Seepage flow through embankment dams and their sub-base is a crucial safety concern that can initiate internal erosion of the structure. The thermometric method of seepage monitoring employs the study of heat transfer characteristics in the soils, as the temperature distribution in earth-filled structures can be influenced by the presence of seepage. Thus, continuous temperature measurements can allow detection of seepage flows. With the recent advances in optical fiber temperature sensor technology, accurate and fast temperature measurements, with relatively high spatial resolution, have been made possible using optical fiber distributed temperature sensors (DTSs). As with any sensor system, to obtain a precise temperature, the DTS measurements need to be calibrated. DTS systems automatically calibrate the measurements using an internal thermometer and reference section. Additionally, manual calibration techniques have been developed which are discussed in this paper. The temperature data do not provide any direct information about the seepage, and this requires further processing and analysis. Several methods have been developed to interpret the temperature data for the localization of the seepage and in some cases to estimate the seepage quantity. An efficient DTS application in seepage monitoring strongly depends on the following factors: installation approach, calibration technique, along with temperature data interpretation and post-processing. This paper reviews the different techniques for calibration of DTS measurements as well as the methods of interpretation of the temperature data.

Faculty of Civil and Geodetic Engineering University of Ljubljana Jamova cesta 2 1000 Ljubljana Slovenia

Faculty of Civil Engineering Brno University of Technology Veveří 331 95 602 00 Brno Czech Republic

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Garner S.J., Fannin R.J. Understanding internal erosion: A decade of research following a sinkhole event. Int. J. Hydropower Dams. 2010;17:93–98.

ICOLD . Internal Erosion of Existing Dams, Levees and Dikes, and Their Foundations. ICOLD; Paris, France: 2013.

Su H., Yang M., Wen Z. Multi-Layer Multi-Index Comprehensive Evaluation for Dike Safety. Water Resour. Manag. 2015;29:4683–4699. doi: 10.1007/s11269-015-1084-x. DOI

Ndour M., Chang K.T., Hossain S.I. Leakage detection in dam and reservoir using Optical Fiber Cable Sensor (FOCS ) based on Active Method; Proceedings of the 52nd The IRES International Conference; Kuala Lumpur, Malaysia. 5 November 2016; pp. 61–66.

Kappelmeyer O. The use of near surface temperature measurements for discovering anomalies due to causes at depths. Geophys. Prospect. 1957;5:239–258. doi: 10.1111/j.1365-2478.1957.tb01431.x. DOI

Pingyu Z., Thévenaz L., Yuanbao L., Yang Z. Design of Simulator for Seepage Detection in Embankment By Optic Fibre Sensing Technology. Chinese J. Sci. Instrum. 2007;28:431–436.

Johansson S. Ph.D. Thesis. Royal Institute of Technology; Stockholm, Sweden: 1997. Seepage Monitoring in Embankment Dams.

Nield D.A., Bejan A. Convection in Porous Media. Springer; New York, NY, USA: 2006.

Radzicki K., Bonelli S. Thermal Seepage Monitoring in the Earth Dams with Impulse Response Function Analysis Model; Proceedings of the 8th ICOLD European Club Symposium; Innsbruck, Austria. 22–23 September 2010; pp. 624–629.

Dornstadter J. Detection of internal erosion in embankment dams; Proceedings of the Nineteenth International Commission on Large Dams; Florence, Italy. 26–30 May 1997; pp. 87–102.

Yousefi S., Ghiassi R., Noorzad A., Ghaemian M., Kharaghani S. Application of temperature simulation for seepage inspection in earth-fill dams. Građevinar. 2013;65:825–832. doi: 10.14256/JCE.878.2013. DOI

Xu Z., Liu D., Liu H., Sun Q., Sun Z., Zhang X., Wang W. Design of distributed Raman temperature sensing system based on single-mode optical fiber. Front. Optoelectron. China. 2009;2:215–218. doi: 10.1007/s12200-009-0043-7. DOI

Ukil A., Braendle H., Krippner P. Distributed temperature sensing: Review of technology and applications. IEEE Sens. J. 2012;12:885–892. doi: 10.1109/JSEN.2011.2162060. DOI

Su H., Kang Y. Design of System for Monitoring Seepage of Levee Engineering Based on Distributed Optical Fiber Sensing Technology. Int. J. Distrib. Sens. Netw. 2013;10:358784. doi: 10.1155/2013/358784. DOI

Orrell P.R. Distributed Fibre Optic Temperature Sensing. Sens. Rev. 1992;12:27–31. doi: 10.1108/eb007876. DOI

Grattan K.T.V., Ning Y.N. Classification of optical fiber sensors. In: Grattau K.T.V., Meggitt B.T., editors. Optical Fiber Sensor Technology. Springer; Boston, MA, USA: 1998.

