1126.
    https://doi.org/10.1002/wat2.1126 [Google Scholar]
  3. Denchik, N.et al.
    , 2018. In-situ geophysical and hydro-geochemical monitoring for landslide dynamics (Lodève landslide, France). Submitted to Engineering Geology.
    [Google Scholar]
  4. Lofi, J., Pezard, P., Loggia, D., Garel, E., Gautier, S., Merry, C., Bondabou, K.
    , 2012. Geological discontinuities, main flow path and chemical alteration in a marly hill prone to slope instability: Assessment from petrophysical measurements and borehole image analysis. Hydrol. Process. 26, 2071–2084, doi:10.1002/hyp.7997.
    https://doi.org/10.1002/hyp.7997 [Google Scholar]
  5. Tsao, T.M., Wang, M.K., Chen, M.C., Takeuchi, Y., Matsuura, S., Ochiai, H.
    , 2005. A case study of the pore water pressure fluctuation on the slip surface using horizontal borehole works on drainage well. Engineering Geology, Volume 78, Issues 1–2, pp. 105–118, ISSN 0013-7952, https://doi.org/10.1016/j.enggeo.2004.11.002.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201802647
Loading
/content/papers/10.3997/2214-4609.201802647
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error