TY - JOUR

T1 - Feasibility study on prepolarized surface nuclear magnetic resonance for soil moisture measurements

AU - Hiller, Thomas

AU - Costabel, Stephan

AU - Radić, Tino

AU - Dlugosch, Raphael

AU - Müller-Petke, Mike

N1 - Funding information: We like to thank the associate editor and two anonymous reviewers for their valuable comments. Furthermore, we thank Kai Holtappels from the German Federal Institute for Materials Research and Testing for providing the necessary logistics to conduct our field experiments. We also like to thank Florian Stange and Axel Lamparter from the German Federal Institute for Geosciences and Natural Resources for providing us with the TDR equipment. This work was supported by the German Research Foundation under the grant MU 3318/4?1. We like to thank the associate editor and two anonymous reviewers for their valuable comments. Furthermore, we thank Kai Holtappels from the German Federal Institute for Materials Research and Testing for providing the necessary logistics to conduct our field experiments. We also like to thank Florian Stange and Axel Lamparter from the German Federal Institute for Geosciences and Natural Resources for providing us with the TDR equipment. This work was supported by the German Research Foundation under the grant MU 3318/4-1.

PY - 2021/9/25

Y1 - 2021/9/25

N2 - In the past few years, small-scale (2 m) prepolarized surface nuclear magnetic resonance (SNMR) has gained increasing interest in the research community. As recent studies demonstrated, the application of a strong prepolarization field enhances the SNMR signal of coils with a footprint <1 m2 up to a level that even enables investigations in urban areas. In particular, it is expected that this noninvasive method provides the soil moisture distribution in the upper 2 m of the subsurface in the near future. However, until now all field experiments have been carried out on water reservoirs only, in an approach to test and implement this rather new technique into the field of SNMR applications. We present the first prepolarized SNMR measurement on a real soil and demonstrate the general feasibility of this technique to qualitatively and quantitatively detect soil moisture in the upper first 0.5 m. Our soil moisture measurements are validated by independent time domain reflectometry data. To complement the field experiments with numerical simulations, we adapted the underlying SNMR spin dynamics simulations and account for prepolarization switch-off effects in the forward modeling of the SNMR excitation.

AB - In the past few years, small-scale (2 m) prepolarized surface nuclear magnetic resonance (SNMR) has gained increasing interest in the research community. As recent studies demonstrated, the application of a strong prepolarization field enhances the SNMR signal of coils with a footprint <1 m2 up to a level that even enables investigations in urban areas. In particular, it is expected that this noninvasive method provides the soil moisture distribution in the upper 2 m of the subsurface in the near future. However, until now all field experiments have been carried out on water reservoirs only, in an approach to test and implement this rather new technique into the field of SNMR applications. We present the first prepolarized SNMR measurement on a real soil and demonstrate the general feasibility of this technique to qualitatively and quantitatively detect soil moisture in the upper first 0.5 m. Our soil moisture measurements are validated by independent time domain reflectometry data. To complement the field experiments with numerical simulations, we adapted the underlying SNMR spin dynamics simulations and account for prepolarization switch-off effects in the forward modeling of the SNMR excitation.

UR - http://www.scopus.com/inward/record.url?scp=85111366759&partnerID=8YFLogxK

U2 - 10.1002/vzj2.20138

DO - 10.1002/vzj2.20138

M3 - Article

AN - SCOPUS:85111366759

VL - 20

JO - Vadose zone journal

JF - Vadose zone journal

SN - 1539-1663

IS - 5

M1 - e20138

ER -