Smith E., Dent J. Modern Raman Spectroscopy: A Practical Approach. John Wiley and Sons; Chichester, UK: 2004.

Larkin P.J. Infrared and Raman Spectroscopy: Principals and Spectral Interpretation. Elsevier; Waltham, MA, USA: 2011.

Posey R., Johnson G.A., Vohra S.T. Strain sensing based on coherent Rayleigh scattering in an optical fibre. Electron. Lett. 2000;36:1688–1689. doi: 10.1049/el:20001200. DOI

Galindez-Jamioy C.A., López-Higuera J.M. Brillouin distributed fiber sensors: An overview and applications. J. Sens. 2012;2012:204121. doi: 10.1155/2012/204121. DOI

Zaixuan Z., Honglin L. The Optimum Designs of 30km Distributed Optical Fiber Raman. Adv. Sens. Syst. Appl. 2002;4920:268–273.

Long D.A. Raman Spectroscopy. McGraw-Hill International; New York, NY, USA: 1977.

Hartog A.H., Gold M.P., Leach A.P. Optical Time-Domain Reflectometry. US4823166A. United States Patent. 1989

Bolognini G., Park J., Soto M.A., Park N., Di Pasquale F. Analysis of distributed temperature sensing based on Raman scattering using OTDR coding and discrete Raman amplification. Meas. Sci. Technol. 2007;18:3211–3218. doi: 10.1088/0957-0233/18/10/S24. DOI

Yin S., Ruffin P.B., Yu F.T.S., editors. Fiber Optic Sensors. 2nd ed. Taylor & Francis; Boca Raton, FL, USA: 2008.

Odic R.M., Jones R.I., Tatam R.P. Distributed Temperature Sensor for Aeronautic Applications; Proceedings of the 15th Optical Fiber Sensors Conference; Portland, OR, USA. 10 May 2002; pp. 459–562.

Dakin J.P., Pratt D.J. SPIE Fiber Optic and Laser Sensors III. Volume 566. SPIE; Bellingham, DC, USA: 1985. Temperature distribution measurement using Raman ratio thermometry; pp. 249–256.

Vandenabeele P. Practical Raman Spectroscopy. John Wiley & Sons, Ltd; Chichester, West Sussex, UK: 2013.

Selker J.S., Thévenaz L., Huwald H., Mallet A., Luxemburg W., Van De Giesen N., Stejskal M., Zeman J., Westhoff M., Parlange M.B. Distributed fiber-optic temperature sensing for hydrologic systems. Water Resour. Res. 2006;42:1–8. doi: 10.1029/2006WR005326. DOI

Vogel B., Cassens C., Graupner A., Trostel A. SPIE’s 8th Annual International Symposium on Smart Structures and Materials. Volume 4328. SPIE; Newport Beach, CA, USA: 2001. Leakage detection systems by using distributed fiber optical temperature measurement; pp. 23–34.

Hausner M.B., Suárez F., Glander K.E., van de Giesen N. Calibrating Single-Ended Fiber-Optic Raman Spectra Distributed Temperature Sensing Data. Sensors. 2011;11:10859–10879. doi: 10.3390/s111110859. PubMed DOI PMC

Selker J.S., Tyler S., van de Giesen N. Comment on “Capabilities and limitations of tracing spatial temperature patterns by fiber-optic distributed temperature sensing” by Liliana Rose et al. Water Resour. Res. 2014;50:5372–5374. doi: 10.1002/2013WR014979. DOI

Smolen J.J., Van Der Spek A., Smolen J.J. Distributed Temperature Sensing: A DTS Primer for Oil & Gas Production. Hell International Exploration and Production; The Hague, The Netherlands: 2003.

