Surface Nuclear Magnetic Resonance Monitoring Reveals Karst Unsaturated Zone Recharge Dynamics during a Rain Event

Understanding karst unsaturated zone (UZ) recharge dynamics is crucial for achieving sustainable management of karst hydrosystems. In this paper, we provide the first report of the application of surface nuclear magnetic resonance (SNMR) monitoring of a karst UZ during a typical Mediterranean rain event. This 79 days’ SNMR monitoring is a part of a more than 2 years of SNMR monitoring at the Low Noise Underground Laboratory (LSBB) experimental site located within the Fontaine de Vaucluse karst hydrosystem (southeastern France). We present eight SNMR soundings conducted before and after the rain event that accumulated 168 mm in 5 days. The obtained results demonstrate the applicability and the efficiency of SNMR for investigating infiltration dynamics in karst UZs at the time scale of a few days. We present the SNMR amplitudes that highlight strong signal variations related to water dynamics in the karst UZ. Infiltrated water cause increased SNMR signal during 5 days after the rain event. A significant draining process of the medium starts 15 days after the main event. Finally, after 42 days, the SNMR signal returns close to the initial state.

[1]  M. Descloîtres,et al.  Time-lapse magnetic resonance sounding measurements for numerical modeling of water flow in variably saturated media , 2020, Journal of Applied Geophysics.

[2]  F. Fournier,et al.  Platform-to-basin anatomy of a Barremian–Aptian Tethyan carbonate system: New insights into the regional to global factors controlling the stratigraphic architecture of the Urgonian Provence platform (southeast France) , 2018, Cretaceous Research.

[3]  F. Fournier,et al.  The equivalent pore aspect ratio as a tool for pore type prediction in carbonate reservoirs , 2018, AAPG Bulletin.

[4]  H. Jourde,et al.  Assessment of groundwater recharge processes through karst vadose zone by cave percolation monitoring , 2018, Hydrological Processes.

[5]  C. Champollion,et al.  Monitoring Saturation Changes with Ambient Seismic Noise and Gravimetry in a Karst Environment , 2018 .

[6]  J. Chambers,et al.  Imaging groundwater infiltration dynamics in the karst vadose zone with long-term ERT monitoring , 2017 .

[7]  H. Davi,et al.  Process-Based Vegetation Models Improve Karst Recharge Simulation Under Mediterranean Forest , 2017 .

[8]  H. Jourde,et al.  Contribution of magnetic resonance soundings for characterizing water storage in the unsaturated zone of karst aquifers , 2016 .

[9]  H. Davi,et al.  The role of porous matrix in water flow regulation within a karst unsaturated zone: an integrated hydrogeophysical approach , 2016, Hydrogeology Journal.

[10]  H. Vonhof,et al.  Diagenetic patterns and pore space distribution along a platform to outer-shelf transect (Urgonian limestone, Barremian-Aptian, SE France) , 2014 .

[11]  C. Emblanch,et al.  Combining Electrical Resistivity Tomography and Ground Penetrating Radar to study geological structuring of karst Unsaturated Zone , 2013 .

[12]  F. Fournier,et al.  Diagenetic Patterns and Pore Space Distribution along a Platform to Outer-Shelf Transect (Urgonian Limestone, Barremian-Aptian, South-East France); #120074 (2013) , 2013 .

[13]  R. Soto,et al.  Characterization of a karstic aquifer using magnetic resonance sounding and electrical resistivity tomography: a case-study of Estaña Lakes (northern Spain) , 2012, Hydrogeology Journal.

[14]  J. Masse,et al.  Drowning discontinuities and stratigraphic correlation in platform carbonates. The late Barremian–early Aptian record of southeast France , 2011 .

[15]  Roger Guerin,et al.  Contribution of geophysical methods to karst-system exploration: an overview , 2011 .

[16]  J. Girard,et al.  Locating water-filled karst caverns and estimating their volume using magnetic resonance soundings , 2008 .

[17]  Jean-François Girard,et al.  2D magnetic resonance tomography applied to karstic conduit imaging , 2007 .

[18]  D. Ford,et al.  Karst Hydrogeology and Geomorphology , 2007 .

[19]  N. Dörfliger,et al.  Using 2D inversion of magnetic resonance soundings to locate a water-filled karst conduit , 2006 .

[20]  R. Guérin.  Borehole and surface-based hydrogeophysics , 2005 .

[21]  Jean-Michel Vouillamoz,et al.  Magnetic Resonance Sounding Applied to Aquifer Characterization , 2004, Ground water.

[22]  Y. Albouy,et al.  Localization of Saturated Karst Aquifer with Magnetic Resonance Sounding and Resistivity Imagery , 2003, Ground water.

[23]  Anatoly Legchenko,et al.  A review of the basic principles for proton magnetic resonance sounding measurements , 2002 .

[24]  J. Mudry,et al.  Dissolved organic carbon of infiltration within the autogenic Karst Hydrosystem , 1998 .

[25]  A. Legchenko,et al.  A new direct non-invasive groundwater detection technology for Australia , 1991 .