Tyler S.W., Selker J.S., Hausner M.B., Hatch C.E., Torgersen T., Thodal C.E., Schladow S.G. Environmental temperature sensing using Raman spectra DTS fiber-optic methods. Water Resour. Res. 2009;45:11. doi: 10.1029/2008WR007052. DOI

Crisp J., Elliott B. Introduction to Fiber Optics. 3rd ed. Elsevier; Burlington, MA, USA: 2005.

Nikles M., Vogel B., Briffod F., Grosswig S., Sauser F., Luebbecke S., Bals A., Pfeiffer T. Leakage detection using fiber optics distributed temperature monitoring; Proceedings of the 11th SPIE Annual International Symposium on Smart Structures and Materials; San Diego, CA, USA. 14–18 March 2004; pp. 18–25.

Silixa Ltd. SILIXA XT-DTS Software Manual. Silixa House Elstree; Borehamwood, UK: 2014.

Hartog A.H. An Introduction to Distributed Optical Fibre Sensors. CRC Press, Tylor and Francis Group; Boca Raton, FL, USA: 2017.

Farahani M.A., Gogolla T. Spontaneous Raman Scattering in Optical Fibers with Modulated Probe Light for Distributed Temperature Raman. J. Light. Technol. 1999;17:1379–1391. doi: 10.1109/50.779159. DOI

Suarez F., Aravena J.E., Hausner M.B., Childress A.E., Tyler S.W. Assessment of a vertical high-resolution distributed temperature sensing system in a shallow thermohaline environment. Hydrol. Earth Syst. Sci. 2011:1081–1093. doi: 10.5194/hess-15-1081-2011. DOI

Hausner M.B., Kobs S. Identifying and Correcting Step Losses in Single-Ended Fiber-Optic Distributed Temperature Sensing Data. J. Sens. 2016;2016:7073619. doi: 10.1155/2016/7073619. DOI

van de Giesen N., Steele-Dunne S.C., Jansen J., Hoes O., Hausner M.B., Tyler S., Selker J. Double-Ended Calibration of Fiber-Optic Raman Spectra Distributed Temperature Sensing Data. Sensors. 2012;12:5471–5485. doi: 10.3390/s120505471. PubMed DOI PMC

Sanders P.E. OPN Optics & Photonics News. OSA Publishing; Washington, DC, USA: 2011. Fiber-Optic Sensors: Playing Both Sides of the Energy Equation; pp. 36–42.

Lee D.S., Park K.G., Lee C., Choi S.-J. Distributed Temperature Sensing Monitoring of Well Completion Processes in a CO2 Geological Storage Demonstration Site. Sensors. 2018;18:4239. doi: 10.3390/s18124239. PubMed DOI PMC

Fukuzawa T., Shida H., Oishi K., Takeuchi N., Adachi S. Performance Improvements in Raman Distributed Temperature Sensor. Photonic Sens. 2013;3:314–319. doi: 10.1007/s13320-013-0128-1. DOI

Johansson S., Watley D. Distributed sensing of seepage and movements using optical fibres—Results from some embankment dams in Sweden. Int. Water Power Dam Constr. 2004

Johansson S., Sjödahl P. Downstream Seepage Detection using Temperature Measurements and Visual Inspection—Monitoring Experiences from Røsvatn Field Test Dam and Large Embankment Dams in Sweden; Proceedings of the Stability and Breaching of Embankment Dams; Oslo, Norway. 26–27 April 2004; pp. 1–20.

Klun M. Ph.D. Thesis. University of Ljubljana; Ljubljana, Slovenia: 2020. Analysis of Concrete Gravity Dam Conditions using State-of-the-art Experimental and Numerical Methods.

Johansson S., Sjodahl P. Assessment of the Risk of Internal Erosion of Water Retaining Structures: Dams, Dykes and Levees. Technische Universität München; Munich, Germany: 2007. Seepage Measurements and Internal Erosion Detection using the Passive Temperature Method.

Adam K., Říha J., Špano M. Investigation on the temperature of the asphalt-concrete facing of embankment dams. Int. J. Pavement Res. Technol. 2016;9:73–81. doi: 10.1016/j.ijprt.2016.01.006. DOI

Dornstädter J., Heinemann B. Temperature as tracer for in-situ detection of internal erosion; Proceedings of the ICSE-6 (6th International Conference on Scour and Erosion); Paris, France. 27–31 August 2012.

Sjödahl P., Dahlin T., Johansson S. Embankment dam seepage evaluation from resistivity monitoring data. Near Surf. Geophys. 2009;7:463–474. doi: 10.3997/1873-0604.2009023. DOI

Claesson J., Dunand A. Heat Extraction from the Ground by Horizontal Pipes: A Mathematical Analysis. Swedish Council for Building Research; Stockholm, Sweden: 1983.

Khan A.A., Vrabie V., Mars J.I., Girard A., D’Urso G. A source separation technique for processing of thermometric data from fiber-optic DTS measurements for water leakage identification in dikes. IEEE Sens. J. 2008;8:1118–1129. doi: 10.1109/JSEN.2008.926109. DOI

Khan A.A., Vrabie V., Mars J.I., Girard A., D’Urso G. Automatic monitoring system for singularity detection in dikes by DTS data measurement. IEEE Trans. Instrum. Meas. 2010;59:2167–2175. doi: 10.1109/TIM.2009.2032880. DOI

Khan A.A., Vrabie V., Beck Y., Mars J.I., Urso G.D. Monitoring and early detection of internal erosion: Distributed sensing and processing. Struct. Heal. Monit. 2014;13:562–576. doi: 10.1177/1475921714532994. DOI

Mars J.I., Buchoud E., Vrabie V.D., Khan A.A., Blairon S., D’Urso G. Source separation and distributed sensing: The key for an efficient monitoring; Proceedings of the 2013 5th IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP); St. Martin, France. 15–18 December 2013; pp. 264–267.

Comon P., Jutten C., editors. Handbook of Blind Source Separation: Independent Component Analysis and Applications. Elsevier Ltd.; Burlington, MA, USA: 2010.

Beck Y.L., Khan A.A., Cunat P., Guidoux C., Artières O., Mars J., Fry J.J. Thermal monitoring of embankment dams by fiber optics; Proceedings of the 8th ICOLD European Club Symposium: Dam Safety-Sustainability in a Changing Environment; Innsbruck, Austria. 22–23 September 2010; Graz, Austria: Verl. der Techn. Univ. Graz; 2010. pp. 444–448.

Mars J.I., Khan A.A., Vrabie V., Girard A., D’urso G. Water Leakage Detection in Dikes by Fiber Optic; Proceedings of the 72nd EAGE Conference & Exhibition incorporating SPE EUROPEC; Barcelona, Spain. 14–17 June 2010.

Radzicki K., Bonelli S. Proceedings of the 20ème Congrès Français de Mécanique [CFM2011] Maison de la Mécanique; Paris, France: 2011. Impulse Response Function Analysis model application to the thermical seepage monitoring in the earth dams; pp. 1–6.

Bonelli S., Radzicki K. The Impulse Response Function Analysis of Pore Pressures Monitoring Data; Proceedings of the 5th International Conference on Dam Engineering; Lisbon, Portugal. 14–16 February 2007.

Artières O., Bonelli S., Fabre J., Guidoux C., Radzicki K., Royet P., Vedrenne C. Active and Passive Defences against Internal Erosion of Dikes; Proceedings of the Assessment of the Risk Internal Erosion of Water Retaining Structures: Dams, Dykes and Levees. Intermediate Report of the European Working Group of ICOLD; Freising, Germany. 17–19 September 2007; pp. 235–244.

Schäfer P., Perzlmaier S., Conrad M., Strobl T., Aufleger M. Rehabilitation of dam facings monitored by an advanced technology for leakage detection; Proceedings of the 21st ICOLD Congress; Montréal, Canada. 16–20 June 2003.

Perzlmaier S., Aufleger M., Dornstädter J. Detection of Internal Erosion by Means of the Active Temperature Method; Proceedings of the Assessment of the Risk of Internal Erosion of Water Retaining Structures: Dams, Dykes and Levees. Intermediate Report of the European Working Group of ICOLD; Oberaudorf, Germany. 17–19 September 2007;

Sayde C., Selker J., English M. Measuring Soil Moisture in a Heterogeneous Field; Proceedings of the World Environmental and Water Resources Congress; Kansas City, MS, USA. 17–21 May 2009; pp. 4372–4381.

Su H., Tian S., Kang Y., Xie W., Chen J. Monitoring water seepage velocity in dikes using distributed optical fiber temperature sensors. Autom. Constr. 2017;76:71–84. doi: 10.1016/j.autcon.2017.01.013. DOI

Kristiansen J.I. The Transient Cylindrical Probe Method for Determination of Thermal Parameters of Earth Materials. Laboratory of Geophysics, Aarhus University; Aarhus N, Denmark: 1982.

Sayde C., Gregory C., Gil-Rodriguez M., Tufillaro N., Tyler S., van de Giesen N., English M., Cuenca R., Selker J.S. Feasibility of soil moisture monitoring with heated fiber optics. Water Resour. Res. 2010;46 doi: 10.1029/2009WR007846. DOI

Cao D., Shi B., Loheide S.P., Gong X., Zhu H.H., Wei G., Yang L. Investigation of the influence of soil moisture on thermal response tests using active distributed temperature sensing (A–DTS) technology. Energy Build. 2018;173:239–251. doi: 10.1016/j.enbuild.2018.01.022. DOI

Apperl B., Bernhardt M., Schulz K. Towards improved field application of using distributed temperature sensing for soil moisture estimation: A laboratory experiment. Sensors. 2020;20:29. doi: 10.3390/s20010029. PubMed DOI PMC

Lagos M., Serna J.L., Muñoz J.F., Suárez F. Challenges in determining soil moisture and evaporation fluxes using distributed temperature sensing methods. J. Environ. Manag. 2020;261:110232. doi: 10.1016/j.jenvman.2020.110232. PubMed DOI

Aufleger M., Conrad M., Goltz M., Perzlmaier S., Porras P. Innovative dam monitoring tools based on distributed temperature measurement. Jordan J. Civ. Eng. 2007;1:29–37.

Domanski M., Quinn D., Day-Lewis F.D., Briggs M.A., Werkema D., Lane J.W., Jr. DTSGUI: A Python Program to Process and Visualize Fiber-Optic Distributed Temperature Sensing Data. Limnol. Oceanogr. 2019;64:1864–1882. doi: 10.1111/gwat.12974. PubMed DOI PMC

Radzicki K., Bonelli S. Monitoring of the suffusion process development using thermal analysis performed with IRFTA model; Proceedings of the 6th International Conference on Scour and Erosion; Paris, France. 27–31 August 2012; pp. 593–600.

Côté A., Carrier B., Gervais R., Noël P. Water Seepage Detection and Localization at the Péribonka Dam using Optical Fiber; Proceedings of the CDA 2008 Annual Conference; Winnipeg, MB, Canada. 27 September–2 October 2008; pp. 404–416.

Benítez-Buelga J., Sayde C., Rodríguez-Sinobas L., Selker J.S. Heated Fiber Optic Distributed Temperature Sensing: A DualProbe Heat-Pulse Approach. Vadose Zone J. 2014;13:1–10. doi: 10.2136/vzj2014.02.0014. DOI

McDaniel A., Tinjum J.M., Hart D.J., Fratta D. Dynamic Calibration for Permanent Distributed Temperature Sensing Networks. IEEE Sens. J. 2018;18:2342–2352. doi: 10.1109/JSEN.2018.2795240. DOI

McDaniel A., Harper M., Fratta D., Tinjum J.M., Choi C.Y., Hart D.J. Dynamic Calibration of a Fiber-Optic Distributed Temperature Sensing Network at a District-Scale Geothermal Exchange Borefield; Proceedings of the Geo-Chicago 2016; Chicago, IL, USA. 14–18 August 2016.

Ghafoori Y., Maček M., Vidmar A., Říha J., Kryžanowski A. Analysis of seepage in a laboratory scaled model using passive optical fiber distributed temperature sensor. Water. 2020;12:367. doi: 10.3390/w12020367. DOI

Araujo M.S., Spidle H.A., Siebenaler S.P., Blaisdell S.G., Vickers D.W. Application of Machine Learning to Distributed Temperature Sensing (DTS) Systems; Proceedings of the 12th International Pipeline Conference (IPC2018); Calgary, AB, Canada. 24–28 September 2018.